How to replace E30 brake master cylinder

[Gotheschu 1]

Hey,

I have 6 days to replace my E30's brake master cylinder as I have bleed the system but the pedal still goes to the floor.

I only have a lil bit of an idea of what the thing im replacing looks like so heaps of pictures and help would be awesome =D

Thanks a lot

[hotwire 352]

Hey Jack, firstly

- are you sure it has been bled properly?

- are you sure you haven't got a crook brake line - swelling?

- if both above are ok - has the master cylinder been confirmed as faulty? It may well be but not necessarilly

With this one - as you sound very unfamilair with, I would seriously advise to contact someone familiar with brakes to takle this one - maybe watch/ask questions to learn.

M/C is straight forward to change - remove two bolts mountiing it to the brake booster & the brake pipes

There is a process to bleeding though.

Also - the brake pipes have 11mm pipe nuts - & these can be a b....h to loosen - easy to bugger them without a good pipe spanner

[Gotheschu 1]

Um they were bleed properly. David said its probably the m/c. Got a parts car from a mate that i can get it off so nothin to lose really. Had a quick look at the lines and didnt see any cracks but ill have to check properly. Thanks for what the 6th time today grant

[Gotheschu 1]

Heath told me to give the brakes a good bleed today before I put in a new master cylinder. So got a friend and bleed the front ( rears are drums and I couldn't find the nipple. Haven't driven it yet but the pedal feels better.

Someone who knows how the brakes should feel is most welcome to come drive it round the block cause I really don't wanna get a scary surprise on the track.

=D

Edited December 29, 2010 by Young Jack

[hotwire 352]

Heath told me to give the brakes a good bleed today before I put in a new master cylinder. So got a friend and bleed the front ( rears are drums and I couldn't find the nipple. Haven't driven it yet but the pedal feels better.

Someone who knows how the brakes should feel is most welcome to come drive it round the block cause I really don't wanna get a scary surprise on the track.

=D

Jack you need to bleed the rear as well.

It will have a bleed screw each side. The bleed screws are into the wheel cylinder on the inside of the backing plate - each side (beside the brake pipe)

If re bleeding the fronts has made a difference - then it is more likely an air problem, so the rears also need doing. Regardless - the fluid needs flushing anyway.

You can eliminate the M/Cyl by crimping all four brake hoses & see if the pedal is hard - if so - the M/Cyl is holding pressure. If pedal sinks - M/Cyl is at fault.

And YES - you need to have reliable brakes for what you are intending - hence my first statement about consulting with someone that knows

[Gotheschu 1]

Jack you need to bleed the rear as well.

It will have a bleed screw each side. The bleed screws are into the wheel cylinder on the inside of the backing plate - each side (beside the brake pipe)

If re bleeding the fronts has made a difference - then it is more likely an air problem, so the rears also need doing. Regardless - the fluid needs flushing anyway.

You can eliminate the M/Cyl by crimping all four brake hoses & see if the pedal is hard - if so - the M/Cyl is holding pressure. If pedal sinks - M/Cyl is at fault.

And YES - you need to have reliable brakes for what you are intending - hence my first statement about consulting with someone that knows

Thanks grant

Did a full flush this afternoon. Except back so will do that in the morning.

Would really like someone to come help me and get them to the proper standard. Everyone is busy and holidaying so getting real hard to find someone and don't wanna hassle anyone =/

Ill get a friend to help me tomorrow but might have to ring a paid mechanic or something.

Ill print this out though and follow it tomorrow.

Thanks =)

Edited December 29, 2010 by Young Jack

[hotwire 352]

Bear in mind Jack - you haven't done a "full flush" - only the front, as the rear fluid is unchanged.

Needs to be bled through the rear circuits to be fully flushed.

[Gotheschu 1]

Bear in mind Jack - you haven't done a "full flush" - only the front, as the rear fluid is unchanged.

Needs to be bled through the rear circuits to be fully flushed.

yea true =) my pro terminology.