Brake master Cylinder

[Rich Britton]

Hello All!

just to confirm my thought's....... My 1990 340 LE is using brake fluid and petrol in near equal measures but the brakes still work and feal fine soo I iassume the master cylinder in leaking and the brake fluid is being sucked into the engine??

thank you very any comments!

[mac]

Assuming that there are no visible leaks (check inside rear drums as well) then the next suspect would indeed be the master cylinder leaking back into the servo unit.
If the fluid was actually being sucked into the engine in any quantity you would have a very smoky exhaust (especially on overrun) but the servo will take a fair volume (probably as much as a half litre) before any degree of fluid would pass into the engine.

Easy to check - remove the two nut securing the m/cyl. To the servo and there should be enough movement of the pipe work to pull the cyl. forward enough to allow a probe to enter the servo body.

Mac