Brake gremlins

I did all four brakes. New calipers, new cylinders, all new hardware, new brake hoses in front. Bleeders are on the top (the right wheels).
I used 2 qts. of fluid flushing the brake lines, all nice and clean now.
Bled all wheels 4 times in sequence, got less and less air out each time until got no air, just clean fluid.

Brakes are hard as a rock when Jeep is OFF.
Pedal goes about 1/4 of the way down when Jeep is ON (running). Then still a tad spongy but work OK.

Do I need to just bleed again, and maybe again, or am I looking at a bigger problem??

Spongy could be air or maybe your rear rubber line is shot and expanding.

I know you adjusted the rears, but thought I should ask anyway. :cheers:

joe_peters said:

I know you adjusted the rears, but thought I should ask anyway. :cheers:

Click to expand...

that would be my guess, too. your pedal dropping when you start the truck is normal, that is vacuum pulling on the diaphragm in the booster and means it is working correctly. hard pedal with the jeep off hints at a good master cylinder as well.

I went ahead and put in a new MC I had...the one I'm working on is the 88 MJ. Yes, I did adjust them but I may need to take it apart again just to see if I got it all right. The new MC didn't change anything.

I hope I'm not having to deal with the height sensing prop valve on the D44

Crap...it's pouring outside...I need a garage!!!

joe_peters said:

Spongy could be air or maybe your rear rubber line is shot and expanding.

I know you adjusted the rears, but thought I should ask anyway. :cheers:

Click to expand...

I also checked that rubber hose on the rear...looks new(ish). It also looks like it's a PART of the splitter. Any insight on that??

ParadiseXJ said:

I also checked that rubber hose on the rear...looks new(ish). It also looks like it's a PART of the splitter. Any insight on that??

Click to expand...

Sorry, I wish I had an MJ to play with.

You should, though, have the height valve.

I do mean to keep the valve. I just want to make sure it isn't an issue when bleeding brakes etc. I have to make a longer/adjustable rod set-up to keep the valve relative to the load as I lift it (3" or so).

Brakes fixed by the way...adjuster was clicked out (didn't seat it right) on one of the shoes

arty:

Delete

I see you intend to keep the load sensing valve... I kept mine too :cheers:

If you need info on the proper line routing when keeping the valve, it's at page 5-52 (at least in the 91 full-line FSM) of the Engine, Chassis & Body volume.

http://www.comancheclub.com/forums/viewtopic.php?f=9&t=17968&p=238880#p238880

Let me know if you need other info on it - including how to set the angle of the load sensing valve properly. Sadly it requires special OEM tools that are probably no longer available, and non serviceable/non reusable bushings that are probably also no longer available, but I have the info.

EDIT: also, did you follow the MJ bleeding procedure? It's somewhere on CC too but I can't find it now. Basically you do a full bleed as usual, then open a front bleeder, smack the pedal to shuttle the emergency bypass valve in the proportioning valve block, then bleed the rears again while the front one is open, then close off the front bleeder and bleed all four in the normal order again.