VCCA Home Forums Thread Like Summary - Excessive brake pedal travel

Me from the UK with the '39 Master Deluxe again guys, the last owner has now told me that the brake pedal travels way down before the brakes operate! He says someone has looked at the brakes (car restoration company here in UK) but there's still too much travel. What should I look at first, master cylinder or wheel cylinders? Or is there something else I should be aware of?

Looks like I've got a fair bit to do when the car arrives next week!!

Adjust the brake shoes.

This is out of the 38 manual. The site doesn't have the 39 manual listed. It should be the same or very similar. I'd strongly recommend buying a service manual. Reprint manuals are available from most vendors.
http://chevy.oldcarmanualproject.com/shop/1938/38csm117.html

Welcome to Chat! That is a very nice looking car. I know you will enjoy it.

You can start your research at the site linked below. Many of us on the VCCA Chat have put together a collection of literature related to the cars we own. It is very important.

Old Online Chevy Manuals

Even if you do not plan to do the work yourself the reference material will help a competent mechanic do it properly.

With respect to adjusting the brakes (which I agree is the second task I would try) you can use the information in the 1938 shop manual on that website. The brake design and service procedures did not change between 1938 and 1939.

Adjusting the brakes is not a difficult task but does take time and attention to detail. You need to equally adjust each shoe in each brake. The one issue you might encounter is whether the adjuster mechanism is stuck. One tip I have is to remove one of the rear wheels and the brake drum. Then you can look at the brake mechanism and understand how the adjuster works.

The first task is to make sure there is adequate brake fluid in the Master Cylinder. There probably is but I always start with that check.

Rusty and the others are right on and I advise you to follow their guidance.

If the adjusters are not stuck you can follow the following procedure. It is the same for each wheel.

a. Access the adjusters through the two slots in the flange. Either use a brake adjusting tool or a suitable length flat-tip screwdriver.

b. Facing each wheel cylinder (front wheel or rear wheel) from rear and looking toward the front of the car, turn the adjuster clock-wise. This expands the rearward shoe toward the drum inner surface.

c. Facing the wheel(s) from the front looking toward the rear of the car, turn the forward adjuster clockwise also. This will expand the forward shoe.

d. Adjust evenly/equally as you reasonably can by only adjusting about 5 adjusting motions at a time shifting from front shoe to rear shoe for each wheel.

e. Alternate tightening until you lock the wheel in place and you can't turn it with arm power. Then back off a but 5 adjustments freeing the wheel to turn, a few adjustments front and rear of the paticular wheel. You should be able to hear the shoes slightly sliding on the drum. That is good enough.

f. Repeat this process until you have all the shoes adjusted. Looking from your perspective when looking at the wheel cylinder (even though you cant see it but know it's there), turning the adjuster counter-clockwise causes the shoes to travel, accordingly, inward away from the drum(s).
braking surface.

Note: With the brake fluid checked, you should have good pedal now. If the adjusters won't turn then you must remove the drum to free them up and do whatever it takes to see that the wheel cylinders are in good adjustable shape.

Note 2: If either rear drum doesn't want to go back on you may need to see whether the linkage from the parking brake cables is not the cause. Make sure the parking brake handle is all the way in, and then at the wheel simply use a bar to move the link that is attached to the cable to its most relaxed position. That will allow the shoes to describe the least circumference. With the shoes in their spring loaded position then you will be better able to get the drum to go back on. This last bit, owing to latent position of the parking brake arm at the wheel may presents itself as a problem on the rear wheels, not the front ones.

Exercise the brakes often. The old Huck system is noted for the wheel cylinder pistons sticking if they are not exercised often. Gene advises using a bit of silicone to help seal the pistons from air which over time causes the adjusters as well as the pistons to stick. Some times so bad that you have to take the cylinder off and using a vise, punch and hammer to get the guts out of the cylinder.

I, too, recommend a shop manual. They can be had through either CoftF or Filling Station. They are well worth the cost.

Good luck with that nice looking 39. Not much was borrowed from the 38 and not much carried over to the 40. Sort of a stand along car.

Best,

Charlie

One more tidbit. When you put the spring on the shoes, run the adjuster anchor bolt out until it is seated on the shoe. Then turn the adjusters. It's much easer and faster if you adjust the shoes whilst the drum is off. Keep sliding the drum on until you expand the shoes to where you can just get the drum on. Them do the final adjustment from the back side of the flange.

I hope this makes sense.

Best,

Charlie