VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 38 Master Brake Problem

I bought my 38 Master last summer. Among other things that I did to pass the safety check was to rebuild the brakes. The previous owner had completed his rebuild in 1987 so I rebuilt the wheel cylinders, had the master resleeved, replaced the rubber lines, purchased new shoes and put new drums on the rear. the front drums were perfect. All seemed to work well except after a period of time, the right front brake fails to work or provide any stopping power. I reasoned that it must be the wheel cylinder so this winter I replaced it with a new one. Since I had the motor out this winter, I replaced all the hard lines because of the easy access. Well, I took the car out this morning for a short test drive and the brake problem is back. I can make it go away by hammering the brakes hard a few times when just rolling and then they will operated normally.

What should I be looking for as the source of my problem?

maybe a bad wheel cylinder

So it's pulling to the left when you apply the brakes?

Tiny,
that is correct. After I get it to operate properly the problem will return within a day or so.

This is the main reason I switched to silicone brake fluid...it doesn't absorb water, doesn't evaporate easily, and reduces sticking wheel cylinder syndrome.

If it only happens on that one location....I'd check out the 3-way junction block to see if there's any debris inside...

Just a guess but I'd look at the LF not releasing all the way. Could be weak return spring, a piece of crud blocking the port, etc.. Have you pulled the drum on the RF and had someone lightly step on the brakes to make sure the shoes move properly? If the shoes are moving normally it's a sign the issue may be the LF. Just something to look at. Good luck with it. Huck brakes are not my favorite.

The only time I don't like Huck brakes is when the parts go flying when assembling the shoes to the links! This is a weird one and thanks for the comments. Maybe there will be more suggestions.

Tiny has a good point, check the other side. I would take the drums off one side first, have someone gently press the pedal, and watch to see if the shoes spread evenly.

You might have to get in every couple weeks or so and just pump the pedal to keep things lubricated....

Oh, and yeah, I've had to resort to using Vise Clamps, C-clamps, and other homemade contraptions to keep everything in one place while working on those brakes...tell me, has anyone heard you cuss like a sailor while trying to get that extra-strong spring in the little hole?

I work alone when I work on them! So far the walls dont talk.

If springs look OK on inspection sand the glaze off the shoes and drum.
My '39 would do that after winter storage and after sanding every thing was OK.

Have you checked the lines going to that wheel for kinks? There is a lot of hydraulic pressure when applying the brakes and if the there is an obstruction in the line and/or the return spring is weak, there may not be enough return pressure to force the fluid back into the master cylinder thus keeping the brake engaged. This could be exacerbated if there is a very close tolerance between the shoe and drum. When I replaced my shoes, I could not get the rear drums on. Per Chev Nut's recommendation, I had the shoes ground down some and that solved the problem. Beamer

I'd replace the brake hose.

Thanks for the reply. The brake hoses and lines are all new. I am thinking that part of the linkage may be binding.

There can be problems with new parts. It might be prudent to give all the lines a once-over to be sure none of them were bent or kinked in some way during installation. It seems to me you replaced the lines with the motor out. Could you have possibly pinched the line going to that wheel when you reinstalled the motor? Just a thought. Beamer

So I think I found the cause of the problem. The forward shoe on the right front has the bonded material glued on crooked! Because it starts out straight and then curves, part of the edge isn't flush with the metal backing. It is also too far over to the inside of the shoe before it curves and the brake material was also gouged by the rest on the back plate. So the shoe was acting as per Gene's hint but for a different reason.