hard brake pedal. booster vacuum line problem?

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06-11-2014, 07:12 AM

#11

SloopJohnB@mac.com

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Quote:

Originally Posted by ksebby

Wasn't the valve. I replaced it and the problem wasn't fixed. I also took apart the original one which has two little rubber flaps inside which all seemed in good condition. Apparently, you can blow through this valve in every direction when it is in working order--I could with the old one and the new. I have checked my vacuum lines from the engine to the booster and everything looks good. I also replaced all the hose clamps just for fun. The only place I can see that might have a problem is the booster itself; it doesn't make sense to me and I hate swapping out parts without being sure of what the problem is but that's my next step unless anybody had another idea...

Sorry, I didn't look very hard at that valve…it's a suction jet valve rather than a check valve. It removes crankcase fumes with vacuum while engine is running IIRC. Blowing through it isn't the test…it sucks.

There's another check valve somewhere that isn't working. On my 4.2A6 and the S6 there are at least two vacuum reservoirs, the bright blue things that look kind of like 4 spheres mushed together…find the vacuum lines to/from those reservoirs and follow them back to the engine and check all the check valves along the way if not the reservoirs themselves.

That's all I got on this one other than the potential brake booster diaphragm assembly itself.

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