vacuum pump at 300,000 miles - PeachParts Mercedes-Benz Forum

tenmaz · #1 10-09-2008, 05:04 PM

my 87 300sdl just rolled over 300,000 miles. Two days in a row it was blowing alot of smoke at startup, so I ordered some diesel purge. Unfortunately the next day I had no vacuum. I have not had the time yet to pull the pump, but what I have seen from my searches here is I need to rebuild or replace. I would prefer to rebuild, but cannot find a rebuild kit. The cost of a new pump is out of control. Anyone know where to find a rebuild kit ? thanks for any help and advice.

rrgrassi · #2 10-09-2008, 05:09 PM

Do not drive the car until the vacuum pump is repaired or replaced. Click on BUY PARTS at the top of the forum page. You can call either Phil or Roy if you cannot find the kit online.

tenmaz · #3 10-09-2008, 05:26 PM

I have checked with Phil no rebuild kit available. He did mention to test the check valve but didnt know how.

123Guy · #4 10-09-2008, 06:29 PM

Quote:

Originally Posted by tenmaz

I have checked with Phil no rebuild kit available. He did mention to test the check valve but didnt know how.

You check the vacuum valve by removing the metal line from the top of the vacuum pump with a19MM wrench (you will also have to disconnect the clamp on that line at the fuel filter). That line screws into the "valve" Phile is talking about. Shine a flash light down into the valve and if you can see through it, it's bad you're in luck, it's cheaper and easier to fix than rebuilding the pump.
If that's the problem, the valve removes with a 22MM wrench. If that's the problem, let me know and I'll explain how to get all the little parts that fell down inside the pump input when the valve fell apart, out of the pump without removing the pump.

tenmaz · #5 10-09-2008, 06:46 PM

Ill check it tomorrow. I have to do something else right now. Just to make sure though you do mean the check valve is located on the top of the vacuum pump right?

123Guy · #6 10-09-2008, 07:18 PM

Quote:

Originally Posted by tenmaz

Ill check it tomorrow. I have to do something else right now. Just to make sure though you do mean the check valve is located on the top of the vacuum pump right?

Yes, the steel line screws into the top of the valve, which screws into the top of the pump. It doen't look like a valve at all - it almost looks like some sort of male-to-male adapter. When you shine the light into it, you should see something that looks like a piece of black plastic - if the light shines through the valve, it's broken and all the parts are down inside the tunnel that goes into the pump. If' that's the case, I'll go into the leghthy explanation, but simple way to get them out.

Hatterasguy · #7 10-09-2008, 08:43 PM

Is yours the old kind with a smooth cover or the new style?

If its the old style, DO NOT START THE ENGINE! Until you remove it and see if it puked parts into the timing chain cavity. If you think a $300 pump is bad, wait until it trash's a $6k motor!

You can't rebuild 603 pumps, just replace.

BenzB0y · #8 10-13-2008, 08:36 PM

Is it possible if a vacuum pump failed during 1987-90 if would be replaced with the same pump? When did they realize it was a flawed design... My 300SDL has 308,000 and has good stopping besides a warped rotor.. I do feel like alot of pressure being put on the pedal almost like ABS kicking in... the ANTILOCK light comes on. If someone had the pump rebuilt under warranty was it rebuilt original? Could the pump fail on the interstate if you're not even using the brakes? What causes them to fail? How long are most original pumps good for...are there some 300SDL's that won't have vacuum pump failure?

compu_85 · #9 10-13-2008, 08:42 PM

Could someone post pictures of an early pump and late pump, looking at it as it is on the engine?

Thanks!

-Jason

babymog · #10 10-13-2008, 08:43 PM

- Is it possible (that) if a vacuum pump failed during 1987-90 it would be replaced with the same pump?

Yes.

- When did they realize it was a flawed design... My 300SDL has 308,000 and has good stopping besides a warped rotor.. I do feel like alot of pressure being put on the pedal almost like ABS kicking in... the ANTILOCK light comes on. If someone had the pump rebuilt under warranty was it rebuilt original?

Not re-built, replaced.

- Could the pump fail on the interstate if you're not even using the brakes?

Yes.

babymog · #11 10-13-2008, 08:46 PM

On an additional note, I've noticed that my vacuum pump rattles loudly, like a ball in a check valve, above 1800rpm. I think I'll be replacing that tonight, ...

Hatterasguy · #12 10-13-2008, 08:50 PM

Their is a great thread about this in the archives that I made, that you can find if you want.

The short of it is this: If you own a 603 and have the vacuum pump with the smooth cover, the bearings are exposed and your playing with fire. If there are 4 screws on the cover its the updated type and you should be allright.

How to replace a 603 vacuum pump.

85300DT · #13 10-13-2008, 11:23 PM

Tell me about it. I'm borrowing a n/a 300d off a friend while my 300d Turbo is getting the drivetrain swapped into a 380 gasser body. On my way up this weekend, to work on my car, his vacuum pump goes south. Luckily it happened about 3kms from my destination. Nursed the car the last 3 kms. Spent the better part of a day doing a swap from one to another..

compress ignite · #14 10-14-2008, 12:18 AM

OM603: Vacuum pump explosion, bearing intact! Injection Pump Timing device wrecked

GSXR's pictorial of his VP failure.

Picture # 3 is the destroyed Injection Pump Timing Device.

tenmaz · #15 10-14-2008, 12:40 AM

Thankyou for your comments. I just returned from elsewhere!!!! I removed the radiator, so I could see what i might have to deal with. Oil was covering the area. I pulled the pump and was happy to find the gasket was breaking down, almost not existent. The pump looks good. It has the smooth surface exterior, but interior looks like the new style. No apparent damage to anything. I will add photos,which I have not done yet. Any quick tips on how to do this? I want to show the pump + 300,000 mark or deutch.