Brake Problems

I installed a disc brake setup on my 66 and am having a problem with them.When i apply the brake and i come to a stop ,it almost feels as if the rear brakes (Drum) are applying more pressure than the front.I have good brake peddle pressure.Any ideas what could be causing this problem?

Greetings,

I'd look at the proportioning valve...is it adjustable? If so, how is it adjusted? Check the lines...leaking at all? Did you get all the air out of the lines and master cylinder? Just some ideas for you.

Jason

drums hold better than disc.
but disks stop better. or at least thats what ive always been told

Greetings,

I'd look at the proportioning valve...is it adjustable? If so, how is it adjusted? Check the lines...leaking at all? Did you get all the air out of the lines and master cylinder? Just some ideas for you.

Jason

Jason the setup i have came from Master Power Brakes and is has the non-adjustable proportioning valve.I don't see any leaks, but the air in the line is possible ,as i only bled them once and might not have gotten all the air out.
could it be possible that i might have the rear brakes adjusted a little to tight and they are being applied first?

Jason the setup i have came from Master Power Brakes and is has the non-adjustable proportioning valve.I don't see any leaks, but the air in the line is possible ,as i only bled them once and might not have gotten all the air out.
could it be possible that i might have the rear brakes adjusted a little to tight and they are being applied first?


Did you keep your stock Mater cylinder?

If so, this is the problem.

I have MPB system and had problems also, it was the master cylinder they gave me!
Exchanged it and wamo!

I finally went 4 wheel disc. ( and had to change MC again!)

Al

Did you keep your stock Mater cylinder?

If so, this is the problem.

I have MPB system and had problems also, it was the master cylinder they gave me!
Exchanged it and wamo!

I finally went 4 wheel disc. ( and had to change MC again!)

Al

it is one of their master cylinders.

it is one of their master cylinders.

Contact them.

They know there stuff.

I installed a disc brake setup on my 66 and am having a problem with them.When i apply the brake and i come to a stop ,it almost feels as if the rear brakes (Drum) are applying more pressure than the front.I have good brake peddle pressure.Any ideas what could be causing this problem?

What's the problem? You apply the brakes, the car stops, you have good brake pedal feel.

drums hold better than disc.
but disks stop better. or at least thats what ive always been told

I would like to hear a little more in depth explanation of this theory. Anyone have some way of explaining it in terms I can understand.

I would like to hear a little more in depth explanation of this theory. Anyone have some way of explaining it in terms I can understand.

My best guess would be disc brakes dissipate heat better but when cold and locked down the area of shoe to disc would be better on the shoe.:rolleyes::rolleyes:




:cool:

What's the problem? You apply the brakes, the car stops, you have good brake pedal feel.

Something is just not right.It feel like the rear brakes are grabbing first or appling more pressure than front.

Greetings,

I'd look at the proportioning valve...is it adjustable? If so, how is it adjusted? Check the lines...leaking at all? Did you get all the air out of the lines and master cylinder? Just some ideas for you.

Jason
Jason i called the tech at MP and they said it could possibly be the proportioning valve,but said to make sure there is no brake fluid or differential fluid on brake shoes.Haven't checked this yet,but you might be right on with your theory.Thanks

The drums in the back are supposed to engage first (with a metering valve in place).

Which wheels lock up first in a panic stop?

My best guess would be disc brakes dissipate heat better but when cold and locked down the area of shoe to disc would be better on the shoe.:rolleyes::rolleyes:

:cool:

This is pretty much what I've heard as well...but not factual evidence to back it up.

Drum brake shoes have more contact area against the drum than disc brake pads do to the rotor. So at a stop, they have better holding power.

However, drum brake shoes and their contact areas are within the drum and do not get good air flow to cool them down...whereas disc brakes have both the pads and the discs open to ambient air to help cool them down. Better heat dissipation means better stopping.

Again, it's just hearsay from various sources...not factual--so take it with a grain of salt.

This is pretty much what I've heard as well...but not factual evidence to back it up.

Drum brake shoes have more contact area against the drum than disc brake pads do to the rotor. So at a stop, they have better holding power.

However, drum brake shoes and their contact areas are within the drum and do not get good air flow to cool them down...whereas disc brakes have both the pads and the discs open to ambient air to help cool them down. Better heat dissipation means better stopping.

Again, it's just hearsay from various sources...not factual--so take it with a grain of salt.

FACT: The main reasons disc brakes are used rather than drum brakes is because there is less brake fade from better heat dissipation, along with better braking characteristics in inclimate weather conditions.

You guys are on top of your game!:cool:

I would like to hear a little more in depth explanation of this theory. Anyone have some way of explaining it in terms I can understand.

disk brakes work by applying pressure to a surface by means of clamping a springing disk, pinch a quarter between to fingers and try to stop it while turning it with the other hand. you can slow it down but not stop it completely. same is true for the front brakes. as 70% of your stopping power is with the front brakes.

now for the rear. a cylinder which is what a drum is with two arc segments applying pressure to the surface of the drum. as pressure increases the friction can build to the point of making the drum a ellipses and no longer round so it can not turn any more. if you were to apply enough pressure to the drum you could feasibly split the drum. while the disk is virtually non compressible and will not distort like the drum will.

along with better braking characteristics in inclimate weather conditions.

Inclement. Comes from the Latin clemens meaning gentle or merciful.

the early novas use a "servo action drum" setup.this means the smaller front primary shoe,wedges the larger rear secondary shoe into the drum.this gives a "leverage" effect!!!This increases stopping power without any additional effort by the driver because the rotation of the drum drags the shoes around with it, increasing the force holding them together hence the term servo action.

for this drum brake design, an operator can only control his braking to .1....2....3....to around 7 out of 10..then LOCKUP!!!!


front disc give the operator more control over there stopping ability......an operator can for instance brake to the threshold of just before lockup.along with better heat dissipation.

So you're saying you've got drum brakes in bed and your wife was hoping for discs?

Inclement. Comes from the Latin clemens meaning gentle or merciful.

Check your eyes Mike- I spelled it correctly!!! ;):D

Getting back to the original post. If you press hard enough to lock up the wheels and the fronts lock just before the rears. You don't have a problem. It's hard to describe but if the rears are getting too much braking they will lock fast. Then you loop it.:eek:




:rolleyes: