Leaking BMC (5.7 VXR)

[Lincsls1]

Hi guys.
My Monaro's brake master cylinder has just started weeping. The leak very much appears to be between the reservoir tank and the main body. I'm assuming there's 2 seals, one at the front, one at the back. Mine's leaking from the front.
Does anyone know if it is possible to get new seals for these PBR units and if so where?
Thanks...

Edited by Lincsls1 on Monday 22 April 16:16

[bigwheel]

Apologies but this might be an opportunity to raise a question about whether there is a larger replacement master cylinder out there. Would this give the Monaro better brakes?

[mfp4073]

bigwheel said:

Apologies but this might be an opportunity to raise a question about whether there is a larger replacement master cylinder out there. Would this give the Monaro better brakes?

That sounds like a good idea, but would a larger master cylinder make the brakes too grabby at low speeds and possibly invoke the ABS early from high speed braking?
I think we need a brake expert on this one.
As for new brake seals, I would try Walkinshaw performance first.

[Lincsls1]

mfp4073 said:

That sounds like a good idea, but would a larger master cylinder make the brakes too grabby at low speeds and possibly invoke the ABS early from high speed braking?
I think we need a brake expert on this one.
As for new brake seals, I would try Walkinshaw performance first.

Good shout for the seals. Cheers.

[stevieturbo]

Seals for the reservoir will probably just be o-rings. Should be easy to source if you take it apart and measure what you need.

[motomk]

The non OEM ones I could find online are Protex and Ultima.The ones below are Holden.

https://www.ebay.com.au/itm/GENUINE-HSV-VY-CLUBSPO...

https://www.ebay.com.au/itm/GENUINE-HOLDEN-VT-VX-V...

Protex have rebuild kits for master Cylinders but I can't access their catalogue at work.

Edited by motomk on Tuesday 23 April 13:38

[Lincsls1]

Figured the whole thing is 15 years old now, so I've bought an entire brand new BMC from Aus rather than messing around trying to source seal kits etc..

[Lincsls1]

Can anyone tell me the correct size of the 2 pipe nuts that leave the BMC please? I'm in danger of arsing this simple task up! I have managed to undo the small one with a 10mm flare nut spanner, but the bigger one isn't budging.
I don't have a flare nut spanner of the correct size,and I'm unsure if its a 1/2" nut or a 15/32" nut! Its definitely not metric.
Thanks!!

[vxkev]

Lincsls1 said:

Can anyone tell me the correct size of the 2 pipe nuts that leave the BMC please? I'm in danger of arsing this simple task up! I have managed to undo the small one with a 10mm flare nut spanner, but the bigger one isn't budging.
I don't have a flare nut spanner of the correct size,and I'm unsure if its a 1/2" nut or a 15/32" nut! Its definitely not metric.
Thanks!!

It will be metric iirc it'll be 13mm, 1/2" =12.7mm I know that the ones from the BMC on the modulator are 13mm because I replaced my brake pipes last week

[Lincsls1]

How strange? My 13mm open spanner is noticeable loose. I'll buy and try a 13mm flare nut spanner.

[vxkev]

Lincsls1 said:

How strange? My 13mm open spanner is noticeable loose. I'll buy and try a 13mm flare nut spanner.

will a 12mm go on it ??

[Lincsls1]

Nope, not a chance....a 1/2" open end is a very, very tight fit, I doubt a 1/2" flare nut spanner would go on, so wondered if it was 15/32" but that's a weird size although they exist.
Will get a 13mm flare nut spanner, I'm sure that'll sort it.