Brakes Won't Bleed

[chop]

I replaced the entire brake system in my D19 (new master, wheel cylinder, shoes, lines) but I am having problems getting them to bleed. The shoes are all adjusted and there are no leaks anywhere, I even pulled all the drums off to see if the wheel cylinders were leaking. I had a buddy pump the brakes while I bleed and we probably pumped about 1 1/2 gallon of brake fluid through the system but it seems like it loses pressure somewhere. You can pump the pedal up 3-4 times and it feels great but if you let it sit for a few minutes it goes to the floor when you try to pump it again, at first I thought it was the master so I pulled it apart but everything looks as it should in a new master. Is there some trick to bleeding these brakes?

[chopt50wgn]

Did you bench bleed the master before you put it on?

[Alshere59]

My guess is that it is your brake shoe adjustment. I think what is happening is when you pump the brakes the shoes don't return all the way between pedal pushing and you finally get to a point where you have pressure. After it sits they return and your pressure is gone again. Look at this thread for brake info and notice the tool being used.

 

http://mopar.pairserver.com/p15d24ph_forum/index.php?/page/p15d24/tech/brakes.html

[Don Coatney]

Step one is to make sure the brake shoes are adjusted properly. I suggest you make a inexpensive pressure bleeder from a garden sprayer. Follow the link below for tips on how to do it.

 

http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/

 

 

[Joe Flanagan]

I had this same experience with the brakes on a 56 Chevrolet pickup, which has the same basic hydraulic setup. It turned out to be improperly adjusted brakes. 

[Dodgeb4ya]

Thats a excellent DIY bleeder tool! BUT... Don't pump it up to 50PSI, or even 25. Way too much pressure. If something let go brake fluid would be everywhere. 15lbs is plenty especially for the old MoPars and most any old car or truck. I had a hose burst at 25lbs and the clean up was aweful! Even at 10lbs the system can be easily bled.

Bob

[chop]

I bench bleed the master before I put it in and the shoes seemed pretty well adjusted but I'll pull the drums off and check them again.

[suntennis]

Is the brake pedal linkage adjusted so that when the brake pedal is depressed the pedal moves 1/2 inch to 3/4 inch before the linkage makes contact with the master cylinder? This is what it should be but if out of adjustment, I do not know if it would cause the problem you have.

[_shel_ny]

Pull the drums. Put a clamp on each pair of shoes. See how the pedal feels when you do that. The clamps would simulate perfectly adjusted brake shoes. ( well maybe a bit closed than perfect) Correctly adjusted shoes are centered, and have with about .006 clearance.

[Dodgeb4ya]

Or faster easier yet, just crank the shoes tight against the drums. Should be a high rock hard pedal.

[cozmic]

Not sure if this will help at all but I had huge problems bleeding the brakes on my 55 belvedere after putting about 4 litres of brake fluid through it and still no pedal I tried it this way, back off all the brake shoes (away from the drums) bleed the system as normal then adjust the shoes until the drum is locked then back off each shoe until drum rotates. This worked for me I hope you get thhe brakes sorted.

Charlie

[_shel_ny]

Or faster easier yet, just crank the shoes tight against the drums. Should be a high rock hard pedal.

 

True, but that will change the already properly adjusted brake shoe clearance

[Plymouthy Adams]

as the brakes are adjusted correctly tightening them will reduce the space but will not give him a pedal..his failure is not being able to attain a pedal on bleeding....a brake system will get a firm pedal with brakes a bit out of adjustment..only at a lower level (more travel) as he has the wrong size lines on this car I contend he needs change these to correctly address the problem..I have seen this three times now and suspect this will be example #4

[JIPJOBXX]

I would make up one of those rigs that Don has and use it!!! I had the same problem that your having and I made up one of those brake bleeding units and it solved the problems. Cheap to make and you might even find an old garden pump and bottle at a garage sale??? diffenitly I would make up a pump unit!!!!

[chop]

I went and talked to my neighbor this morning, he's an old gearhead who knows his stuff and he has a pressure bleeder he let me borrow. Hopefully I can get this figured out soon because all I need to do is the brakes and wire up the new harness and it should be a runner.

[chop]

SUCCESS!!! I have brakes now, the combination of the pressure bleeder and fine tuning the brake pedal linkage seemed to have worked. Thanks for all the help guys!

[Plymouthy Adams]

_{good deal....glad it worked out..so it was not quite adjusted right first time around...did you have the Aamco tool?}