41 67 series locks up left front after brake cylinder replacement

[Lee Ball]

The car was locking up the left front and I replaced the front cylinders and hoses (not shoes) and it still does the same thing.  It doesnt do it immediately after adjustments but continues to get worse. 
I can take it for a ride around the block and it seems ok initially then it will continue to pull harder and harder the the left. 
Can anyone suggest something for me to look at?

[Alan Harris CLC#1513]

Could you have a brake line that is kinked or twisted? Also, it is possible that the brake shoes on that side could be hanging up on the backing plate and not fully returning. Weak return springs or worn backing plate or backing plate just needs cleaning and some grease where the shoes rub against it.

[Michael Petti]

The above suggestions are all valid. I fixed my backing plate with JB Weld.
I also had the same issue on my 60 after a shop did the brakes. Something is preventing the shoes from retracting from the drum. Probably a stuck wheel cylinder or a hose that has collapsed internally. As you drive the brake fluid gets hot and expands and causes excess pressure in your system, hence the lock up and pulling. My new wheel cylinder was bad right out of the box. I wound up honing the heck out of it until I was able to move the pistons with my fingers. It worked. The pulling was a brake hose that had collapsed internally trapping brake fluid, heating it up as I drove and cause in the pull. Replacement solved the problem.
Unfortunately, all these parts today are made in China and the quality is inconsistent.  This site has many posts on that subject. My shop gave up on it. ( I found a new shop) My son and I pulled it apart and found and fixed the problems. Good luck and please tell us what you found.  It will be informative for all of us.

[Lee Ball]

Thanks for the suggestions.  I took the drums off again and looked at everything and all looks ok.  I readjusted front and rear and drove down the road at about 40 and kept my foot lightley on the brakes to break in. It will stop relatively straight when you have the weight of the car pushing with momentum. but when you going slow and try to stop suddenly it will lock up the left.  I've swapped the front drums to see if it was the drum but it didn't make any difference.

I ordered shoes and I will replace (although they look new).  I wonder if the bypass in the master cylinder could be partially plugged?  I ordered a kit for it but don't want tp rempve until I have tried everything else.
 
Lee J Ball
979-255-0321

[Jay Friedman]

Michael Petti mentioned a hose which has collapsed internally as a possibility.  I agree.  A hydraulic brake hose can be bad internally but look perfectly OK on the outside.  I suggest that you install a new hose or all 3 hoses, then bleed the lines.  It's true that most hoses available today are made in China, but I've had them on my '49 for some years with no problems. 

[35-709]

From the first post ---
"The car was locking up the left front and I replaced the front cylinders and hoses (not shoes) and it still does the same thing."

Does indeed, though, sound like a bad hose, maybe a replacement hose is defective.

[toybox]

You might also have a crushed or pluged steel line so I would unhook both front hoses and blow compressed air through them to check for this. The next thing I check is are your rear brakes working? I had a car with graby sometimes locking front brakes once. What I found was the exaust guys had laid the new exaust right on the rear brake hose which melted it in half and sealed it. All I had was front brakes to stop a heavy old car. Tim

[Lee Ball]

I finally found out the problem.  The concentric pin (slot in on the back of the pin) ) was turned towards the secondary shoe.   Once I postioned the slot in the pin (more upright) and retightened the nut the brakes appied pretty well.  I was able to adjust them by using a feeler gauge much like a vintage motor mechanic book I have. 
This was on the left side and I checked the right side and the pin was pretty much in the vertical postion.  The car had not been driven much before and I was fooled for awile since the car braked hard to the left before and after the cylinder replacements.
Thanks for the replies
Lee J Ball

[Jay Friedman]

The '49 shop manual has procedures for doing a "major" brake adjustment by adjusting the concentric pin and measuring lining to drum clearances through a slot in the perimeter of the drum. (Cadillac calls it the "anchor" pin.) Adjusting '41 brakes may be similar. 

Art Gardner and I wrote an article with tips on how to do this on a '49.  If you think it might help, email your email address to me and I'll reply with a copy of the article.  (You can see my email address in the Georgia section of the CLC directory.)