Still having brake problems

[Tims74]

Thanks to all who replied to my previous posting regarding my brake problems. I have looked at all the wheel cylinders and they all look good (no sign of leaking). When I pulled the rear drums off, parts literally fell out. This is a result of my 18 year old son having his buddies help him "rebuild" the rear brakes. The trouble I have now is that I am not exactly sure how the rears go together the correct way. Does anyone know where I can find a good diagram that shows how to put them together. I have not messed with drums brakes a whole lot and they are a bit different than the ones on my pickup. Both sides have an emergency brake connection. Any help would be greatly appreciated.

Also, any advice on the quickest and best way to bleed them would be appreciated. When I press the pedal, I cannot get any pressure to build up. Have replaced master cylinder already.

Thanks,
Tim

[the FLYER]

bench bleed the master first... then start from the farthest wheel from the master cylinder and work closer...

right rear, left rear, right front and lastly left front...


i don't have a shot of yer rear brakes, sorry... maybe others will...

[Pauls72]

Left rear
http://i21.photobucket.com/albums/b251/Pauls72/Brakes-Left-Rear.jpg

[skrymir]

Sounds like a matter of bleeding it a bunch. Sometimes the master takes awhile to get primed.

Check the adjustment on the rear brakes if it still pulls different directions.
On those brakes you are supposed to back up and stomp on the brakes to adjust them tighter. Doing that has helped my car a couple of times when it was all stock.

[Bart]

Sorry but I'm stepping in here a little late and I did not see your original post.

If you have replaced you master cylinder, as previously stated you will need to bench bleed it before attempting to bleed out the hydraulics at the wheels. Once you have benched bleed the MC you can then proceed to install it into the vehicle. You need to bleed the wheels in the following order, right rear, left rear, right front, left front. When manually bleeding brakes make sure you pump the pedal smoothly. Fast pumping the pedal can cause airation of the hydraulic fluid and you will need to let the vehicle sit so the air will settle, before bleeding further.


When adjusting the rear brakes, I like to run the adjuster out until shoes just start to lock up the rear brakes (to the point at which it takes about 2 to 3 times the normal effort to turn the drum by hand). Then take a narrow screw driver and push back the adjuster pawl, then bake off the adjuster about 5-6 clicks.

One thing to keep in mind when reinstalling all of the springs on your shoes is to make sure you install the spring that pulls the two shoes into the adjusters properly. one end of the spring is coiled and the other end is straight. The straight side goes on the wheel side of the adjuster. If you put it in backwards the coil side will drag on the adjuster wheel. This is very common mistake that I see people do a lot.

Also there is a difference between the brake shoes. The one with the least amount of braking material goes towards the front of the vehicle. This is known as the primary shoe. The one with the most material goes toward the rear, and this is called the secondary shoe.

Frank

[Tims74]

All good advice. I hope I can get some results soon. Also, I bled the M/C before installing. When I loosen the connections from the M/C to the distribution block, I get a good, solid stream of fluid, I just can't seem to get any pressure built up in the system.

Thanks for the advice.

Tim

[the FLYER]

take out the bleeder screws from the wheel cylinders and confirm the bleed holes are clear, then make sure the holes in the wheel cylinders are clear also... if the passages are blocked which is a common occurance on older vehicles, it'll prevent bleeding as the air can't escape when bleeder's are cracked open...


confirm wheel cylinder bleed passages and bleeders are clear and unclogged...

[Tims74]

Thanks again to everyone for the posts, especially Pauls72 for the picture to follow to put the brakes back together.

Tim

[Philip]

Before adjusting check that shoes are seated against the anchor/pivot point the top. If they are not you will need to back off the parking brake cable where the rear cable attaches to the front cable.

[Tims74]

Okay, I have replaced the master cylinder and I get good squirts of fluid out of the lines running into the distribution block. I have checked the wheel cylinders and they all look good and seem functional. I assembled the rear brakes correctly, after parts fell out when I removed the drums. I also adjusted them. Also, I found out that the two shoes with the most material were both on the passenger side, while the two with the least were both on the driver side.

I still cannot get pressure to build up in the system. I took a length of tubing and fitted it on the bleeder valve and placed the other end in a jar of brake fluid. When I pumped the pedal, I did not get anything, not even air bubbles out of the line. Shouldn't I at least get air bubbles???

Also, in a previous thread someone mentioned "speed bleeders". I went to Advance Auto Parts today and they actually listed a set of them for the car. Of course, I grabbed the only pair they had in stock and rushed home to install them so that I could try to bleed them. Needless to say, they did not fit.

Could the lines or distribution block underneath the master cylinder be clogged with something? When I pump the pedal and watch the m/c, I only see fluid movement in the front chamber. Does this mean there is a blockage somewhere and what would be the best way to narrow down the problem??

Thanks again for all the help.

Tim

[Bart]

I'm assuming that when you say you aren't getting any pressure the pedal is dropping to the floor. If you had a blockage and you are not getting any fluid from the bleeders then the pedal would be firm if your master cylinder was creating pressure. If the pedal is dropping to the floor the fluid is either bypassing the seals in the master cylinder, or the fluid is leaking out somewhere or you still have air in the master cylinder. If your master cylinder is working than the fluid has to go somewhere.

Don't take this the wrong way but this isn't rocket science so don't over think what is going on here. Stick to the basic threory of opperation with brake hydraulics and you will find the problem.

My guess is you are still fighting a problem with the MC or distribution block (proportioning valve) has a blockage.

Frank

[Maxturbo]

Tim. Loosen the brake lines (one at a time) at the exit of the combo valve and see if you have flow there. If not remove the combo valve and replace it as they are not servicable. If so... move to the wheel cylinders and bleed, bleed, bleed.

[Maxturbo]

Just had another thought. Is your M/C to pedal LINKAGE adjusted correctly? If your M/C piston isn't fully returning, then you won't get a proper bore re-filling and stroke of the piston. You should have a small amount of play in the linkage to prevent pre-loading the M/C and causing this. It's adjustable at the pedal arm / clevis attachment point.

[Tims74]

After a lot of effort with the vise grips, I was able to break all of the lines free from the distribution block. All three of them seem to have good squirts of fluid coming from them. If the line is clogged, it would seem to me that the system should build pressure against the blockage. Does that seem logical to you?

I can hear and see the front brakes trying to work, but I can't build up enough pressure to make them work. How long should it take to get fluid to the rear wheels? I replaced a m/c on a 64 pickup as well as all four wheel cylinders and part of a line. When I bled them, it seemed to only take a few pumps to get fluid at the rears.

Thanks again,

Tim

[Maxturbo]

Keep bleeding Timbo. You are almost there. ;)

I'd still check the pedal linkage too.

[the FLYER]

just as a thought... if the system is dry... the air will compress quite a bit and it might seem forever ta bleed... try staying on the right rear wheel and bleed till ya get fluid.

i'm sure yer familiar with bleeding, reading yer posts, so i figger that needs no explanation... once ya get fluid to the farthest distance, the others will get done a lot faster...


i know yer prolly frustrated as heck, but take yer time and don't rush it.


another thought... what do ya think about putting compressed air at the line as it runs back ??? leave all connections tight Except the right rear... open it up and put the hose off the bleeder into the jar ta see if ya have an open (or clogged) line ???


that i think would at least confirm an open or closed line... maybe ???




Johnny (tryin' ta help) ;) :D :D

[Maxturbo]

I guess we never commented on this for you...If the line is clogged, it would seem to me that the system should build pressure against the blockage. Yep! You're correct in your thinking.

Blockage (from debris) is a rare occurance in a closed system like this. I HAVE experienced (in a couple of instances)...crushed or bent hard lines, and (rarely) deteriorated flex hoses, where in both scenarios flow is RESTRICTED but not completely blocked. :(

[69NovaSS]

just as a thought... if the system is dry... the air will compress quite a bit and it might seem forever ta bleed... try staying on the right rear wheel and bleed till ya get fluid.

i'm sure yer familiar with bleeding, reading yer posts, so i figger that needs no explanation... once ya get fluid to the farthest distance, the others will get done a lot faster...

well thats how it should be done in the first place start at the wheel farthest away from the master cylinder (passenger rear) and then when that is bled go to the next farthest wheel(drivers rear) and then go to the next farthest wheel(passenger front) and finally go to the last wheel(drivers front)...this is how it should be done...and of course if you have drained the master cylinder due to system repairs OR installed a new master cylinder it should be bled out first before you try to bleed the other lines...

Just a few thoughts...Good luck:)

[Bart]

Tim

What does your brake pedal feel like?

Is it sinking to the floor when you depress it? If so you either have one of three conditions. An external hydraulic leak which from the sounds of it is probably not the case. You could still have a lot of air in the system or a MC that has an air pocket still in it. Or the MC is bad, even though you have a new one I have replaced hundereds of Master Cylinders in my life and I have gotten new MCs that were bad.

Is the pedal spongy when you depress it? If the pedal is spongy then you have air in the lines. Like Flyer said air is compressable and it will make the pedal feel spongy.

Is it a firm pedal when you depress it? If it is a firm pedal and you are not getting any fluid at the bleeders then yes you have a blockage.

Some things that I have found on 1st gen Novas as they age is a large rust build up in the brake lines that starts to choke them off. You could also have a brake hose that while it looks good on the outside could be coming apart on the inside and causing a restriction.

[Tims74]

The pedal goes all the way to the floor when I press it. I am thinking that there is just a huge amount of air trapped in the system, as I cannot seem to get any firmness built up. The front brakes are trying to work. I can see the front driver's side moving a bit when I press the pedal and I can hear the passenger side trying to work.

I don't think it is the m/c as the old one I took off seemed to work ok when I took it off and pressed the cylinder in it. It squirted fluid a good distance out of both holes. With the new one, I get good squirts out of all three lines coming out of the distribution block underneath the m/c. From there, the fluid just goes to the cylinders.

I am going to have to invest in a one man brake bleeder or use some air to push the fluid through the lines. I am trying to do this by myself for the most part. My wife has tried to help me, but she got tired of it after a few minutes of pumping.

Thanks for all the replies. I will drag her out there tomorrow or I am going to spend the 50 bucks on the vacuum pump to bleed them with. Of course, a vacuum pump can be used for other jobs, too.

I will post back when I get them working.

Tim

[Bart]

A vacuum pump is the best way to bleed, but you should be able to clear this problem by manually bleeding.

If you do manual bleed the system pump the pedal smoothly and slowly like you would normally do when braking. Fast pumping the pedal will only make the fluid airated and foamy.

What I find works really well when dealing with a lot of air is to do what I call the up down method. Crack the right rear bleeder and tell the person at the wheel to depress the pedal. As soon as the pedal hits the floor tell him to yell out down and close the bleeder. When you close bleeder yell up and the person at the wheel should let the pedal up. Repeat this process till you start to get some volume of fluid at the bleeder. You can then go back to a traditional method for manual bleeding by pumping the pedal about four times and then opening the bleeder.