Techical Discussions => General Tech- - BRAKES => Topic started by: Robert Rottman on June 12, 2010, 06:42:44 PM

Title: 41 plymouth brakes
Post by: Robert Rottman on June 12, 2010, 06:42:44 PM
Working on the front brakes on this 41 plymouth I just got a few months ago. They were pulling to the left badly...I do have the shop manual...says I need special tools to make linings concentric with drums...arghhh. There's upper and lower adjustment cams for each drum! Anyone have any experience with these antiques?..These are the pre-bendix brakes...locheeds? Anyway...after pushing down brake pedal now...front drums lock up no matter where I have em adjusted...Also...added Dot 3 fluid to reservoir...wondering if that was a no no manual says add ISO-brake fluid only...Hmmm...too bad I didn't read manual first!(

Any advice would be appreciated.
_popupControl();furyfever2010-06-12 23:44:28
Title: 41 plymouth brakes
Post by: Steve on June 13, 2010, 05:55:03 AM
Locking as in screaming locking?
Pete Harriton and I were messing with a set on a 59 recently.  The locking was all over the place.
Do you have the wheels off now?
Title: 41 plymouth brakes
Post by: Robert Rottman on June 13, 2010, 02:50:12 PM
Steve...I only have the front wheels off right now. I haven't even looked at the rears yet. After I make what I think is a good adjustment, I'll hit the barke pedal and then both front wheels won't release. So in other words...They free wheel before I hit pedal and they're real tight after I hit the brake pedal. Wondering now about my next step: Does the master cylinder have to come out (to rebuild) or is there something else I can try first...
Like I say, I topped the master cylinder off a few weeks ago because it was 1/2 way down....I used Coastal Dot 3....wondering now if that was a bad move...incompatable with old fluid?...maybe it swelled the rubber components inside the master cylinder?
furyfever2010-06-13 19:55:13
Title: 41 plymouth brakes
Post by: Leaburn Patey on June 13, 2010, 04:22:41 PM
Sounds like siezed wheel cylinders to me.
Title: 41 plymouth brakes
Post by: Steve on June 13, 2010, 04:34:03 PM
I don't think so
I think I know what it is, I just want a wheel off first.
Title: 41 plymouth brakes
Post by: Rich on June 13, 2010, 10:28:34 PM
Here is a good page on adjusting those old Lockheed drums: (

I had a '36 Plymouth and a '55 Dodge that both had those brakes, and both were great - rock hard pedals and they stopped straight. I use to adjust them every at every oil change (very easy to do with a small adjustable wrench). I did have trouble similar to the one you are having on the '36 after I changed the master cylinder. The rod that went into the back of the MC piston was too long and wouldn't let the pressure release all the way. I had to adjust the length of the rod, but I don't remember if the rod was adjustable, or if I ground some off...

Title: 41 plymouth brakes
Post by: Robert Rottman on June 14, 2010, 03:57:09 AM
Thanks very much Krautmaster...very good writup on how to take care of these brakes. Unfortunately without that special brake looks very difficult to center up these brake shoes. This is just what I suspected. I wish I didn't mess with the major adjustments (anchors) on the front brakes now. Now that the center is off, who knows where I have 'em adjusted. I bet you there's very few guys out there that are able to service these brakes properly now-a-days. I think I can write this 'ol car off for this summer.
Title: 41 plymouth brakes
Post by: Steve on June 14, 2010, 05:06:54 AM
Do the wheel cylinders look OK?  No seepage or anything?
There's a couple of things I want to check on this first.
1.  Look at the linings and see if they have scores in them, or if they are smooth.  Scoring usually means inferior lining material
2.  Look at all the pivot, slide points on the backing plate.  Are they lubed with white grease, heavy grease or no grease at all? 
Title: 41 plymouth brakes
Post by: Robert Rottman on June 14, 2010, 06:14:14 AM
Thanks Steve, I really appreciate your interest in my problem. You obviously care about others in a very fine way. Thank you ver ymuch...( I'll mess with them again tonight and let you know what I find. I have a feeling I messed up the "center" of the shoes to the drum. The problem is...I don't have the tool that the shop manual refers to....and by the sounds of it...they are a very hard to find item. Ford guys covet them too! Maybe I can improvise with a straightedge and a 12" scale to "re-center" the shoes to the drum. I've been in there enough times now to see that there are no obvious leaks/seepage from the wheel cylinders. Linings have even wear with a lot of "meat" left on them...drums are not too bad that I can deep scoring going on...
Title: 41 plymouth brakes
Post by: Steve on June 14, 2010, 08:01:23 AM
I've never scene the adjusters on a pre 50 car, but I am pretty sure the brakes are the same.  They didn't change much post war until the late 50's.
The key we found on the 59 was poor lubrication on the backing plate.  While it was detailed we used white lith, which wasn't good enough.  Had to go to a heavy grease, like that purple or green stuff.  The lith must have caysed the shoes to stick.  It was driving us nuts.
This was on that 60 Plyme Vert of Steves.  Refered to as "uckin fugly"
Title: 41 plymouth brakes
Post by: Robert Rottman on June 15, 2010, 09:17:12 AM
Steve, I think I got it...after talking with a friend here at work...and he said "well, if you don't have "the tool" that's in the shop manual, come up with something else"....He continued and said "measure the diameter of the drums with a scale (a ruler with fine increments) and then measure out from the center of the spindle to the top of the shoes at several locations to see what you got."  He actually came out to my house at lunchtime today. Now....Since the spindle sits out 3-4" farther than the outer edge of the brake shoes, we used small straight pieces of aluminum barstock clamped onto the top of the brake shoes...we then measured around the radius from the spindle center in several spots and then adjusting the cams accordingly so that there was just under 5" at each measurement location (inside diameter of drums = 10").  I then put the drums back on...and guess what...the front wheels aren't locking any more!! Apparently when the shoes are not concentric with the drum, the wheel cylinders appear to lock in the outward postion...but what's actually happening is that the springs aren't strong enough to pull the shoes back because the shoes become wedged in there...I'll do a finer adjustment tonight....but I'm pretty sure I'm back in business. At least in my case...9 times out of 10....the solution to the problem is always something that I've last messed with/messed up. furyfever2010-06-15 14:21:56
Title: 41 plymouth brakes
Post by: Steve on June 15, 2010, 03:36:25 PM
Are these brand new shoes?
The call for the tool on the 5's too.  But I never used it
Title: 41 plymouth brakes
Post by: Robert Rottman on June 15, 2010, 05:31:56 PM

No, I did not buy new shoes Steve...The shoes on the car have a lot of meat on them yet...The reason I went in there was to adjust...the car pulled to the left when I hit the brakes. I hope to fine tune it here in the next few days. Thanks again, Bob
Title: 41 plymouth brakes
Post by: Brian on June 15, 2010, 06:35:28 PM
You should cruise over to the P15-D24 forum.  Lots of great guys and info there.  With my 48 Desoto on the way I've been absorbing all kinds of info over there.

As for adjusting the shoes, I've heard the new relines are too thick.  Can't remember the proper thickness though.  And for setting the shoes properly I was talking to a fellow who is very knowledgeable in these 40-48-ish Dodge, Plymouth, Chrysler and Desoto's.  He told be to save an old drum, and then cut out a couple "windows".  Then you can rotate and measure your clearances all the way around.

Title: 41 plymouth brakes
Post by: Robert Rottman on June 16, 2010, 03:54:10 AM
Thanks Brian, Very very good advice! I'll get over to that forum...and as a matter of of  the lugbolt threads are stripped out on my left front drum. I'll hopefully find a replacement eventually and then cut windows in that one. That can be my new tool. Excellent advice...Thanks! Bob  Also...Best wishes with your 48 to see it when you get her home!
Title: 41 plymouth brakes
Post by: Marc on June 23, 2010, 02:43:44 PM
second time i have heard this i actually sold a guy a junker drum just to cut windows in. His was a 1936 Plymouth. He called back a week later super happy with it. i am runnin really low on 41 plymouth drums and sold the last one turned for $175 plus shipping.