bleeding brakes

[jonn]

not a nova but still a vauxhall! i have a astra coupe with abs and recently fitted new braided stainless brake hoses. the reservoir ended up going dry so air got in the system (big mistake!) with engine off pedal is fine. with engine running pedal is spongy and goes to the floor.

i have spent hours trying to get the air out of them. fitted a new master cylinder and changed abs unit as well.

new master cylinder was bench blead before fitting.
brake calipers are right way with bleed nipples facing up.
full system pressure bleed about 50 times by now!
gravity bleed.
got help from a mate to hold pedal while i open the bleeder and then close when pedal goes to the floor.
activated the abs a good few times to get fluid moving in there.

i jacked the back of the car up about 2 foot thinking it would help any air rise and go to the calipers. good or bad idea?

really not sure what to do next and have spent hours at it now. is it worth buying a vacuum bleeder or what to try next?

[meritlover]

Short out the abs relay and jag the pump. That should pump out air trapped in it.

[jonn]

i will try that if i can find what pins to short out. anyone know what pressure should be in each caliper? going to screw a pressure gauge in calipers and see what they are reading with brake pedal held down. it might give me an idea if one is low so could be air in that brake line then.

[meritlover]

You might have torn the masrer cylinder seals. But its probably just air somewhere

[mowgli]

Pressure bleed. Oh, and make sure the handbrake is on hard.

[jonn]

with handbrake on fully i pressure bleed each caliper and ran about 1 liter of fluid through each one and there is still no difference. i put a pressure gauge on the front calipers and they read about 1100 psi each side. i dont have a fitting yet to read the back ones.

i took off master cylinder to make sure seals did not flip even though its a new one and they are ok. going to bench bleed it again and fit it tomorrow then pressure bleed the system again. never had this much problems with brakes before!