Interesting valve cover pressure resolution

[texcl]

Lately I've been having excessive pressure in my valve cover making it leak all over (1.5D) I have done compression tests and the engine averaged 350-310 cold and over 400 warm. So I was just not getting it. The block vent tube had very little pressure coming out of it, it all seemed to be in the head. Well as a last resort I took all the emission hoses off to check for obstructions, they were all clear but just to experiment some more I started the car and pulled the hoses one by one, I finally came to the hose that goes from the vacuum pump (power brakes never worked)to the block and pulled it and oil was literally shooting out of the pump, but I relized it releaved all the pressure from the head. So I plugged the pump outlet and checked everything again. There was now no pressure in the valve cover , it actually has sort of a negative positive pulse coming from it, no oil came out of any of the emission hoses like before and the oil leaks stopped. So I figured the pressure was releaved because the hose was disconnected from the vacuum so I plugged it to see what would happen, and I couldn't beleive it, the valve cover still had no pressure. So the bottom line is that the faulty pump was causing the pressure issue. Who would have guessed.

[air-cooled or diesel]

the power brake booster could have been leaking and this goes into the crankcase as extra pressure.
crankcase pressure varies +and-
plug line with a bolt (clean) and hose clamp. you can use rtv too.

[Fatmobile]

Yep, a vacuum pump moves air from the power brakes and into the engine.
If you disconnect it from the brake booster without plugging it,.. it has nothing to restrict it from pumping as much air as it can into the engine.

1.5D eh?
Do you have the extra upgraded hose from the front of the block to the intake?

[texcl]

No it doesn't have the upgraded hose. It was actually connected properly to the engine, I think the oil that it was pumping in was clogging the lines and therefore causing the pressure. Much of the oil made it all the way to the intake, it had so much pressure. these diaphram pumps are for the birds, it will most likely get a vane pump next.

[Fatmobile]

High block pressure will push the seals out.
Check the cam seal and intermediate shaft seal, see if they are pushed out.

You say the power brakes never worked. Why?
I'm wondering how the vacuum pump could pressurize the block if it didn't have a source of air to pull in. Without a source of air it would have nothing to shove into the block.
If you are saying it was pure oil I don't know where all the oil could have come from.
I'm not sure a vane pump would act any different.

[Quantum-man]

On a recent thread I mentoned that I thought it possible for a pump to pressurise the sump.

Your symptoms of poor brake assistance, makes me think there is quite simply a good vaccuum pump doing it's job, when you have a leak in the pump to servo line.

On that vaccuum line there are several little vac offtakes for extras such as a/c or gear change LED
Check for leaks to the atmosphere...

Over here in the UK they were optional and at great cost, so the rows of nipples were capped off.

[texcl]

There is a bunch of servos attached and I'm sure something is leaking or clogged. The vacuum wasnt spitting pure oil, it was mixed with air, definetly some sort of malfunction with the pump. I sold the car (if the guy ever decides to pay) so I'm not going to mess with it any more.