OT. 35 ply PJ Brakes

Hello to all; I tried to find a Ply. web site, but no luck. So here goes: 2 yrs ago we hauled a 40 JD (ok there's the tractor part!) and a 35 Ply home from Ca. Redid all the brakes...new lines,hoses, nos wheel cly,and shoes.I rebuilt the master cly. I don't have brakes till I pump the pedal 8/10 times. Then, grt brakes. We have bled and bled a gallon of fluid.......when the brakes pump up and you hold them, they wolk grt. You let off, and then you count to 10, and they go to the floor again. Then, 8 or so pumps and they work. I just ck'd the two holes in the master, and they are open. I have down a LOT of old cars etc in the past....but, I'm missing something. Any ideas to try or fix? Thanks Bobmn

Do you have the 'cam' brake adjusters? If they aren't nearly equal, meaning that the shoes are the same distance from front and back of the drum, they'll act that way. That's one reason automakers went with the single adjuster at the bottom of the shoes. When the brakes are applied, they'll automatically center themselves.

Id bet money that the master cylinder is bad, mother in laws car was doing the same kinda thing this winter, even the big wigs at GM had to scratch there heads cause they had never heard of em doing that before, but they started changing parts on it to fix it, the first thing to change was the master cylinder cause the pads were new, and the prob went away! Good luck on your quest...Bob

Have you adjusted the brakes?

is that a1935 plymouth if so you have lockheed brakes on it there a can adjuster for each shoe they are nasty to adjust start by turning the adjuster away from the top of the backing plate till the shoe stops the wheel frof turining then bump it back very lihgly till you can turn the wheel and hear the brake draging then do the outher cam on the same wheel the sane way
do all 4 wheels..
when you put new shoes on did you take the pivot bolts out they have an excentric cnthen by the head thats moves the bottom of the shoes out to get the heel of the ashoe clocer to yhe drum the end of the bolt has a mark on it the marks shuld be near to each outher see if you can find an old chilton book they will help a lot or an old mecanice probley in his 80ds.
old art

I also agree it is adjustment, not air. The mechanical parts are not centered in the drums and thus using fluid to get there. if you have driven it (don't) the wear pattern on the shoes will tell a story of where the system is out of spec.
If the shoes are not arced to the drums this may also affect the feel and pedal pumping. Jim

Thanks for the fast answers!! Yes, it has the Lockheed Brakes! Ply. had a gauge to adjust the shoes, BEFORE you put the drums on. I used the drum to ck these. But, now that I think about it, I'm not sure I ck'd them AFTER I put them back on! I will run the car back up on the lift, and ck the adjustment again. Also, will ck out the master cly. again. I'm going to be looking in my old books, also just in case! Turned 70 this yr...and this gittin' old,ain't fer sissys!!!!!! Thanks again,BobMn I'll post back when I find some thing!

Google for Mopar forums or Chrysler forums, there"ll be Plymouths in there somewhere.
aaca and prewar cars.com should have Chrysler Cptn and/or Plymouth forums. good luck.

There are two adjustmetn cams per wheel on the Lockheed brakes. Sounds like they are not adjsuted and the brakes are retracting fully instead of being stopped by the cams. They will be the hex heads on the back side of each backing plate. To lessen the clearance between shoe and drum, what you need to do, turn them in the same direction as the wheel would turn going forward. You should be able to lock the drum. Back off until a very slight drag is felt. Do this on all 8 adjusters. If the anchor pins are our of whack, then you really need the proper brake gage which is rare and expensive. The old Motor"s manuals give a method where you cut a slot in the anchor pins to allow adjustment from the back with the drum on. The gage measures each drum and then fits on the spindle or axle to allow the shoes to be adjusted without the drum in place so you can turn the anchor pins.
When adjusted right, these cars stop really good, unlike most cars with fron drum brakes.
Maybe an old time shop in your area has the gage. I got the Ammco tool off eBay, but not without parting with a lot of $$$. I think it is necessary when you have three cars with these brakes, and two of them are daily drivers.
Could also be master cylinder residual presure valve. Had taht with my Desoto, but the pedel would not go to the floor if the cams were adjusted right. Email me if you need to. Most guys work off memories of long ago, while I still drive these cars every day. "48 DeSoto, "50 Dodge, and "56 Plymouth. I can email you a PDF from a later service manual, same brakes.

Josh

Make sure someone has not turned the drums and taken too much material off. Dad bought a new ford pickup in 1951, had trouble with the brakes from day 1. Dealer kept turning the drums. To get the brakes to work we had to take the shoes and get extra thick linings put on them.

Hello to all! The PJ HAS BRAKES!!! IT WAS ADJUSTMENT!! We had the PJ stored over the winter, and I did this work last yr........Well when I got under to ck, I had never adjusted the brakes!! I never even had the cotter pins in the frt lower adjustments!! AND I found my 1935 shop manual!! I want to thank all for the GREAT answers! As a side note, I'm also doing the brakes on our 630 JD veggie tractor. Boy, are this easy to work on and to adjust!! Also took the tires off and had the rims sandblasted. (42") Trying to get it done for a Fathers Day tractor ride. Thanks again Bobmn

Very good. The adjustment of some shoe brakes is an art. Jim