Bleeding Brakes!!

[Griffinr]

Have just changed the calipers on the front of my S3 and am struggling to get the air out of the brakes. Are there any tricks peculiar to the S I don't know about. I have a pressure bleed kit and never had any problems with other vehicles or when I changed the rear cylinders.

Rob.

[Jonesy07]

Rob,

Having just bled my entire system last night [using the two man system] it took quite a while for the fluid to move the through it, at one point I like you thought there was something wrong, also two attempts to get a firm pedal.

Nigel

[FARKIT]

Did mine with a mate - took several attempts to get them right - lots of fluid and patience!

[Griffinr]

Ok thanks, its not just me then, I'll give it another go tonight. Its probably that slopey valvey thing that sits on top of the footwell that causes the trouble.
Rob.

[Jonesy07]

As always, thank you all for the excellent and informative responses.

Nigel

[Barkychoc]

The calipers are fitted with the bleed nipples at the top aren't they?

[Griffinr]

Barkychoc said:

The calipers are fitted with the bleed nipples at the top aren't they?

Yes thats the logical place for them. Eventually got the brakes working again and MOT passed on Saturday after a minor issue with a split rack gaiter on Friday.
Brake pedal still travels more than it used to but I think the new caliper pistons relax more than the old ones which were very stiff. The master cylinder seals are probably a bit tired as well but have decided to get a new one as it turns out my car has the wrong one fitted.

Rob.

[steve j]

Barkychoc said:

The calipers are fitted with the bleed nipples at the top aren't they?

[GreenV8S]

Sometimes air can get trapped and you may need to unbolt components and tip them over to chase air out of the top.

A technique I find very useful for getting rid of air after a rebuilt is to take a long pipe from the caliper back to the reservoir so I can pump fluid round continuously without having to stop to empty containers or refill reservoirs. Be sure you route the pipe so that it runs upwards away from the calipers, otherwise any air you manage to expel will go straight back into the caliper as soon as you stop pumping.

[phillpot]

[quote=Griffinr] Its probably that slopey valvey thing that sits on top of the footwell that causes the trouble.[quote]

That was the problem when I changed all my pipes, lots of rag around it and just loosen the higher pipe connection (outlet), apply a little pressure with "Eazibleed" and job sorted!