Since I've had the Sprint I've never been that happy with the feel of the brakes, over the past 3 years I have been slowly fixing/updating/fiddling with bits but its air in the braking system that's driving me bonkers!!
Its a single line early 79 Sprint, I have done the TJ upgrade and has no "load sensing valve" as it was thrown in box when I got the car, I have replaced all the pipe work to the rear, and the rear cylinders look ok.
Rear pipe work is slightly different as suggested by Steve B (Carledo)
I've inspected all the unions and can't see any weeping or feel any moisture, the level in the master cylinder never seems to reduce, but after the car has been standing for a while the peddle feels spongy and has to my mind far to much travel, so I bleed the brakes again!, at this point I must mention when I bleed the front callipers I never see any air coming out so they seem fine, but the back is a different story, first few pumps seem ok, then I get masses of air bubbles for about 8 pumps then it seems ok, but I reckon if I keep going I would see another bout of air coming through.
So how is the air getting in? I would expect a leak somewhere but I can't see anything.
My thoughts have turned to the Master cylinder, I have never touched it..but its old, should I suspect that? When pumping am I pushing air into the system from the master cylinder and it takes a few pumps to get to the back?
Any thoughts?