D21 brakes. HELP!!!

[hamboy]

Ok, long story short, the master cylinder failed and was replaced, now I cannot get brake pedal pressure. I have bench bled the M.C. and tried every method of brake bleeding I can find and I still have really poor brakes. I did have the rears working well this morning and average fronts, so re-bled the fronts and now back to sweet F/all.

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Any and all solutions are much appreciated
Cheers
Dan

[Crash bandicoot]

Bleed the shortest lines first. F/R F/L, then bleed to the proportioning valve on the rear axle then to each rear hub.

think of a garden irigation line with spray nozzles along it...the water displaces the air at the closest nozzle to the tap first pushing the air to the last one.

[hamboy]

Yep done that twice and doesn't have a proportioning valve, only a tee on the axle.

[Crash bandicoot]

Yep done that twice and doesn't have a proportioning valve, only a tee on the axle.

the master assembled correctly seals etc? (got to ask these things )

[hamboy]

As far as I know yes, it looked correct coming out of its box

[zed]

Do you have access to an air powered bleeder? Makes the job ten times easier and more likely to get trapped air out. Can also see if you are still getting bubbles out of one line so can check/tighten the nuts until no more leaks.

[derk]

what are you getting out of the bleed nipples mate is it an explosive ejaculation or a premature dribble , is there air coming out as well and bubbles when you leave the nipple open? If you've got a rubber cap on the M/C with a breather vent you can use the duster gun on the compressor to apply a slight positive pressure (only very slight or you'll need to go and have a shower ) into the reservoir to move fluid out to the callipers, don't forget to open a bleed nipple first do one at a time and start with the longest and finish with the closest and make sure you don't run the reservoir dry keep topping it back up, you need to hold the cap on tight with your hand to keep it sealed or it'll keep popping off with the pressure did you check and compare to make sure they gave you the right M/C, piston travel the same and the push rod the correct length have you got a hard or spongy pedal does it stay high or go to the floor?

[hamboy]

derk, that's excellent idea, thanks mate. All bleeders working as they should and the pedal is real spongy now.