Only stops going backwards!

[neil30076]

98 D1 - After a D90 brake upgrade on front, new discs on back, new proportioning valve ( it was leaking) and a new master cylinder - just because ! - and after two manual bleeds and more than one pressure bleed,
it stops way better in reverse that going forward !
Master cylinder bench bleed, over 3 qts of new fluid through it - pedal is hard at engine off, drops under pressure when running due to brake booster --

Thoughts ?

 

[Racer X]

the bleeder screws on the front calipers... facing up or down?

 

[neil30076]

the bleeder screws on the front calipers... facing up or down?

Up.

 

[Racer X]

OK, good. They're not reversed then.

It sounds as if there's still a bunch of air in the lines, lessening the effectiveness of the front brakes. Failing that, the calipers are totally borked and not flowing any fluid, or you put the brake pads in backwards.

I would continue to bleed the calipers and see what comes of it. And if you do find the brake pads are installed backwards... well, that's best kept to yourself, probably.

 

[fishEH]

Brake pads backwards??? Like putting the backing plate against the rotors?

 

[neil30076]

OK, good. They're not reversed then.

It sounds as if there's still a bunch of air in the lines, lessening the effectiveness of the front brakes. Failing that, the calipers are totally borked and not flowing any fluid, or you put the brake pads in backwards.

I would continue to bleed the calipers and see what comes of it. And if you do find the brake pads are installed backwards... well, that's best kept to yourself, probably.

I did another pressure bleed of the fronts, then took the truck onto gravel and tried hard turn and brake, to kick in the abs, after two tries thing now stops on a dime! Replacing the prop valve bleed down the abs lines - and it seems they never refilled fully - are now!
BTW, it was stopping fine before the prop valve replace, so i know the pads are in the right way around

 

[1MITCH1]

Brake pads backwards??? Like putting the backing plate against the rotors?

I've seen that twice.

 

[bigcheif]

I have seen the proportioning valve piston be off center causing this to happen. More so when a line or hose bust,emptying out the brake fluid in the master cylinder.