The Stovebolt Site Forums The Shop Area Driveline Uneven braking 1950 1/2 Ton

After sitting for some months, I found that the truck would swerve to the left when braking. Expected to find that the right brake wasn't working so jacked up that side, spun the wheel and had my wife on the pedal. Braking action seemed to be what I expected.- Tried the same on the left and noticed a slight drag. The spin test showed almost instant stop.

Checked the shop manual and am going to follow the steps (as soon as I figure what I can do to make something to work like the J-4707 tool) Some questions-

I believe that the front shoes do the forward braking. The manual isn't too clear here. Are both shoes adjusted at the same time?

Is there something likely to be sticking or not centered. Last time I had the drums off, I saw that the linings were not worn, did the wheel bearings, and put things back together. Brakes were fine until the truck sat for a while.

Any Ideas? Bill Stewart

I go through this after my '37 goes undriven for many months too. The following is the process a buddy offered and I have used. Others may be able to offer help, perhaps better.

Check for brake fluid leaks:
Was or is there any indication of brake fluid below the brake cylinder or on the tire or ground below where the truck has been parked?

Is the master cylinder brake fluid level where it should be? If only low, add fluid.

If the answers are Yes, then try this. (If the master cylinder is dry the process gets more involved.)

Remove the brake drum and check for any type of contamination. If there is any, clean as needed and replace the drum. Fine grit sand paper on the drum and pads has been used. Then retest.

Chances are the leaking brake cylinder will need repair or replacement. But, the above can buy some time. I've got the repair on the '37 maintenance list. As I understand it the rubber used in reproduction cylinders and repair kits is prone to go bad sooner than later.

I don't know what a J-4707 tool is, but my guess is an alternative is and has been used successfully by many.

Good luck.

Hi Sparky,

Thanks for the reply. After reading my post, I should make it clearer that my left brake seems to be working OK but the right is grabbing. The master cylinder was down in fluid, which I topped off, but looking carefully under (Haven't pulled the drums yet-) shows no fluid leaking.

The tool I mentioned is the small prybar looking item which is poked thru the brake backing plate slot to turn the notched wheel on the brake cylinder adjusting screws.

Am trying to get safely driveable to where I can get into the wheel and master cylinders. Can pull drums where I am, but not easily.(small airport in the woods).

Best, Bill

Your small pry bar is called a "Brake Spoon"...

Mike B

These are available at a FLAPS for a few bucks. I've regularly see them at swap meets and if in a jam, a screw driver will work too, but that's not my preferred method.

Any reason why a brake would become grabby? What is next step if master cyl is dry?

At this point, what I'll do is the adjustment in the manual. Question is, do both forward and reverse shoes, or just fwd?

My first car, way back, was a '38 Chev coupe with same engine and running gear.

Bill

I would adjust both shoes.

a brake gets grabby from contamination, whether it is bit of brake fluid seepage, water from condensation and the drums rusted, or something else. You might try moving it a it down the driveway or some other stretch of pavement with the brakes lightly applied. That may get them working ok so you can get to a place that is better suited for working on it. When my wife's 68 Mustang sits for a while (a month or up to 6) one of the front brakes is real grabby, once I drive it for 20 feet or so with the brakes applied a bit, it settles down and is ok again. My father in law had an International pickup that the rear brakes did the same thing. Every time they drove it, they had to drag the brakes slightly for the first 1/2 block or else the rears would lock up when they hit the brakes coming up to a stop sign!

I would suggest to either take it to someone who does brakes for a living, or do some more research on Huck style brakes. There is too much information that you need which we cannot really cover on a website to make you a savvy brake repairman. Chevrolet Truck Shop Manual is a great place to start.
Carl

Totally agree! One really has to put the time in to be proficient at adjusting the Hucks and in my case it seems I have to re-learn the process every time I do my annual brake fluid evacuation and brake adjustment. The whole process seems to take several hours but she's a dd/only vehicle so safety first!

A 1950 1/2 Ton should have Huck brakes. Here is a discussion about a very similar problem on my 38 Master Huck brakes, which are almost identical to the 1/2 Ton. It shows the solution in my case. Brake problem thread on the VCCA The front shoes does most of the work when moving forward. By the way there is an adjustment for each shoe on the wheel cylinder.

Similar problem I had was the bonding was coming loose from the metal.

Everyone who replied to my questions- Thanks Guys. I drove the truck up and down the airport access road while lightly and intermittently applying the brakes. Gradually, after a little light squeaking, the braking became even and normal.
The truck is now in my driveway, where I plan to pull the wheels and inspect the brakes and relube the bearings (wheel and brake internal pivots).
Bill