Reet, I had a major problem bleeding my brakes, just couldn't get anything out of the rear, no air, no oil, no nowt. Turns out the master cylinder was faulty. Changed it, now i can bleed them, all four corners fine, and one of the bleed points on the ABS unit no probs, bleeds a treat. However, the over nipple on the ABS unit, the one for the rears, i have bled about a litre out of it, and still loads of air, bled it for hours, and still air, something isn't right, with all the nipples closed, it makes a hissy whirry noise, could the ABS unit be faulty and letting air in somewhere? There is no way there could still be air in it, surely? Everything is tight aswell.... Any ideas?

also the pedal goes stiff ish about half way down, but you can just push it all the way down to the bottom...

I was pumping mine for a good 30 minutes on one of the pipes unfortunately matey, it does take ages if there's loads of air in there.

 

I can only recommend a 1 man bleeding kit to speed things up which is what i used to flush the whole system full of oil after sitting dry

cheers mate, i've spent a good few hours on that one ABS nipple, about a litre or more has gone through that alone, maybe it is just loads of air, i finished about 3am, gonna go back to it in a bit, maybe some of the air will have gone to the top, just seems a bit strange! I shall persevere...

I got a one man kit you could borrow bud?

No this is not right, there is an issue somewhere, the brake lines,calipers, abs system and the master cyliner hold a surprisingly small amount of fluid, bleeding the brakes on a zed is no different than any other car of its type and age. I would hazzard a guess that the replacement master cylinder is to blame, most likely drawing air in from the rear seal, so as you try to bleed more and more air enters the system. The fact that you got the four wheel calipers bled could be a red herring as now they are air free the pressure on the cylinder has raised now.

 

A very common problem with the master cylinders is seal flip where cause by pushing the caliper pistons back when changing pads without opening a bleed nipple.

 

Also there can be a problem where the brake pedal free play does not allow the cylinder to return completely, this however tends to cause a different issue but even so it demonstrates why using unprooven cyliders can be a gamble.

 

Try pumping the pedal whilst some one watches the master cylinder resevoir, if little bubbles rise through the fluid you know the unit is goosed.

 

 

Jeff TT

Edited October 20, 201015 yr by JeffTT

thanks jeff.... also, the replacement master cylinder i bought, just didn't seem right, consequently found out that it had been on a shelf for 3 years, great. i stripped it down, and my old one, the seals were hard, and the shape had shrunk, so not many sealing properties, so i replaced them with the nice soft and goodly shaped ones (all the seals are the correct way round etc.) from my old one, which looked in very good nick, it is a strange one this, there is air getting in somewhere, hmmm, got to be the master cylinder then, new seal kit do ya think? although i do think the seals are fine....

i do have about 10mm of free play on the pedal before it engages....

thanks jeff.... also, the replacement master cylinder i bought, just didn't seem right, consequently found out that it had been on a shelf for 3 years, great. i stripped it down, and my old one, the seals were hard, and the shape had shrunk, so not many sealing properties, so i replaced them with the nice soft and goodly shaped ones (all the seals are the correct way round etc.) from my old one, which looked in very good nick, it is a strange one this, there is air getting in somewhere, hmmm, got to be the master cylinder then, new seal kit do ya think? although i do think the seals are fine....

 

Probably worth investing in a new seal kit, majority of the time when you strip down a leaking master cylinder there isnt really a lot to see wear wise.

cheers mate, and your 2000th post too! congrats :)

cheers mate, and your 2000th post too! congrats :)

 

Fook sake never even noticed that, cheers