Chry54 Posted May 31 Share Posted May 31 i replaced front wheel cylinders. bled and adjusted. now i have a very low pedal, but it does not go higher when you pump it. bakes work fine, but the pedal is low and your foot can press the brake pedal and gas pedal at the same time.i have done many brake jobs and never had this issue. perhaps someone here can advise. thanks dennis Link to comment Share on other sites More sharing options...
Ronnie Posted May 31 Share Posted May 31 Could you have got a spring(s) or adjuster on wrong causing the pistons in the wheel cylinder to not be pushed back in all the way? Link to comment Share on other sites More sharing options...
ply33 Posted May 31 Share Posted May 31 Shoe adjustment is critical on the Lockheed brakes used by Chrysler. In addition, if the shoe has not be arc'd to match the drum then good shoe adjustment will not be possible. 4 Link to comment Share on other sites More sharing options...
keiser31 Posted May 31 Share Posted May 31 Did you adjust the shoes prior to bleeding the lines? Did you adjust the shoes so that just barely rub on the drums? Did you bleed the wheel cylinders starting with the farthest from the master cylinder and work your way to the nearest? Link to comment Share on other sites More sharing options...
c49er Posted June 2 Share Posted June 2 (edited) The shoe linings need to match fit the drum @ just about 100%. The shoes need to be arc machined to match fit each brake drum diameter accurately. Then the shoes need to be centered/adjusted to touch fit the drums by doing the major and minor adjustments. Special tools are needed to do a proper high/ good feel pedal easily. If you cannot do all this as most shops did back in the day you will have just keep driving the car till the brakes wear the linings in for full contact. The pedal will drop as the linings wear. You will need to do the minor brake adjustment as the shoes/linings wear in. Will require at least a couple thousand miles depending how far off the lining to drum fit is.The above pic shows too large of heel clearance. Will cause low soft pedal. There is almost endless online info on doing these Lockheed brakes on 1955 and back MoPar brakes. Edited June 7 by c49er Spelling (see edit history) 1 Link to comment Share on other sites More sharing options...
Chry54 Posted June 7 Author Share Posted June 7 asking around nobody in the parts store even know what arcing the shoes is. i have the brake tool i bought from Keith B so i set the shoes up with that and the minor adjust has also been done. i have been doing these brake jobs for many years and never had this issue. i did the front brakes but not the rears. maybe i need to bleed the rears also. i do not drive the car alot, so waiting for a few thousand miles on the odometer is annoying. i recently did the minors again but no difference. could the pins in the wheel cylinders be too short, or even the wrong cylinders? does not seem likely. thanks for the help. i will post any success. dennis Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 7 Share Posted June 7 We've never been able to get the brakes right on my wife's 56 Chrysler. Never. Always a soft pedal. Multiple master cylinders, new wheel cylinders, adjusting shoes, whatever. I've given up. We don't drive the car much anymore, which is a shame because it's otherwise our best car. But until I figure out how to do something else like disc brakes or something, it's out of commission. What a shame. I was hoping this thread would have some new insights, but it usually boils down to adjusting the shoes, which don't like to be adjusted. It's a crappy design that needs parts and tools that no longer exist, and even then I'm not convinced they can be made to work properly. I have $1000 cash waiting for anyone who can come and fix these brakes, no questions asked. Link to comment Share on other sites More sharing options...
keiser31 Posted June 7 Share Posted June 7 41 minutes ago, Matt Harwood said: We've never been able to get the brakes right on my wife's 56 Chrysler. Never. Always a soft pedal. Multiple master cylinders, new wheel cylinders, adjusting shoes, whatever. I've given up. We don't drive the car much anymore, which is a shame because it's otherwise our best car. But until I figure out how to do something else like disc brakes or something, it's out of commission. What a shame. I was hoping this thread would have some new insights, but it usually boils down to adjusting the shoes, which don't like to be adjusted. It's a crappy design that needs parts and tools that no longer exist, and even then I'm not convinced they can be made to work properly. I have $1000 cash waiting for anyone who can come and fix these brakes, no questions asked. I sure wish I lived closer to you. 1 Link to comment Share on other sites More sharing options...
c49er Posted June 7 Share Posted June 7 Center plane brakes are much easier to set up than the 1955 and back Lockheed type. Arc fitting the shoes, preferably asbestos oe shoes, good support plates and proper return springs. Proper adjustment of the booster could be necessary too. Center Planes work well when done right. Link to comment Share on other sites More sharing options...
Ronnie Posted June 7 Share Posted June 7 2 hours ago, Matt Harwood said: We've never been able to get the brakes right on my wife's 56 Chrysler. Never. Always a soft pedal. Soft pedal usually means air in the system. Have you tried using a Mityvac hand vacuum pump to pull out air through the bleeder screw before bleeding them the conventional way? (pump up the pedal, hold it down, open the bleeder till the pedal goes to the floor, close bleeder, repeat) I've had good success doing that on hard to bleed brakes. Sometimes it's easier to pull air down from the bottom than it is to push it down from the top. Link to comment Share on other sites More sharing options...
keithb7 Posted June 8 Share Posted June 8 I’ve found an error in the OEM Mopar manuals for the master Cylinder. I too could not get my brakes right. The Motor’s Manual had the proper illustration. I moved the seal, then my brakes worked properly. Notice the valve seat seal in these photos. Missing from the upper photo. Ignore drawn the arrow. 1 Link to comment Share on other sites More sharing options...
c49er Posted June 9 Share Posted June 9 Some MoPar piston cups had the washer molded into the cup...others it's a separate washer. Same with after market kits. Link to comment Share on other sites More sharing options...
Chry54 Posted June 10 Author Share Posted June 10 sorry to hear about Matts issue with his brakes. i have done many brake jobs on these early chryslers and have always got good brakes even when i was ignorant of all the issues with the lockheed system. they did away with this system for good reasons. i have a new master cylinder put on about10 years ago and until i replaced these front wheel cylinders i had no issues. i don't even remember why i replaced them. i think i might replace them again. the pedal is not soft, it just is too low.bleeding does not help. are nos ones available, and would the rubber parts still be good? i am going to check the fluid level in the master today.just reaching. of course the location of it is another chrysler mistake. dennis Link to comment Share on other sites More sharing options...
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