Brake line question for 66 with disc brakes, dual master with proportioning valve.

Ok...here's my delimma. I have a the dual resevoir fat corvette style master cylinder with a disc/drum porportioning valve. I ordered a pre-bent 66 L-79 front to rear brake line. The problem is the line goes from the front to the rear on the passenger side. This is not correct for a dual master cyl car (such as the 67). The 67 ( I was told) goes up the driver side through the steering knuckle direct to the master cyl/proportioning valve. A single resevoir master cyl line would come up and meet on the passenger side front brake line. Is this correct?

Questions:

1) should I just splice in the L79 brake lines as it comes up the passenger side and run it across the front frame brace over to the driver side where the master cyl/prop valve is?
2 should I just order a pre-bent 67 brake line and hope it comes close to my aftermarket proportioning valve?
3) should I just make a front to rear brake line from scratch?


Here is my master cyl and proportioning valve:
http://i5.photobucket.com/albums/y178/FunkyuNova66/Mastercylwpropvalve001.jpg


Is this where my front brakes connect?
http://i5.photobucket.com/albums/y178/FunkyuNova66/Mastercylwpropvalve002.jpg


Is this where my rear brakes connect?
http://i5.photobucket.com/albums/y178/FunkyuNova66/Mastercylwpropvalve003.jpg


What is this plastic peice? A bleeder? How do I properly bleed this dual cyl master cyl through the proptioning valve?
http://i5.photobucket.com/albums/y178/FunkyuNova66/Mastercylwpropvalve004.jpg

What's the brass fitting on the rear section of the proportioning valve? Is this the adjustment for the front to rear valve?
http://i5.photobucket.com/albums/y178/FunkyuNova66/Mastercylwpropvalve005.jpg


Sorry for all the dumb questions. :D

Dave

Hi Dave,

I don't know for sure, but a pre-bent line for a 67 may come close to what you need. You will likely have to re-bend it a little to fit your proportioning valve. And the flare nut on the end of the 67 line probably won't screw directly into the proportioning valve. You will likely need to use an inverted flare adapter (available at most auto parts stores).

If you decide to make your own line, you can buy a roll of steel brake line at many auto parts stores. You will also need to buy the appropriate size flare nuts and may still need to use an adapter to fit the rear brake line outlet of the proportioning valve. The rear outlet takes a flare nut that has larger threads than what is normally used on 1/4" line. You will also need a good double flaring tool.

Another option is to purchase pre-flared lengths of steel brake line. The max length available is either 60" or 72" so you will have to join two sections together with a coupler. Again, you'll probably need an adapter to fit the proportioning valve since the pre-flared brake lines have "standard" sized flare nuts on them.

The two small ports (your photos #2 and #3) are where the front brake lines connect. The proportioning valve has a built-in Tee so there are two front outlets. It doesn't matter which one you use as far as left/right goes. You could even install an inverted flare plug in one and run a single line to a separate Tee fitting for the front brakes.

The plastic piece (your photo #4) is the connector for the pressure differential switch. This can be used to add a "BRAKE" warning light to your dash that will come on if you loose pressure in either the front or rear brake system. Run a wire from this connector to one side of the bulb. Run a wire from the other side of the bulb to a +12V source that is switched via the ignition switch.

As for bleeding the dual MC through the proportioning valve, you shouldn't have to do anything special. Just bench bleed the master cylinder, hook it to the proportioning valve, and finish bleeding the system through the bleeder screws at the calipers & wheel cylinders.

The brass fitting at the rear of the proportioning valve (your photo #5) is where you connect the rear brake line. It appears as though your proportioning valve may have already come with the adapter fitting that I mentioned earlier. If that is the case, the standard size inverted flare nut on a 1/4" brake line should screw right into that adapter.

The "proportioning" valve you have is basically a copy of the GM combination valve that was used on many 1971-up vehicles with front disc brakes. The original GM ones were cast iron though. These valves contain a metering valve for the front disc brakes. It slightly delays the application of the front brakes to help reduce pad wear and help rear end stability. The porportioning valve section is non-adjustable.

Hey Ray, you sound very knowledgeable about this... i have the same valve on my master. the fitting in the rear of unit was removed by the salesman at time of purchase because i was running 4 whl discs and he said it was only needed for drums... does this sound right to you ???

i hope this in a way helps you too Dave... yer runnin' discs too aren't you ???


don't mean ta take off subject if yer runnin' drums. ;)

Hi Flyer,

If you look closely at Dave's last photo, you can see what looks like a large nut/fitting on the back end of the combo valve and another adapter screwed into that.

The adapter simply changes the size of the threads so a regular size brake line nut will fit.

The larger nut/fitting that screws into the combo valve holds the proportioning valve in place. I'm not all that familiar with the internals of these aftermarket style combo valves, but it may be possible to simply remove (and leave out) the proportioning valve section for use with 4-wheel disc. Of course, that large nut/fitting would need to be put back in place so you have a place to attach the rear brake line.

OK thanks... the fitting on mine had the same size in, as out, so the brake line fitting will fit directly into valve... he just removed that fitting.


i was considering an adjustable valve and do away with the supplied one... but thought i'd ask about it...

Thanks again :)

Ray...you have been a huge help. Thanks for spending the time to respond. Ok...let me make sure I have this straight.

The front has seperate lines going to each side? These go to the front side of the proportioning valve in the two seperate outlets? Do I need to plug of my T-blocks where the lines are no longer coming out to feed the passenger front and the rear?


The rear brakes have one line feeding both rear drums. This comes in through the back side of the proportioning valve. is this correct?

Couldn't I just splice in the passenger side where the rear line comes up and run it across where the factory front brake line is run across the frame support to the rear side of the proportioning valve? I'd hate to not use the pre-bent L-79 brake line I already bought but I am up for suggestions.:D

Dave

Hi Dave,

You're welcome.

You have a choice as to how you plumb the front brake lines. You could either:

(A) Make use of the proportioning valve's built in Tee. For this, you would run a line from one of the prop valve front outlets to the LH caliper and a separate line from the other prop valve front outlet to the RH caliper. You'd have to bend your own front lines for this configuration.

(B) Make use of the existing front brake lines and Tee block to feed the front brakes. For this, you would plug one of the prop valve front outlets using a special inverted flare plug. Then run a line from the other prop valve front outlet down to the stock driver side Tee block. You may even be able to re-use the line that connected to the old master cylinder for this (otherwise bend your own). You would also need to install an inverted flare plug in the outlet of the passenger side Tee block where the old rear brake line used to connect.


As for the rear, yes, there is one line that comes out of the back of the prop valve and feeds both rear brakes. There's usually a factory Tee fitting built into the end of the rubber flex line that connects to the rear axle.

Your idea of using the new L-79 rear brake line you already have should work. With an appropriate sized inverted flare coupling, you should be able to connect on an "extension" line and run it across to the driver side and connect it to the rear outlet of the prop valve.

Thanks Ray!

Makes perfect sense. Good news. I have the rear brake lines completed under the hood and it actually looks really clean and nice...I used the new aftermarket front to front brake line as a template when I bent the 1/4" rear tubing to run across frame support. I just added some extra on each side to splice into the components (prop valve and L-79 front to rear brake line).

....However, I have some more questions.:D

Why is there a 1/4" brake line going from the rear resevoir of the master cyl to the rear section of the prop valve only to come out the rear prop valve as a 3/16"?

The front to rear L-79 brake line I bought is a 1/4" line. So the line I created (bent) that splices into the the passenger side L-79 front to rear brake line that runs across the front frame support over to the rear section of the prop valve is also 1/4". However, I had no choice but to run a 3/16" line out the rear prop valve and splice it into the 1/4" line (I created) about 5" below the master cyl.:confused: :confused: I just don't understand why the inverted flare coming out the rear prop valve is only 3/16" when everything else (line between master cyl and prop valve and the entire rest of the rear front to rear brake line) is 1/4"... Seems ascinine to me.

Also....I bought a aftermarket factory front to front brake line for my 66. Now the fittings on the aftermarket front to front line is smaller than the factory. I think (b/c I threw out the old brake line away:o ) both (factory and aftermarket) front to front brake lines were 3/16 however the fittings on the end are different sizes. The fittings are too small on the aftermarket front to front brake line to screw into the blocks. :confused: :confused: So it looks like I need to cut the aftermarket lines where the flares are and run a bigger 3/16 fitting with bigger threads and re-flare. :confused: :confused: or should I just try and find an inverted flare and adapt it in? I am having a hard time finding inverted flares with different sizes going in and out of them. Seems they are always 3/16 in and 3/16 out. 1/4 in and 1/4 out..

I am so sick and tired of trying to peicemeal these brakes together. I guess this is the punishment when you try to build the non-factory brakes from scratch. I have made over 6 trips to the hardware stores and autoparts stores trying to find inverted flares, tubes, etc that nobody carries. What a PITA! I get the deer in the headlights look.:eek: :confused: :eek:

Everything else I have under control. I even have the plug for the passenger side block rear exit hole.
Hope I didn't confuse you.:D Ray..you have been a huge help! Thanks again for all the help you have given me thus far.

Dave:)

Hey Funky, check out this link from MP Brakes - http://www.mpbrakes.com/typical.htm. Since you are running a disc/drum setup, you will need to install a residual valve between the mc and the rear brake wheel cylinders - preferrably on the firewall. I think the prop valve you have does not include the residual valves. That is why you have 3/16 threads on all the ports. For a disc/drum set-up you need to run 3/16 line for the front discs (which you did) and 1/4 line for the rear drums. If running 4 wheel disc, then use 3/16 all around. I think since your prop valve has a 3/16 port out the rear that the residual valve will have a 3/16 in and 1/4 out. You can check with MP or other brake vendors on that. If so, that will solve your problem. Also, you may want to make sure your prop/combo valve is for a disc/drum system. BTW, the residual valve keeps pressure in the rear line assuring that the brake shoes do not retract too far from the drums when the brakes are not applied. This will give a firmer pedal when you do apply the brakes.

Humm...never knew about a residual valve.:eek:

EDIT: I just ordered a residual valve for my set up. Damn...looks like now I am gonna have to revisit all my rear plumping again. Last thing I need is spongy brakes. They were spongy before I tore it apart so no need to revisit this again. Thanks for bringing this to my attention! I HATE BRAKES!!! URGGG!!!!!

Dave :)

Funky, don't feel that you are alone on this issue. I have 4 or 5 different tubing benders and 3 different flaring tool kits, and I've gone through countless lengths of well-intented, pretzeled brake lines. I'd almost bet that somewhere in my (currently frozen) garage I might even have that fitting you were looking for. Just think, after this job, you'll be much better equipted to take on another brake line plumbing job.:D I'll bet you can't wait:D

Funky, don't feel that you are alone on this issue. I have 4 or 5 different tubing benders and 3 different flaring tool kits, and I've gone through countless lengths of well-intented, pretzeled brake lines. I'd almost bet that somewhere in my (currently frozen) garage I might even have that fitting you were looking for. Just think, after this job, you'll be much better equipted to take on another brake line plumbing job.:D I'll bet you can't wait:D
So true. I have like 10 of each different types of fittings Inverted flares, adaptors, tons of the short twisted lines (<---non which work:rolleyes: ). Flare tool that is supposed to be good but only half as$ works..:rolleyes: Tubing bender than can only bend tubing so tight...:rolleyes: and to buy pre-bent brake lines ****$ only to find out I ordered the wrong set or the fittings won't work with my factory blocks just chaps my as$!!!! Then to top it off...eveytime I go to get something to adapt two incompatible lines NOBODY has the brass flare fittings. God forbid I walk in an auto parts store and ask for plain brake lines or inverted flares!!:rolleyes: :rolleyes: :mad:

I walk in and ask..."Where is your bolt drawer in the back?" Thanks....

/Rant off:D

Hey Dave, I can't tell for sure from your firewall pic, but it looks like your Nova may have been a powerbrake car. Is that true? Anyway, my 63 was and now I'm converting to a manual master cyl. Since I can't use the power booster push rod with the new m/c I need to fab one. Do you have or can you take a pic of the manual push rod that you are using? If not, just let me know what the overall lenght of it is - if you can......Thanks...Frank

Hey Frank,

I can tell you my sedan was a factory single resevoir non-power brakes system.
'
Here you go....to a brutha from anotha mutha! I will measure the rods length when I pull the master cyl back out to paint it with a cast color. Otherwise it will probably be rusted in just a matter of time.
http://i5.photobucket.com/albums/y178/FunkyuNova66/DEC2005.jpg


JUST AN FYI TO EVERYONE EVER CONVERTING TO DUAL MASTER CYL:
#1 The front to front brake line on a single master cyl set up is 1/4". This is because the front brake line has to feed the entire brake system (rear too). It's one continuous 1/4" line.
#2 This also means on a factory single resevoir set up.. the front T-Blocks and metal lines that feed the front brakes are fitted for a 1/4" brake line going into the T-Block.
#3 The front to front brake line on a dual master cyl set up is 3/16". This is because the front brake line only feeds the front brakes and the rear brakes are feed by an entirely different different brake line that is 1/4".
#4 This also means on a factory dual resevoir set up... the front T-Blocks and metal lines that feed the front brakes are fitted for a 3/16" brake going into the T-Block.

LAST BUT NOT LEAST. The front to back brake line for a single resevoir runs up the passenger side and the for a dual resevoir runs up the drivers side.

MAKE SURE YOU ASK BEFORE YOU ORDER ANYTHING IF YOU DON'T KNOW! I'D BE HAPPY TO SHARE MY EXPERIENCES WITH YOU AND WALK YOU THOUGH WHAT TO DO.

If I had only known then what I know now I would have ordered everything correctly in the first place......:rolleyes: :rolleyes:

Live and learn,:o
Dave:)

Dave, thanks for the pics and the list of info on the m/c conversion. Rest assured that will help many of us here. If and when you pull the m/c that push rod length dimension will really help me out.....Frank

Dave, thanks for the pics and the list of info on the m/c conversion. Rest assured that will help many of us here. If and when you pull the m/c that push rod length dimension will really help me out.....Frank
No problem. I will definately get this measurement for you. I will pull the master cyl once I get the brake lines completed and mocked up. (2-3 days?)

So...I get me residual valve in today. Look at the box it's in and it appears they put the residual valve in backwards. No big deal...but don't show the flow going in the wrong directions on the box if your employees can't stick the valve in the box in the right direction.http://i5.photobucket.com/albums/y178/FunkyuNova66/smileys/icon_pissed2.gif

One other question:
What in the world does it mean by: "Locate valve lower than wheel cylinders or calipers"??????!?!?!? http://i5.photobucket.com/albums/y178/FunkyuNova66/smileys/rolleyes2.gif
It tells me to "insert valve in line close to master cyl" ...OK....whats the point of telling me to locate valve lower than wheel cylinders or calipers.

Since I paid $26 for this measly part, It would be nice to be a little more clear on the instructions not to mention stick the part in the package so the flow diagram matches the box.http://i5.photobucket.com/albums/y178/FunkyuNova66/smileys/rolleyes2.gif

http://i5.photobucket.com/albums/y178/FunkyuNova66/DEC2005109highlighted.jpg

Funky,
Where did you get your mastercyl, and pro port. valve from? I
got the kit from CPP, and mine has the residual valve built in,
makes it easier to hook up.
I used 67 brake line kit, manual disc, with drum rear. The original
push rod worked fine for me, no mods. I had to use a different
bushing to hook up the rear brakes at the back of master cyl.
I mounted a line lock on the ppv that's why the bracket isn't on
the master cyl, I'll add it this winter. Brakes work great.
Good luck, Rich

Funky,
Where did you get your mastercyl, and pro port. valve from? I
got the kit from CPP, and mine has the residual valve built in,
makes it easier to hook up.
I used 67 brake line kit, manual disc, with drum rear. The original
push rod worked fine for me, no mods. I had to use a different
bushing to hook up the rear brakes at the back of master cyl.
I mounted a line lock on the ppv that's why the bracket isn't on
the master cyl, I'll add it this winter. Brakes work great.
Good luck, Rich
Honestly, I can't remember. I bought it from a large vendor at the Carolina Auto Fest at Lowes Motor Speedway during the fall. I'll check the receipt when I get home. I believe it was CPP but not sure. I will then go online to see if the proportioning valve that I have has a built in Residual Valve. If so, I don't need to install the one I have otherwise I could have big problems. This would mean I have too much residual pressure and my brakes would probably not release once the pedal is depressed.

Do you have 4-wheel disc brakes or front wheel disc brakes?> ..curious.

Thanks a ton for bringing this to my attention Rich.

Regards,
Dave

Funky,
Iv'e got disc front, and drum rear, no power booster.
I'm sure if you called CPP they would tell you how to
identify which one you have.
Here's one more view.
Good luck, Rich

I'll call and find out. By the looks of yours it does appear to be almost exact so I am pretty sure it does have a built in residual valve. We'll see. That will be an easy install if I do need to add it.
Check it out. I salvaged the 66 front to rear brake line. :D
I ran the rear brake line simultaneous across the front support brace with the front to front brake line. If there is a will there is a way. I also used those tabs Novatorious used and doubled them up to try to keep the lines evenly spread. I also ran it double up on the support brace. Came out pretty clean. I'm happy with it. .
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005130.jpg

Here is the driver side. Note how I used the same clips to hold me wiring harness and windshield washer tubing.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005111.jpg

Here is a pics straight on.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005126.jpg

Under the rocker with fuel and brake line mounted together.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005132.jpg
Rear subfame area.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005131.jpg

Underside facing front frame support. Note how I mounted the lines on the frame support. The are going nowhere..lol.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005134.jpg

Near front rear spring perch.

http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005136.jpg

Fuel line I made to finish off the L-79 3/8 pre-bent line. I didn't realize it was two pieces....so I made this little section.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005117.jpg

Looks sweet Funky - nice work! BTW, love that garage floor:D

Looks sweet Funky - nice work! BTW, love that garage floor:D
Thanks Fast65! I do love the floor. It is a must for all hot rodders.:D DriveWFO just did his and it turned out really nice.

I have floor envy, too!

Funky, I'm 99% sure the prop valve you have includes the residual pressure valve. These are aftermarket GM replacements, and the vehicles they were originally used on didn't have separate Residual Pressure valves. (replaced the lines & old rusted valve on my 82 Blazer plow truck last year - it uses the same prop valve, only mounted under the core support - no other valves). I believe the brake companies typically market the RP valves to street rodders who use low mounted master cylinders (where the mc might be physically lower than the wheel cylinders) to maintain pressure at the wheels in drum setups.

You're right about the 67's rear line running down the drivers side - I bought my 1/4" stainless rear line from RightStuff detailing and it fits nicely & pops up right behind the mc, but I believe as someone else stated that I will have to adapt the fitting where it goes into the prop valve when I convert to front discs very soon. I originally used the line on the old drum/drum setup I was using until last year - not done with the new front end yet! It should look like Rich's when it's done - same mc & valve.

Looks like you've done a great job of adapting to the situation. No doubt you're frustrated, but don't feel too bad - lots of us have been there. I bought prebent lines for the Blazer last year, thinking that would be the easy way to go, and that was no picnic, either. I forgot the factory puts them in before all the other stuff (axles, exhaust, etc.) and it was a major pain. When it comes to custom bending, I've been there recently myself. Lots of scrap. I learned to practice with the cheap stuff. I'm impressed you were able to do with with only 6 trips to the store!

Thanks alot 1BluII! I think you are right about the residual valve. 99% sure myself. I can always try it like it is and see what happens. I think the brakes are gonna work like a champ. Especially going from a single resevoir to a dual resevoir with a proportioning valve and front disc brakes. We'll see.

My next feat is the front suspension, lokar floor shifter and new 9" center section. Then off to the motor install and frame connectors.

It's coming together slowly but surely. Thanks for the nice words.

Dave

HI FUNKY,THAT'S SOME JOB YOUR DOING:D TAKE YOUR TIME AND IT WILL COME OUT GREAT.HOW COME EVERYONE'S GARAGE LOOKS THE SAME?:confused: WELL EXCEPT FOR THE FLOOR.TOO CLEAN:D JUST A TIP,GET THE BRAKE SYSTEM WORKING BEFORE YOU PUT THE MOTOR IN TO CHECK FOR LEAKS.EASIER TO DO PAINT TOUCH UP.ALSO CHECK YOUR SUB FRAME CONNECTOR WHERE IT MOUNTS ON THE PASS SIDE.YOUR LINES MIGHT BE TOO CLOSE FOR IT TO FIT.I RAN MY BRAIDED LINE THERE AND HAD TO MOVE IT TO MAKE IT FIT.I ENDED UP RUNNING MY BRAKE LINE DOWN THE DRIVER SIDE. I TOO BOUGHT STOCK LINES FOR THE DRUM BRAKES.THEN BOUGHT A THE DISC BRAKE KIT AND NEVER USED THEM.KEEP UP THE GOOD WORK!!!!

Thanks Novafied! Great points! Fortunately, I installed the frame connectors in its positions before I installed the brake and fuel lines. I also considered where I fastened the lines to account for the frame connector mounting points. So I should be good there. I planned to bleed the brakes before I move forward. This would definately be much easier to look for leaks, etc. Glad to know I'm not the only one with brake/fuel line delimmas.:D

Dave:D

HI FUNKY,GLAD TO HELP OUT.I DID JUST ABOUT EVERYTHING YOUR DOING NOW SO I KNOW SOME OF THE PROBLEMS YOU WILL HAVE.I NOTICED ONE THING MORE.I THINK THAT SPRING ON YOUR FUEL LINE IS SUPPOSE TO GO IN THE FRONT WHEEL WELL SECTION TO PROTECT THE LINE FROM DAMAGE.WHEN I TOOK MINE APART,THE SPRING WAS THERE.I DON'T HAVE A PHOTO TO SHOW YOU,BUT MAYBE SOMEONE ELSE COULD CONFIRM THIS:confused: AGAIN,NICE JOB.

Great job as usual Funky! I believe novafied is correct on that
spring position on the front section.

I'm posting a pic of the center section of the line where it passes
the floor pan brace. As delivered the prebent line look's just like
the one you have pictured. I didn't like the way it was bent, and
caefully twisted the long portions of the line holding the 90's on
each end to change the position of the center kick out. It fits
much better now, and the whole line is closer to the floor pan.
I hope someone posts a pic of a original L79 nova to compare
it with.

My front section was made from 3/8 aluminum line. It didn't come as part of my pre-bent L-79 steel fuel line that I bought from Goodmark. :confused: :confused: So I actually made the front section out of aluminum tubing and I had no spring to slide over it. Where can I get the spring I can easily install it and connect the splice back.

Hope this makes sense.

Dave

Hey "Funky Nova 66"

Did you ever figure out how to get the 1/4" fuel line to the rear of you're proportioning valve? I have the same fitting that takes a 3/16" line. I'm replacing my single well with a dual well with prop. valve that I bought through modern performance as a kit. I have disk in front and drums in rear. Let me know how you came out before I go through the same head aches you've been through.

Thanks Chuck:confused:

Funky:

I like your work! Looking good! After reading about your residual valve problem I decided to call Modern Performance where I purchased mine. The guy told me the combination valve and residual valve are built into the proportioning valve. (by the picture mine looks just like yours, it's an after market built just for this conversion) I believe reading the forms that the residual & combination valves are used if you're not using proportioning valve. Depending on where your m.c. is located you might need a residual valve in each line plus the combo. valve. Makes since. I got this info. in the earlier form at web site www.mpbrakes.com.

Chuck:)

Hey "Funky Nova 66"

Did you ever figure out how to get the 1/4" fuel line to the rear of you're proportioning valve? I have the same fitting that takes a 3/16" line. I'm replacing my single well with a dual well with prop. valve that I bought through modern performance as a kit. I have disk in front and drums in rear. Let me know how you came out before I go through the same head aches you've been through.

Thanks Chuck:confused:
Hey Chuck,
I ended up running a 3/16 line out of the rear of the proportioning valve and stepping up to a 1/4 inch about 6" down. It really couldn't matter because the rear exit proportioning valve body is 3/16 anyway. Even if you had a 1/4" line coming off the rear, the fitting inside is still only 3/16. Let me know if you need any input. Thanks for calling Master Power Brakes about the residual valve. I think I have the same set up even though I bought mine through a different brake vendor at a large swap meet. Oh well...:rolleyes:..if someone needs a residual valve, let me know.:D

Dave

:) Am new to this site and the world of Novas. Inherited a 63SS and am presently in the restoration process. Will have front disc and rear drum brakes. I read all the posts you all got going on brake lines and valves, but am still slightly confused when it comes to size of brake lines when converting to dics.:confused: I will be replacing the brake lines. On my 63 the front line is the 1/4'' (thick line) and the rear line that connects to the front tee on the passenger side is the 3/16" ( thin line). Is this correct? I thought the lines on single M/C were 1/4" all the way around. Anyway my question is, since I will be switching to dual M/C, do I need to reverse the line size? 3/16 front and 1/4 rear. Do I order lines for a 67 or 63. Does line size matter? Can I keep it as is and just order a front to rear line for a 67 that is pre- bent to come up the driver side? Thanks for anyone that is willing to share. Sorry I have no answers just questions.

:) Am new to this site and the world of Novas. Inherited a 63SS and am presently in the restoration process. Will have front disc and rear drum brakes. I read all the posts you all got going on brake lines and valves, but am still slightly confused when it comes to size of brake lines when converting to dics.:confused: I will be replacing the brake lines. On my 63 the front line is the 1/4'' (thick line) and the rear line that connects to the front tee on the passenger side is the 3/16" ( thin line). Is this correct? I thought the lines on single M/C were 1/4" all the way around. Anyway my question is, since I will be switching to dual M/C, do I need to reverse the line size? 3/16 front and 1/4 rear. Do I order lines for a 67 or 63. Does line size matter? Can I keep it as is and just order a front to rear line for a 67 that is pre- bent to come up the driver side? Thanks for anyone that is willing to share. Sorry I have no answers just questions.I will try to take a crack at this.....

My factory 66 front to rear brake line was 1/4" and it feeds drum brakes on my 9" rear. My front to front brake line is 3/16 and it feeds my discs on front. The only time you would see 1/4 brake line up front is when you have a pre-67 single brake line system which feeds both the front and rear brakes (one continuous line). I am suprised to hear your front to rear line on your 63 drops down to 3/16 from 1/4 front line. Maybe someone else can chime in with some more input regarding this.:confused: I assume the front 3/16 brake line doesn't need to be as large when running a dual master cyl which feeds a seperate line to feed the disc brakes up front.

Your plan for your 63:

Disc up front and drums on rear


Dual Master cyl.

My suggestions:

Order the correct 67 front to rear 1/4" brake line which comes up the drivers side near the steering box. I AM ASSUMING A 1st Gen (62-63) and 2nd Gen (66-67) Nova has the same body dimensions underneath. We really need to get a definative answer from someone else!

Order a front to front brake line for a 67 with manual discs. I only say this to be as correct as possible. I am almost certain it will be a 3/16 line and not a 1/4" line. Call and ask. Mine was. If someone can confirm it does not matter if the line size is 1/4 or 3/16 when using discs up front, then use the one you have. I honestly don't know if it matters.

Order a dual master cyl for a manual disc/drum set up (it must have an proportioning valve) This helps regulate the pressure differences needed for drums and discs. If you have to order a late model large dual master cyl like mine with an external proportioning valve you will have to fabricate short lines to go to the proportioning valve.

REMINDERS: you may want to go ahead and order the correct t-blocks in the front while your at it. Remember....your front to rear line will not be coming off the passenger block anymore so you would have to plug it anyway. Plus... If I remember correctly, I had to use a lot of inverted flare fittings to get the new 3/16" front to front brake line (for discs) to fit on the T-blocks where my old 1/4" front to front brake line ("for drums) used to go. Probably would be cheaper to go ahead and get the correct ones rather than buy all the brass adaptor fittings to make it all work. Ask me how I know...:rolleyes:

Anyways...hope all this makes sense. If your still confused let me know and I will try and be a little more clear. We need to find out if the 63 and 67 brake lines are interchangable. Hard to tell from the catalogs when 62-66 never had dual master cyl. option.

Good luck
Dave:D

Thanks FunkyNova66
Great writeup. Things are becoming more clear. I did double check the rear break line and it is the thin line 3/16", I thought I might have confused it with the fuel line since it runs along side the brakeline. I also have a 66rearend that I will be using to replace my four lugger and it too has the small brake lines going to each of the wheel cylinders. Anyway thanks, maybe someone else can clear it up or maybe it does not matter. Might have to do with engine size, rearend is a 10 bolt, 8.2, 308.

Hey guys:
I have the same problem. My 63 was already converted to front disc rear drums but still has single well m.s.. I'm in the process of changing to dual well with proportioning valve. (special made for disc drum conversion) My problem is at the t block on passenger side the rear brakes are fed by 3/16" line. Previous owner ran all new lines from t block to both rear wheel cylinders. Everything from the t block forward is 1/4". I sure hate to tear out perfectly good line if I don't have to? My plan was to disconnect rear line at t on passenger side and put a plug in then splice new line and continue rear line along side the cross member and connect to rear of prop. valve. Leave existing 1/4" line for front and connect to front of prop. valve. Plug the extra outlet at valve also. Was the original line to rear 1/4" ? If so why the hell would someone go smaller? Sure would like some professional help with this.

Thanks Chuck:confused: :mad:

Hey guys:
I have the same problem. My 63 was already converted to front disc rear drums but still has single well m.s.. I'm in the process of changing to dual well with proportioning valve. (special made for disc drum conversion) My problem is at the t block on passenger side the rear brakes are fed by 3/16" line. Previous owner ran all new lines from t block to both rear wheel cylinders. Everything from the t block forward is 1/4". I sure hate to tear out perfectly good line if I don't have to? My plan was to disconnect rear line at t on passenger side and put a plug in then splice new line and continue rear line along side the cross member and connect to rear of prop. valve. Leave existing 1/4" line for front and connect to front of prop. valve. Plug the extra outlet at valve also. Was the original line to rear 1/4" ? If so why the hell would someone go smaller? Sure would like some professional help with this.

Thanks Chuck:confused: :mad:I don't know..I did exactly what you are talking about other than my newly ordered 66 L-79 front to rear line was 1/4. Maybe 63s only had 3/16 front to rear...not sure.

I would think someone with a 63 could check their factory one for you. Maybe the guy ordered it for a factory 63 not caring about diameter size.:confused:

Good question.

Anyone?

:) Finally remembered that Terry has a very nice writeup on his website that will put an end to all our questions. www.angelfire.com/nv/conv/ Hope this helps. Hope I won't get in trouble for mentioning the website.

Thanks Jay I needed that!!:D :D

My '65 has the skinny line to the rear brakes. GM must have enlarged the line sometime later on. Maybe in '66 with the change in body style.
You've gotta remember though that this is a pressure system, not a flow system, so very large lines are not needed. The wheel cylinders at the rear do not have to move very far to engage the brake shoes. Once the shoes are touching the drums, there is very, very little movement. You push harder on the pedal and you increase pressure on the pads, but they are already touching the drum so you just compress the pad slightly, force the drum out a bit, and expand the lines a tiny bit. We're talking stuff you would measure with a micrometer here though! So, a 3/16" line only has to be adaquete to move enough fluid to get the shoes into contact with the drums. After that, the line could be even smaller - all it has to do is transmit pressure.

When I did my front disc conversion, I just scavanged a complete brake line set off a dual circuit car (actually was a newer Nova). That got me all the right size fittings to go with the combo valve and whatnot. Plus, I had tons of brake line to bend up and reflare to fit.
I ran my line to connect to the rears up above the master on the firewall, which I think was a mistake. I'm pretty sure I've got some air trapped up there that I can't bleed out because it is too high.

I have a 64 Chevy II ,drums front and back, that I am going to put a dual master cylinder on. What size brake lines will I need?
Tom in Suffolk

I'm doing the same thing. Funky, those are some awesome photos that you laid out. Does anyone know why there are two different sizes on the Nova brake lines? I plan on going 3/16 f-r, but the front are kind of funky, no pun intended, having both sizes. Same as the rear. Any good explanations for this? Dave

I almost forgot. Funky, on your master cylinder pics there is a plastic piece that goes behind the master in the firewall. Did you buy that aftermarket, or is yours just in that good of condition? My fell apart when I took the master off and I'm contemplating just putting a piece of tin in it's place. Damn old cars. But I gotta have it. Dave

I almost forgot. Funky, on your master cylinder pics there is a plastic piece that goes behind the master in the firewall. Did you buy that aftermarket, or is yours just in that good of condition? My fell apart when I took the master off and I'm contemplating just putting a piece of tin in it's place. Damn old cars. But I gotta have it. DaveGood Question. Mine was OK so I ordered a brand new one from (Jeff) NIGHTSHADE on this board. He can order it and send it to you directly. I think I paid just a few bucks. SEND HIM A PM...He'll know exactly what you are talking about.

Dave:D

I'm doing the same thing. Funky, those are some awesome photos that you laid out. Does anyone know why there are two different sizes on the Nova brake lines? I plan on going 3/16 f-r, but the front are kind of funky, no pun intended, having both sizes. Same as the rear. Any good explanations for this? Dave
Compliments from jaynova above. Read Terry's article...it explains it thoroughly.

Scroll down the left hand side to the BRAKE INFO link.

http://www.angelfire.com/nv/conv/

...
'

Thanks for the info. I'll send hm a message. Dave

After reading his article, which was very good, it still didn't answer my question of why there are two sizes of brake line in this system. I know you run a disc/drum deal, and the piston size of the dual is supposed to be the same size for front and rear. Right? If that is so, then why does the master have different size ports? And.........on your car, which is the front port and which is the rear? And does it make a difference? The fittings are larger in the rear, and on a late model dual master, the rear port is the front and the front is the rear. In drag applications, Wilwood explained to me to run the plumbing just the opposite. With the more braking power going to the rear brakes because of the larger tires to assist in the stopping over the smaller fronts. AAAAAAHHHHHHHHHHH......................I'll figure it out. Dave

After reading his article, which was very good, it still didn't answer my question of why there are two sizes of brake line in this system. I know you run a disc/drum deal, and the piston size of the dual is supposed to be the same size for front and rear. Right? If that is so, then why does the master have different size ports? And.........on your car, which is the front port and which is the rear? And does it make a difference? The fittings are larger in the rear, and on a late model dual master, the rear port is the front and the front is the rear. In drag applications, Wilwood explained to me to run the plumbing just the opposite. With the more braking power going to the rear brakes because of the larger tires to assist in the stopping over the smaller fronts. AAAAAAHHHHHHHHHHH......................I'll figure it out. Dave

The front to front brake line for a 66 drum is 1/4" and the front to front brake line for a 67 with discs is 3/16". The only thing I can figure is they wanted a larger diameter front to front line on the 66s because 66s used a single resevoir system and the front to front line had to ALSO feed the rear brakes. UNLIKE a 67 where the front to rear line simply comes off the DUAL master cyl and runs along the drivers floor board. OR____________
You simply do not need the larger diameter line for discs brake set up.

I DO NOT KNOW HOW LARGE THE 67 Manual Drum front to front brake line is. This would probably answer the above question. I would be willing to bet both 67 drum and disc front to front line is 3/16. Which would hold my red theory above true.

As far as the front to rear lines. The only difference was the 66s t-blocked into the passenger side and the 67s run up the driver side floors, through the steering box straight into the rear port of the master cyl. They were BOTH 3/16 regardless.

Also the rear lines are the same for ALL 62-67s.

Note how one of my front to front brake lines is 1/4 and the other is 3/16. The 3/16 front to front brake line was ordered from Classic Industries for a 67 Nova with manual disc option this is my "true" front to front line. The 1/4" line was my original front to front line and I used it to splice into the front to rear 66 line (it happens to be 3/16). NOTE HOW IT DROPS FROM A 1/4 to 3/16 near the passenger t-block (YES...I SCREWED UP BUYING THE WRONG FRONT TO REAR LINE...I should have got a 67 not a 66.:rolleyes: :rolleyes: Also the proportioning valve (which came with the master cyl )outlet for the rear line is only 3/16 (EVEN THOUGH THE REAR LINE FROM THE MASTER CYL to the Proportioning valve is 1/4.

BOTH FITTINGS COMING OFF MY PROPORTIONING VALVE IS 3/16. The front line coming off the master cyl to the prop valve is 3/16. The rear line coming off the master cyl to the prop valve is 1/4 (BUT AGAIN the line coming off the rear outlet of the prop valve is 3/16 (I don't know why they would do this but the did).

On mine it really didn't matter what size lines I ran off the prop valve. I just had to recycle the old front to front line so I could feed my front to rear line.



OK...now look at these pics.
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005111.jpg
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005126.jpg
http://i34.photobucket.com/albums/d115/FunkyNova66/Progress%20Pics/Engine%20compartment/DEC2005130.jpg


I probably just confused you more huh?:eek: lol.:D

Thanks for the pics and the explanation. I love pics. They explain so much and you get to see other members ideas and cars. I have the 1/4 front to front kit from Chevy2Parts, and a dual master for a 67. I'll just run the rear port to the rear, and hook the line lock up to the front. I'll do all MY plumbing in 3/16 to the rear. I just wish GM would leave all the fitting sizes the same. I hate using reducers. If I get lucky, I'll find the correct fitting some place. I know on my dragster I put a Chrysler master on it, and it came with the fittings, both for 3/16, but one was a bigger port. Thanks for all the help. Dave

Thanks for the pics and the explanation. I love pics. They explain so much and you get to see other members ideas and cars. I have the 1/4 front to front kit from Chevy2Parts, and a dual master for a 67. I'll just run the rear port to the rear, and hook the line lock up to the front. I'll do all MY plumbing in 3/16 to the rear. I just wish GM would leave all the fitting sizes the same. I hate using reducers. If I get lucky, I'll find the correct fitting some place. I know on my dragster I put a Chrysler master on it, and it came with the fittings, both for 3/16, but one was a bigger port. Thanks for all the help. Dave
All you will need is "inverted flares". Most parts stores should carry these in those trays in the back. If not, Ace Hardware would have em.

Let me know if you have any more questions.
Dave (<--funkmeister:D )

bump to the top for future researchers.

maybe a good candidate for a sticky or tech save ;)

I have the special size nuts for 3/16 line that will fit any master cylinder without using an adapter. There are 4 different sizes. Regular 3/16 inverted flare is 3/8-24, 1/4 IF is 7/16-20, special sizes: 1/2-20 and 9/16-18. They are a couple of buck each. It looks much cleaner without adapters. The reason they made the connections different sizes is so you can not hook them up backwards.
Tim

Tim, i'm PM'ing you...

i have a problem with an adapter fitting i need. maybe you can help me. i'll send ya the info via PM.


John :D

I'm new at this so if anyone can help it would be great. I have the Fat Man front coil over suspension with the 3rd generation front Camaro brakes with a Lincoln Versailles (Ford 9") rear disk brake setup in the rear. I'm running 3/16" brake lines with a Wilwood proportioning valve to the rear. The master cylinder is a Corvette manual 4W disk. The brakes really suck. Lots of effort and a spongy pedal. The front calipers are metric and I think they might require a quick takeup master cylinder rather than the Corvette style I have now. The problem is the quick takeup master cylinder is not made for a manual setup with rear disks. Any suggestions?