The Stovebolt Site Forums The Shop Area Engine Shop More brake woes

Hey all. Thanks for the suggestions on getting a stuck brake drum removed. Heat did the trick.

Now I have the brakes back together with new rear wheel cylinders, one new p-brake cable, speed bleeders at all 4 wheels, and the system flushed and filled with DOT5.

I'm having 2 issues: I still have (maybe) some air in the lines, since after pumping the pedal will go down about an inch or two less than the first push. I would just think I needed to bleed more (Though I've done it repeatedly very carefully) were it not for issue #2. The brakes seem to only be off or on all the way. With the truck moving at walking speed I push the brake pedal slowly and it does nothing until it reaches a point where the brakes engage VERY hard, very suddenly. Any thoughts about what that might be? Are my two issues related?
The truck is a '42 Chevy 3/4-ton Special, if that makes a difference. Thanks for the help
-Jon

Yep...brake shoe adjustment is a huge deal on the Huck brakes.

...did you replace/reline your shoes? Even tho they might look great with a lot of pad on them, they might have absorbed grease/oil. Once saturated, they will grab and never work right. Mine were "new" but after 20+ years of being storage, they were junk. That slime on them from the bearings killed em.

If you don't have a shop manual, pick one up. It outlines the procedure for adjusting..After bleeding a bunch of times, I finally cracked the book. 15 minutes of shoe adjustment fixed me right up. No issues for a year.

To bleed the brakes just open all bleeders and leave them for about 10 to 15 minutes it will bleed its self just be sure to keep the master cylinder topped up.

WHAT?????? V6 JIMMY were did you hear that???? This might work if all your wc were the highest points in the braking system. But I am sorry this is not good advice!

The brake must be bleed by Forcing the Air our with some fluid.

I read a tip about adjusting drum brakes. All you need is a smooth section of concrete and some news paper. Basically what you do is get the truck moving and stop on the news paper. The wheel that stops firts and slids the news paper is adjusted "closer" then the wheel that didn't stop and slid the news paper. Now you will need to decide which wheel you adjust but it will give you a place to start. If this dosen't make sense send me an email and I will try to explain it better.

Good luck.

I just use one of those cheapo self bleeders (a plastic bottle and some tubing)...Start with the wheel farthest from the mc..Just make sure to keep the mc full..Works just fine, and you can do it by yourself, Steve

Would the problem I described indicate that the adjustment is too loose, or too tight?

First check if there is oil, grease, brake fluid etc. on the shoes and/or drums like an earlier reply suggested.

If the shoes and drums are OK, check the size and position of the brake shoes at each wheel because sometimes there are longer and shorter shoes and if I remember correctly the shorter shoes go toward the front of the truck.

These must be in the correct position relative to wheel rotation as they are 'servo' type brakes that help to apply the brakes as the drum rotates which helps to reduces pedal pressure.

If the shoes are not in the correct position, the brakes will 'self apply' when you 'touch' the pedal and act like you describe.

Your brakes are too loose....I also wonder if your shoes might be bad/greasy.

by the way...I think adjustment is turn the W/C until the brake drags just a little, then back off 4 clicks.