seal between Master cylinder and Brake booster?

[Aaron from Aus]

I am doing my big brake upgrade and other stuff this weekend,

Just reading up the haynes manual and checking that i have everything i need.

i realised i dont have a Seal for between the Master cylinder and the Brake booster ..should there be one there? I cant find the Part in the ETK and my new master never came with one.

Im assuming there isnt, as i cant remeber seeing one when i took the master of the spare parts car..was a while ago though.

If there is ....a Part number and or dimension would be good, as the week is running out and it will be crucial to get before i start!!

Cheers.

[Shawn D.]

There isn't one, per se. The black plastic fitting in the end of the booster which contacts the M/C has both an O-ring and lip seal, as well as performing the function of holding the spring in. Unless you undo the tamper-resistant bolt underneath the booster, you should not affect these seals when swapping out the M/Cs. I would suggest, though, that you see how the brakes feel with your stock M/C before going with the "upgraded" one.

[Threeshifter]

There was a discussion on the old board about the pros and cons of changing from the stock e28 master cylinder during this upgrade.

[smackmybutter535i]

Haynes? You need a Bentley!

[Aaron from Aus]

[QUOTE="Shawn D."]There isn't one, per se. The black plastic fitting in the end of the booster which contacts the M/C has both an O-ring and lip seal, as well as performing the function of holding the spring in. Unless you undo the tamper-resistant bolt underneath the booster, you should not affect these seals when swapping out the M/Cs. I would suggest, though, that you see how the brakes feel with your stock M/C before going with the "upgraded" one.[/QUOTE]

The master cylinder i have is a 750il Master from Steve Haygood .
SO you think i should just stay with the Current master for a while? (e34 535i brake)
Just do the calipers+rotors etc... and see how it goes?

I was thinking this way too, just seems easier. and do the MC and the Hydraulic brake booster another time. (the hydraulic booster works fine, just leaks a little....i have a full rebuilt one...not just the front seal...but all the internal teflon seals etc..)
only issue i have is that i dont want to go throigh the hassle of doing all the brake fluid agin..as i was going to completly flush the lines..and this would have been easier when i disconnect the MC.