65 gmc brake problems

[pbluuz]

Am new here, so here goes. I have a '65 gmc half ton 2wd pickup. I've never
had good solid brakes, but have just driven around the problem. I finally got
fed up and decided to fix them. I have good pedal on the first couple of applications, but after about a block or so, solid pedal, but the brakes just
won't stop the truck very well. I have checked all the wheel cylinders, adjusted the brakes, new master cylinder (bench bled). I found one front
wheel cylinder that seems to be leaking, and will replace today. Could the leaking wheel cylinder cause air to get into the system?

[gimmy 64]

yes it could. really you should replace all your wheel cylinders. it is cheap insurance. especially if you are running the stock single master. one cylinder goes out and you will loose all of your fluid and ---no brakes

[Irishbleueyes]

Originally Posted by pbluuz

Am new here, so here goes. I have a '65 gmc half ton 2wd pickup. I've never
had good solid brakes, but have just driven around the problem. I finally got
fed up and decided to fix them. I have good pedal on the first couple of applications, but after about a block or so, solid pedal, but the brakes just
won't stop the truck very well. I have checked all the wheel cylinders, adjusted the brakes, new master cylinder (bench bled). I found one front
wheel cylinder that seems to be leaking, and will replace today. Could the leaking wheel cylinder cause air to get into the system?

Also depends on what brake shoes you got. Some are better than others, noticeable difference.. Plus the new shoes have to arc to the drums which will stop better as they break in..

[pbluuz]

Thanks for the info; I changed the one cylinder in the front and it made a big difference until I got about a block, then the same thing...good pedal but the truck just doesn't stop well. Am intending to install new shoes on the front, as the side with the leaking cylinder might have gotten saturated with brake fluid.

[tincan1966]

Inspect the brake drums while you have them off. If the contact area is real shiny, or "glazed" it will greatly reduce the stopping power because the shoes have nothing to grip.

I'd strongly suggest replacing the shoes, because of the fear of contamination, as you mentioned, but would also have the drums resurfaced if they are still a safe diameter. I'd replace the other front wheel cylinder, too- my opinion is replace them like shocks-only in pairs.
Simply scuffing them with sandpaper will not help much, as they need to be trued up so the new shoes will seat properly.
Doing this will also allow you to repack the front bearing and install new grease seals, which is never a bad idea.
New shoes, resurface drums(or new if yours are not turnable), new seals and packing bearings will be about the best improvement you can do for less than $100 for original brakes.
Don't forget to check and adjust the rear brakes while you're at it.

[pbluuz]

Thanks for the heads up. I did notice some shiny areas on the front shoes, and also that the drums are pretty worn. I'm thinking of just replacing the front drums, as they are not really expensive. The rear shoes have been replaced, along with one of the rear cylinders, which was stuck. I don't drive the truck very often, will obviously have to do so more frequently.

[pbluuz]

Replaced front shoes, and the other front cylinder, which turned out to be leaking as well. I have ordered new front drums, which I will install when they come in. The truck now has pretty good brakes with a softer pedal and no grabbing or pulling to one side. I appreciate all of the information you guys have provided.