The Stovebolt Site Forums The Shop Area Driveline Brake question

The brakes on my 1960 c10 apache stepside are a big disappointment. The drums had been turned , new shoes, when I bought it.Pedal is hard as a rock. No leaks. New master cylinder. I replaced the front shoes with little if any improvement.The primary shoes are on the front of each wheel as they should be.
I have the shoes adjusted per the manual....up snug and backed off 12 clicks. THe individual brakes on each wheel appear to function normally..it just takes an awful heavy foot to stop it. Don't bother telling me that is the nature of manual brakes..I drove them for many years. I had a 58 just like it years ago and the brakes were satisfactory.I would appreciate any ideas?
meansam

If the drums were turned before you bought the truck, could they have been turned too far, leaving little travel of the shoes? Or would the pedal just go almost to the floor before you had enough pressure to stop?

Something bothers me here. I think that you will find that the back shoe does most of the work. The front shoe gets dragged around to push on the back shoe and this is the nature of the "self energizing" design.

Yeah, the brake section of the shop manual talks about the secondary (rear) facings being longer than the primary (front). Ed

have you checked to make sure that the wheel cylinder pistons are free? I have seen non functioning brakes due to frozen/siezed wheel
cylinders, have some one spin the tire (off the ground) and apply the brakes to see if the wheel stops....I have also seen non functioning rear brakes due to a Master Cylinder internal failure.

I have the same truck. I replaced the shoes last year, they work fine. Confident in it stopping. Only thing I see is backing off 12 clicks. My manuel recommends " seven notches" sorry I can,t help but good luck.
Ken

I appreciate all the comments. As for 1958GMCnut's posting, I addressed the individual wheel performance in my original posting..I did exactly as you suggested. The master cylinder only has one output line for brakes so it could not be the problem. The failure you describe could only happen with a later model vehicle which uses a double piston. In this case the front /back separate downstream from the MC. I have seen the single brake flex hose for the rear stop up causing loss of rear brake action, but that has been checked.
I have noticed that the brakes seem to be more sensitive in reverse but can think of no reason for this. I would expect just the opposite.
meansam

I'm not a brake expert but over the years I've heard of similar problems being caused by the shoes being reversed. The smaller shoe is doing all of the work instead of the larger. I hope you get it figured out.

I'm with Tiny. Bendix brakes are a bigger pain in the keester than the old Huck brakes, mainly because if the shoes are in wrong, they don't work worth a darn.

The big ones are the primaries, and they should be in the aft posisition on each wheel.

What brand new shoes did you use ? I know that different brands have different " gripping power " and are stamped with a letter on each shoe.If your pedal is " hard as a rock " as you stated , you could have shoes that are too hard. Vintage truck magazine had an article on this subject a few months back. I will see if I can find it.

Did you check all the rubber flex likes for colapse?I had that prob on my 68 and its hard to detect.when you bleed the lines do you get equal pressure from all lines?Another thing to check is all the hard lines for a pinch do to jacking or vandalism..had that happen too,someone reached up under the truck and with pliers crushed the line..(jelousy i think)Also im not sure if you have an equalizing valve to add more pressure to the fronts but they can jam in either direction causing bad braking..hope this can help ya
James

All excellent suggestions. I'd also add this: do you have the right bore in the master cylinder? I've found there are two different bores for the master/clutch cylinder: 1-inch, and 1 1/16-inch.

It also seems like backing off the star wheel a full 12-clicks is a huge amount. I've never done brakes with a shop manual, but what I always do is adjust them out until they juuuuuust drag a little bit when I spin the drum. The first couple of miles will clean them up, and then when I hit the brakes, there's very little travel before shoe meets drum.

Also, I'm my next brake job away from offering Self Adjust drum brake kits for '60-'66 C-10s. I've found all the parts needed, and am working on pricing. I just ordered a full set of new shoes, and when I swap them on, I'll be taking pictures for a tech article and instructions. I've always thought the biggest problem with vintage 4-wheel drum brakes is that they rely on us getting under the truck and adjusting them every 2000 miles. Who does that?! I certainly don't.

-Brad

It is possible that the shoes are not in full contact with the drum due to the turning. I would check the shoes to see it they are showing a small contact patch.

It used to be standard practice to 'arc grind' shoes to match the diameter of newly turned drums. I haven't seen this done in a long time. If this seems to be the problem, you have some choices:

Live with it until the shoes finally wear in, just normal wear will eventually fit them into the drum.
OR
Search out a shop with the correct machine to do the fitting.

The shoe with the small lining is called the primary & goes on the forward position. What about the master cyl. pushrod adjustment. It should have a small amount of free play before pushing in the piston. What about the rear brakes. They could have old hard linings & bad wheel cyls. You didn,t mention the front cyls. You must rebuild or replace wheel cyls. any time you reline drum brakes. Is the new master cyl. the right bore for the truck? A larger bore master cyl. will give tighter brakes but take more pedal pessure. I like to adjust them to a heavy drag & back off about 4-5 notches. It could be like the previous bolter said. Some linings are hard & take more pressure, especially now they are taking asbesto,s out of them.

I have the 1960 c10 stepside also . I my brake shoes are the same size front rear . Front rear all the same. Maybe your shoes are wrong?

On the brakes,,,I think more info is needed on what was done...doc

could be your shoes just need to be broken in by a hundered miles of driving and braking i would replace rubber lines if not done already and make sure cylinders are not froze up

I solved my brake problem. The wheel cylinders were so corroded apparently each wheel had at least one frozen piston. This allowed each wheel to indicate the brake was working when the wheel was in the air. After installing new rear cylinders and kits in the front wheels I now have good braking action.Thanks for all your comments.
meansam