Former VWDieselParts.com Forum

I took the vacuum pump off of the jetta to prepare to prime the oil system after rering. I've taken the pump out of my old caddy a number of times but I don't remember what the drive gear looked like exactly. Is this as worn as it looks or does it start with a kind of hourglass shape? (still spins the pump gears)

AIUI. I had some kind of oil delivery issue in this car that burned up the rings in short order. I think it started with the intermediate shaft pulley breaking (see pic) . By the time I noticed, the pulley was visibly wobbly and the timing belt was getting chewed up from the inside edge. I'm trying to figure out exactly what occurred before I fire up the engine. I took apart and inspected oil pump gears while I was in the crankcase... gears looked fine ... no excessive clearence between gears. Vacuum pump gears were very oily and at a glance, didn't look like it was running dry, and I never lost vac. assist at any point during failure.

Ja, they're made like that.

My vacuum pump shaft has the ovaled out slot in it for the oil pump drive shaft to fit into. Yours (the vacuum pump - not your pully) looks like mine.

thanks guys, I guess the excess space makes it easier to slide the vac pump over the oil pump drive shaft while also mating with the gear on the intermediate shaft?

One more double check then I'll stop thinking about this. Here's the top of the OP drive shaft, Still looking like a good match?

Looks like mine, only mine's slightly less grimy on the outside.

That grime is OEM!! can't buy that stuff
.... thanks

I think have a link to a can of grime you can spray on your engine to make it look like crap,... but I can't find a can of maroon patina for the outside, ha.

Looks like you have the vane style pump. I don't usually see problems with how they mate to the oil pump shaft.
The diaphram style often causes wear problems that shove the vacuum pump shaft upwards.

There is a black seal inside the gear that should be changed to the new green one. Dealership item. It seals around the shaft so oil pressure doesn't bleed around it.

yes, vane pump (thankfully). the black seal looks good and for the time being I'm probably gonna leave it. Is there a high fail rate on this seal?

No it's not like the shaft is spinning in it,.. it's spinning with the shaft.
It can get dry and brittle,.. most people don't even know they it's there so it's never been changed.

vacuum pump looks like all of mine i have come across.

never seen an engine with any fatigue on the im shaft pulley like that. don't know if its even possible because of the key but could somebody of installed that on wrong and jammed it into place? i have seen people do crazier things

i had an incident i cannot explain a few years ago with this style vacuum pump. same pump i had been using just fine on 85 jetta. i put a new seal on the shaft while i had it out, i think new ones are green. i was doing some work to the rabbit and even primed the oil with a 36mm pump.

on that cars first voyage on city streets, just a mile down the road i started to smell smoke and could hear all sorts of squeeling in the engine bay and the dash oil light was going off.

of course i thought nothing was wrong and pulled into a parking lot around the corner off the road. the vacuum pump was siezed solid and the timing belt was screaming. no idea what would have happened at high speed?

anyways i pulled things apart because it freaked me out. put another pump from shelf on the car, same oil pump and have been driving the crap out of it since.

I must admit (with shame) that I was the last one to touch that pulley. I took it off to do the water pump. It was last winter and I needed the car the next day. It was about 1 am and cold and I rushed it... I kept the timing belt in place by using heavy duty zip ties to pull the belt off the intermediate shaft pulley, took it off, did the water pump, put the pulley back on and cut the zip ties, turned the engine by hand and it seemed ok.... Ran for about a thousand miles thinking I pulled off a crafty little shortcut.
I think that in working it past the tight, jerry rigged timing belt, I must have pushed the little woodruff key out of place and it destroyed the pulley eventually. I'm still not sure if that lead to oil delivery problem and piston ring burn out, but its a definite possibility.

That's a bummer. Did you fully pull the engine then and replace the two bearings for the IM shaft? (Another nice thing about Quantums is that you can do both with the engine in the car.)

Fatmobile and others, this new green seal of which you speak; do you mean it fits inside the geared end of the vacuum pump, on the part that sits down onto that oil pump shaft? I need to know where this seal is because I don't think I've ever seen one.

no, I just did the rings, replaced a damaged piston, and of course, head gasket, just cause I had to. There is no measurable (by me) play in the shaft itself, so I'm gonna fire it up and see where I'm at. I left the engine in. I'll post a pic of the rings sometime... extreme wear, some were almost gone

This is the seal in the bottom of the vacuum pump. New ones are green. Viton I believe.

I have only been able to find them at the dealership.