Brake booster - Vacuum lines before and after TB

[turbski]

you are very right. prob shoulda looked a lil closer

[TobyB]

In a few cars, it hides in the fittings- for example, it can be in the fitting that attaches
the hose to the booster.

But yes, it HAS to have that valve. Otherwise, the reservoir that forms the
'pull' side of the booster will leak out the manifold as soon as you apply the brakes.

t

[IS300E30]

Question about the booster vacuum line setup on my M20.

There appears to be a connection before and after the throttle body, through a Y splitter.

All booster systems I've had experience with only have a single line to vacuum, with a check valve.

Why is the E30 system designed this way?

Sorry to bump an old thread. But, are these hoses that the OP posted supposed to be very hard hoses, as opposed to the flexible hoses on other parts of the car?

Mine is very hard. Not sure if that is how these hoses are supposed to be or if mine just needs to be changed?

[ADEN]

Sorry to bump an old thread. But, are these hoses that the OP posted supposed to be very hard hoses, as opposed to the flexible hoses on other parts of the car?

Mine is very hard. Not sure if that is how these hoses are supposed to be or if mine just needs to be changed?

I tested mine by blowing air throught the boot connection and cover the tb connection with my finger and no air was going throught the system. But i didn't know how the test the lower line

[nando]

Sorry to bump an old thread. But, are these hoses that the OP posted supposed to be very hard hoses, as opposed to the flexible hoses on other parts of the car?

Mine is very hard. Not sure if that is how these hoses are supposed to be or if mine just needs to be changed?

yeah, the new hoses are really stiff. I replaced mine a few years ago, as the fittings were quite loose. If yours are tight and not cracked, I'd probably just leave them alone.