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I have a 2009 2.0 TSI and replaced the seals on my vaccum pump today because there was a bad oil leak. The job was pretty straightforward and the seal kit included 3 o-rings and the gasket between the pump and the head. Everything seemed to be fine until I pulled up to park and after pushing the brake pedal a couple of times it went hard and the brakes almost didn't work. If I drive off it's fine again after the revs get up a bit but the same thing happens if I pump the pedal at low speed.
I've tried pumping the pedal with the engine off, then hold and start the car and the pedal doesn't go down. I think this suggests a faulty booster but it's a bit of a coincidence! I've checked all the vacuum hoses are secure, the only one I had off is the one at the back of the vacuum pump. I can't see anything out of place and if I get someone to pump the pedal I can't hear any leaks under the bonnet.
Does anyone have any idea what I might have done wrong? I don't think the vacuum pump can go on the wrong way, there's a channel on the camshaft it has to line up to.
When I opened the pump itself to replace the main o-ring there was a small part that dropped off the rotor inside, it wasn't attached with anything, it just slid on the end. I put it back and checked it was the same as the other side. I suspect if this was wrong the pump wouldn't work at all though.
I've tried pumping the pedal with the engine off, then hold and start the car and the pedal doesn't go down. I think this suggests a faulty booster but it's a bit of a coincidence! I've checked all the vacuum hoses are secure, the only one I had off is the one at the back of the vacuum pump. I can't see anything out of place and if I get someone to pump the pedal I can't hear any leaks under the bonnet.
Does anyone have any idea what I might have done wrong? I don't think the vacuum pump can go on the wrong way, there's a channel on the camshaft it has to line up to.
When I opened the pump itself to replace the main o-ring there was a small part that dropped off the rotor inside, it wasn't attached with anything, it just slid on the end. I put it back and checked it was the same as the other side. I suspect if this was wrong the pump wouldn't work at all though.