Oil leak redux - at or around vacuum pump

[slykens]

Hello All! Me again. :(

I've been chasing an oil leak and thought I had it whipped but apparently not. I put the car up on the rack, dropped the belly pan, and got a decent look up the front of the motor. It looks like oil is leaking from the bottom side of my vacuum pump or very nearly there. A wipe of a clean towel on the bottom of the front of the vacuum pump shows small evidence of a fresh oil leak but visually it appeared to be more active from the rear of the vacuum pump. It only leaks after being run and getting hot. Because I park on a slope with the rear elevated the oil is flowing down the front of the motor then exiting from the belly pan in front of the driver's tire. (I put an aluminum pan on it so there's no where for it to pool, it's basically flat under there)

As part of chasing this leak I had done the vacuum pump rebuild kit a couple months ago - when I had the pump off I didn't see any cracks or other physical defects but evidence suggests there has to be one. The day I had the car on the rack we pulled the pump again and tried to make sure it sealed to the crankcase properly.

Is there anything else in this area prone to leak - and especially something that could wick or flow down to the front of the vacuum pump? Should I just buck up and replace the vacuum pump with new to rule it completely out?

Thanks!

[Fresh.S4]

make sure you have the correct gasket!

i had the same leak and replaced with the rkx gasket https://www.rkxtech.com/collections/...it-b8-s4-q7-c6 , because of those 2 notches you see on the inner gasket, it didnt seal correctly. ended up returning it and purchasing a gasket from elring https://www.rockauto.com/en/parts/el...p+gasket,11817 that solved the problem.

[SwankPeRFection]

FYI, the RKX rebuild kit did not work for me and their initial gasket would leak too. I ended up getting a new pump and new gasket and even then I didn’t trust it and put down a small film amount of Hondabond on both sides of the gasket to get a good seal. That said I also had to fix an RTV seal issue on the very edge of the head cover that the vacuum pump plugs into because one corner pulled and pealed out when I took out the original pump and that caused a seam leak there. Again, had to be addressed with Hondabond as well. Wacky assembly from the factory is what it seemed. Issue was similar to a cam seal leak issue on other motors in such corners of the head.

[slykens]

Thanks to both you and Fresh.S4.

When we pulled the pump we did put a thin layer of sealant on the gasket before replacing it but since it's low hanging fruit I ordered a new gasket from the local dealer - not $7 but basically the same price I'd have paid with shipping from Rockauto. Confirmed with them it's the same as the Erling gasket - pink, no notches.

When I pull it next week I'll look closely at that seam you're talking about, Swank, and make sure it doesn't need a little bit of sealant there, too.

Thanks all!

[Fresh.S4]

you shouldnt need sealant...

the elring gasket alone has sealing rings around the gasket. just make sure you clean both surfaces (pump and head).

[slykens]

Well I got the factory gasket, took off the pump, cleaned the surfaces, put the new gasket in and reassembled.

I don’t think that solved my problem. I don’t think it’s the vacuum pump itself as the belt that passes below it is dry - what’s the protrusion directly below the where the vacuum pump meets the block? Looks like something with an Allen key screw in it - wondering if it could be something there.

I suspect I’m destined to pull the pump again, maybe I should get a bore scope so I can get a good close look under where the pump meets the block?

[SwankPeRFection]

That Allen screw needs to be tight. If you take it out, it’ll leak oil. If you accidentally unscrewed that when you were going around finding the bolts for the pump, it’s possible you loosened it up and it’s leaking. You take that Allen bolt out and oil will come out from the head.

[slykens]

That Allen screw needs to be tight. If you take it out, it’ll leak oil. If you accidentally unscrewed that when you were going around finding the bolts for the pump, it’s possible you loosened it up and it’s leaking. You take that Allen bolt out and oil will come out from the head.

I did not (and have not) fool(ed) around with it but I'm wondering if it has worked its way loose and could be the source of my issues. Maybe I'll pull the pump tomorrow morning and see if that Allen screw is in tight.

Thanks!

[sepheroth86]

My vacuum pump had an internal seal that went bad. Caused a pretty significant oil leak.

Replaced pump and gasket solved the problem.

[slykens]

I rebuilt the vacuum pump a couple of months ago.

I think I’ll check the Allen screw and if that doesn’t help I guess a new vacuum pump is next.

Thank you for the help.