Oil Leak 300 SDL, Any Ideas? - Page 2 - PeachParts Mercedes-Benz Forum

sixto · #16 02-15-2012, 09:13 PM

Does the cover have screws holding it down? The old style pump without screws holding the cover has simple crimps holding on the cover. This is okay when the front seal is supple. Over time, the seal hardens and the crimps loosen. You might be able to fashion a new seal from a big o-ring but keeping the old style pump isn't prudent.

Good point - I don't know if there's supposed to be oil in there or if oil gets in there as internal seals give out. Might be more reason to replace an old style pump.

Sixto
87 300D

gsxr · #17 02-17-2012, 12:28 AM

Quote:

Originally Posted by AUDIBLE

Along the line of this thread, I had an oil leak just like yours, and couldn't tell where it was from. So I just ordered a new front crank seal and a new vacuum pump seal. Replacing the front crank seal made it clear that it hadn't been leaking. Replacing the vacuum pump gasket, I saw that the old one had been leaking. Putting in the new one, I managed to over-torque the bolts and a couple of them snapped off as soon as I started the car. Fixed the problem and torqued them correctly, and used some gasket seal to boot. After all this, the leak is now exactly like it was before I started. It still looks like it's coming from the vacuum pump, but I can see that it's not coming from gasket-sealed seam, but rather looks like it's coming from the metal cover on the front of the pump. Can this be? I didn't think there was any oil in that part of it.

thanks!

Your pump is toast. Replacing it will cure the leak. The torque spec on the bolts is VERY low. If you snapped off bolts, you were way way WAY over torquing them. No sealant is needed on the gasket as long as the pump and timing cover surfaces are clean and dry. Don't forget to only R&R the pump when the timing device cam is on the low side, so the pump is not under major pressure as you unbolt it. But anyway, yes there is oil all throughout the pump, there are two oil jets in the block that spray pressurized oil at the pump mechanism. Very common problem, a new Pierburg or Hella pump will fix it.

AUDIBLE · #18 02-17-2012, 01:01 PM

Thanks for the great info. Didn't realize there was a newer pump.

AUDIBLE · #19 02-17-2012, 03:09 PM

1987 300sdl

So, all of the good people here have made it clear that my oil leak shows that I need a new vacuum pump.

In the interest of not spending $400 on a new pump until I actually HAVE $400 for a new pump, I wanted to try re-sealing the crimped-on front cover. Since there's no rebuild kit for this pump, I'll have to improvise.

Has anyone ever taken one of these covers off? Do you just jam a screwdriver under the crimp points and work it off, or will taking it off tend to destroy it? Any other brilliant ideas?

thanks

sixto · #20 02-17-2012, 04:00 PM

You can remove the front cover and work something like an o-ring into the groove. Hopefully uncrimping and recrimping the cover tabs doesn't weaken them

Sixto
87 300D

Hit Man X · #21 02-20-2012, 08:35 AM

Quote:

Originally Posted by AUDIBLE

1987 300sdl

So, all of the good people here have made it clear that my oil leak shows that I need a new vacuum pump.

In the interest of not spending $400 on a new pump until I actually HAVE $400 for a new pump, I wanted to try re-sealing the crimped-on front cover. Since there's no rebuild kit for this pump, I'll have to improvise.

Has anyone ever taken one of these covers off? Do you just jam a screwdriver under the crimp points and work it off, or will taking it off tend to destroy it? Any other brilliant ideas?

thanks

Look for a good used? Can you weld at all? May be able to just weld that cover to the pump.

sixto · #22 02-20-2012, 01:08 PM

You can weld brass to aluminum?

Sixto
87 300D

daw_two · #23 02-20-2012, 03:51 PM

I've already got a new vacuum pump and need to get this on the car. My used pump is not leaking and could get you by until you get the $$$ to replace. I'm putting it off because I'm planning on replacing the tensioner and probably the serpentine belt at the same time.

Shoot me a PM if you are interested.

sixto · #24 02-20-2012, 03:53 PM

How about JB Weld since the cover never has to come off?

Sixto
87 300D