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Hard pedal- little brake power

7K views 18 replies 8 participants last post by  crash 
#1 ·
I have a 65 ElCamino with manual drum brakes all around. I replaced all shoes and wheel cylinders, rear axle seals which were leaking, adjusted shoes to just drag, bled system 5 times now, and I still have a hard pedal to push and they barely stop the car. I realize I'm spoiled by power brakes, but somethings not right. Any ideas other than converting to power or disc brakes? Thanks, Crash.
 
#3 ·
Usually it is poor quality linings. Just because they are "lifetime" guaranteed doesn't mean they will stop. I use the best Wagner brand only. They are the only ones I have never had trouble with.

Drums need to be turned. OR turned out too large so that......
Shoe radius too small for drum radius. Little lining touching.

Shoes improperly installed.

Wheel cylinders smaller diameter than old ones.
Stock size should be OK. If you were to go to larger cylinders or smaller master cylinder diameter pressure would be multiplied.

You can also sometimes increase the brake pedal leverage ratio.
 
#5 ·
little brake power

Yes the drums were turned, its the original master cylinder, and good quality shoes with 0 miles on them. No problem bleeding them, plenty of fluid and pressure. and bled them in the correct order per factory manual. Still don't want to stop the car.
 
#6 ·
crash said:
Yes the drums were turned, its the original master cylinder, and good quality shoes with 0 miles on them. No problem bleeding them, plenty of fluid and pressure. and bled them in the correct order per factory manual. Still don't want to stop the car.



1) the MC is bad,

2) the shoe material is either a poor quality, (see # 3 note above)

3) the shoe radius is bad. I suggest you check the shoe radius and how much lining is actually touching the drum. I'll bet your under 60% touching.

4) You might also check the three places each shoe rubs on the backing plate to see if those spots are smooth and flat and do not have a groove worn in them. That could be making the shoe bind and not expand. But that usually means swerve and pull.

I would give serious consideration to upgrading to a modern 2 reservoir master cylinder, for safety if nothing else.
 
#12 ·
84 Monte Carlo said:
I've installed brakes on cars for 15 years and on some jobs the car dose not stop good untill you brake them in!thats with power brakes.It would be magnified without power brakes
ditto what I said. Something is wrong.

I can see it now.....

"Now Grandma Jones, you have new brakes but your car won't stop until you get about 100 miles on it......."

Sorry, you can't convince me that poor brakes are the norm.
 
#14 ·
Hard pedal no brakes

I have no idea how they worked before, I bought it when it wasn't running and trailered it home. The axle seals were leaking so I did the seals and replaced everything on all 4 wheels, except the rubber hoses which seem to be in good shape. Now that its running I'd like to be able to stop it. I've done my own brakes since I was a teen, but never had this problem.
Tomorrow I'll pull the drums and see how the shoes are wearing, how much contact there is.
Thanks for all the suggestions.
 
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