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Re: the H31 brake booster unit is supported by (m)

This is why I asked for the production date here in the US the very very early 88 735's had the hydraulic boost system then they went to vac.

Re: Brake pedal troubles

What year and production date is the car?

the H31 brake booster unit is supported by (m)

the power steering pump. If you turn off the engine, there is no support.
When you turn off the engine, open the Pentosin reservoir, then pump the brake pedal about 20 times till it gets hard, then the Pentosin container will be full, because the brake booster bomp is emptied then.
Get a Bentley Repair Manual for the E32, good investment, nowdays available for abt. 85 $.
See also my website for further tech tips

SHOGUN'S TRICKS AND TIPS FOR THE SEVEN SERIES

Also change every 2 years the brake fluid.Shogun E32 Tech Tips: http://twrite.org/shogunnew/topmenu.html

Brake pedal troubles

I think that I have got a braking problem with my 750i.

Wen the power is turned off, I can push the brake pedal many many times. It never gets hard.

Although this is my first car with the brakebooster system.
My other cars had a very firm/hard brake pedal after step 3 or 4 times on it when the power was off.

Can anybody tell me if this is normal or if it is a problem.
And how can I fix that?

I already replaced the brakemastercilinder.

Thanx for any help!