The Stovebolt Site Forums The Shop Area Driveline Emergency Brake not engaging

In typical fasion I tried to solve a problem by diving in with parts and wrenches without really knowing the problem.

My problem was the emergency brake was not holding my 1940 3/4 ton truck. I have owned the truck for 13 or 14 years and had not done anything to the brakes. So I ordered the cables from inline, Got new wheels cylinders and springs and decided I would look at the drums and linings before ordering parts for the harder to obtain 3/4 ton truck.

Surprisingly it all came apart very easily. The problem is now that I have it all back together the parking/emergency brakes still don't engage. I had the SWMBO operate the brake lever and it moves the internal parts but they don't move the brake pads.

One obvious things is the drums and pads could be too worn down so the adjusters are making the pads already too far apart.

Another thing is the rod that runs between the brake lever (Inside the drum) and the pad could also be execssivly worn.

I have found brake pads and ordered them. I am a little more skidish on the drums.

These are 11 inch drums and some places list the 1/2 ton and 3/4 ton drums together. Anyone have any experience with these parts or some advice on what to check or look for.

Lastly, any one have any 3/4 ton brake parts sitting around? I think I could use new rods that link the brake pad to the parking brake lever inside the drum.

Oh and yes the parking brake cable is adjusted to its absolute shortest length and is brand new.

Thanks,

There is a very specific procedure in the shop manual for ajusting the bolt that holds the lever on the shoe. Have you followed that?

How silly of me! I read the manual and it says to adjust the eccentric bolt to take up the space in the slot. This is exactly what I need to do to make them work. Unfortunately this bolt doesn't turn. I can loosen the nut and move the bolt in and out, but not turn it. I guess I will need to take the shoe off again and get a closer look at the back side.

Any good reason this shouldn't turn?

Thanks!

OK. So I went through and adjusted the brakes, set the emergency brake lever with the eccentric bolt. But the cables are adjusted all the way forward to their shortest length and they barely move the brake pads. If I adjust the wheel cylinders as described in the shop manual by turning them back 4 clicks after getting a slight drag, the emergency brake does not move the shoes enough to engage the drum.

I got these cables from inline tube they are listed as 3/4 ton cables. I see the 1/2 ton cables are only an inch shorter. That doesn't seem to be enough of a difference to fix the problem.

There is virtually no adjustability with everything setup the way it is right now. If the cable stretches there is no way to take up the slack.

Any suggestions?

Thanks,

How about one of these?

Cable adjuster

It sounds to me like they sold you a cable that is the wrong length.

I had the same problem and replaced the cable but that wasn't the problem. Check out this diagram: http://chevy.oldcarmanualproject.com/1929_54chevyparts/04/316.HTM. It turned out that the slot on my 5.150 (extension) was too deep so lever 5.149 would not move it when the brake was applied. I took the extension to a shop and they welded some metal into the slot to make the slot shallower so when the lever was moved (forward) the extension moved the front shoe onto the drum. I hope this makes sense.

Rusty,

You may be on to something. The slot on my lever is worn right past the collar that holds the spring in place. You diagram shows the slot barely half way to that point.

I had cable adjusters on the old brake cables. I bought the new cables thinking the cables had stretched. I guess that was a bad assumption.

Thank you,

Well, I broke out the welder and filled in the slot in the emergency brake rod. I would say I filled the slot about a third of the way from the spring retainer.

That did the trick. Everything lines up, the cables are adjusted about half way through their travel. That leaves about an inch and a half of further tightening, if I need it. Resahping the collar and the slot was easier than I thought. I hope this holds up.

The brakes on the truck were getting pretty scary. Everything replaced: master cylinder, wheel cylinders, shoes, springs and cables.

Now on to the front.

Thanks, you guys are fantastic,