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41 67 series locks up left front after brake cylinder replacement

Started by Lee Ball, January 27, 2025, 12:20:32 PM

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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

#2
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. 
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."

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.
There is a fine line between "Hobby" and "Mental Illness".  Dave Barry.   I walk that line.
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - now back home as of 9/2024
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2