How to replace a 603 vacuum pump. - PeachParts Mercedes-Benz Forum

Hatterasguy · #1 10-27-2004, 09:00 PM

I don't know if this was ever posted here so I will throw it in. Now first a little backround: The original vacuum pumps on the 1986-87 300SDL/D were a flawed desgin that should have been replaced by now. The original design had exposed bearings that would lodge in the timing chain and destroy the engine if the pump goes south!

I compared the new one and can see how they enclosed the bearings so they can't escape. My local MB dealer said they updated the pump 5 times! A quick way to tell if you have the good one is to look at the cover, if it has 4 screws on it your in good shape you have one of the safe ones. If you see a smooth cover like I did, them replace that pump asap! It will cost you $350 but it is cheaper then a new engine.

I didn't know this a few weeks ago! Thanks to this forum I now know about this potential problem.

Replacing the pump is a pretty simple job now these instructions are for a 300SDL a 300D could be different.

1. I un clipped the plastic fan shroud.

2. Remove the fan it takes a 8mm allen wrench.

3. Take them out and set them aside.

4. Stick a rod/screw driver in the top plastic part of the belt tensioner. Take the tension off of the bolt that holds tension on the spring. Back the bolt out and relax the spring. I took the the top bolt out of the shock too.

5. Remover the belt from the top pulley's and push it down to get it out of your way.

6. Now disconnect the top two vacuum lines from the pump.

7. Remember the pump can be under tension from the large spring inside so remove and losen the bolts evenly. They are 10mm.

8. Once the old pump is off make sure you get the old gasket off and clean everything up.

9. Compare the new and old pumps you will see what I am talking about.

10. Now here is the important part you can not just stick the new pump on, it could be under tension if the "lobe" that causes it to pump is in the right position. I used a breaker bar and a large socket on the crank pulley to turn the engine clock wise until the lobe is out of the way. By doing this the spring in the pump is not compressed. I was afraid of cracking the housing it is just cast aluminum. By doing this their was no tension on the pump as I tightened it.

9. I put some oil on the new pump so it wouldn't start dry.

10. You have to play with the pump and gasket to get them to sit right. The gasket is metal and keeps wanting to fall down.

11. Tighten everything up and reconnect the two vacuum lines.

12. I started the car after I put the belt back on and put a vac guage on the new pump to make sure it was working right. I also listened for any weird sounds and checked for oil leaks. The fan gets in the way leave it off to check the pump.

Thats about it; total cost of oe parts from my local dealer:
$339 for the pump
$10 for the gasket.

It didn't take me to long maybe a little over an hour.

psfred · #2 10-27-2004, 09:06 PM

If the cam is like the ones on the 61x engines, it will be free of tension at TDC.

I need to look at mine, the last thing i need right now is to have the vac pump trash my engine!

Peter

BrierS · #3 10-27-2004, 09:07 PM

Good one. Having replaced mine on the 603 earlier this year I can appreciate your concerns as you completed it. I had thought about removing the fan but didn't. If I do it again I probably will since I believe working around it slowed me down.

cornblatt · #4 10-28-2004, 09:13 PM

I've attempted to attach a photo (I hope it works!) showing the difference between the two types of vacuum pumps. Looking at the old design, you can see how the bearings could potentially escape if the pump failed...

The 'old' one in the photo was taken from the car when it had 199,000 miles on it. It still looked (and worked) perfectly fine, but I thought I'd change it just to be safe after reading about the potential problems it can cause if it breaks.

I found the new Pierburg vacuum pump online for $211.33 with free shipping. Although the vacuum pump gasket is available as a separately orderable item, there's already one included with the pump (so you don't need to order one - I wasted $4.72!!

).

Hatterasguy · #5 10-28-2004, 09:51 PM

My pump had over 240k on it and looked fine. But after having heard of pump's destroying good engines I decided to change it.

cornblatt was that pump for a 603? That was an incredible price!

I could only find them in the $350 dollar range online. So I figured for about the same money I might as well buy the oe one.

cornblatt · #6 10-29-2004, 10:21 AM

Quote:

Originally Posted by Hatterasguy

cornblatt was that pump for a 603? That was an incredible price!

I could only find them in the $350 dollar range online. So I figured for about the same money I might as well buy the oe one.

I happen to have a 601, but the same vacuum pump is used on the 601, 602 and 603. I think it is part # 000 230 31 65. Out of curiosity, I just checked the site where I bought it, and the price has now jumped to $275 (it was $211 five months ago).

Hatterasguy · #7 10-29-2004, 10:34 AM

The dollar is not as strong as it used to be so prices have gone up alot recently.

P.E.Haiges · #8 10-29-2004, 12:55 PM

Do the non dealer parts distributors like fastlane have the up dated pump?

P E H

BrierS · #9 10-29-2004, 12:57 PM

That's where I got mine (FastLane) for my 603.

Hatterasguy · #10 10-29-2004, 06:08 PM

Yeah support Fastlane they have them. I don't think you can get a non updated one anymore, unless someone has very old stock.

jayb79 · #11 10-29-2004, 10:47 PM

This is were i got mine.
http://www.alleurasianautoparts.com/OEMParts/mercedes.wws
$290 free shiping

BTW
My pump worked fine (199k miles) but the sheet metal cover was leaking oil onto the belt and it made a real mess under the hood.

CSchmidt · #12 10-29-2004, 10:51 PM

Hatteras,

Thanks, that is next on my list along with shocks. I've just crossed 270K and still have the original ( I think vacuum pump and shocks!).

Chuck

gsxr · #13 10-30-2004, 03:52 PM

A couple of additional tips:

If the new pump only includes a "dam" or "pocket" gasket, you MUST remove the IP timing basket, if installed. Remove the 3 bolts, pull the little basket out, and save it in case you ever need to remove the IP. If you don't remove it, the dam/pocket hits one of the mounting bolts, and won't let the pump seal against the timing cover - i.e., massive oil leak. The old/original "outline" gasket works with the cover in place. It's rumored that the basket helps contain metal parts should the pump fail, and increases chances of them staying out of the timing chain and oil pump pickup, where then can destroy the engine. So, I prefer to use the 'outline' gasket and leave the basket installed.

The catch is, if you have a very early 603 motor (prior to engine number 000602 for 603.960, and engine 002202 for 603.961 ) you MUST use the dam/pocket gasket to provide enough oil supply to the pump. Most 1986 models will need the dam gasket, most 87-up do not. Details are in this 1.5MB PDF file, on pages 6 and 7:

http://www.w124performance.com/docs/mb/OM60X/OM603_vac_pump_mod.pdf

Final note: Install the coated metal gasket DRY. Clean both surfaces perfectly, and you won't have any leaks. I've done this several times. Never use RTV here, I did once, it took me nearly two hours to fully clean both surfaces - ack! It's just not needed with proper surface prep. :p

Thanks for documenting the procedure, Hattie, nice work!

HTH

Hatterasguy · #14 10-30-2004, 07:20 PM

I put the metal gasket on dry too, I hate gasket sealants. The nice thing about a metal gasket is they don't tend to leak if you don't bother them.

Gsxr I'm not sure what you mean by a basket but the timeing chain is right their you can touch it with your finger. I can see how the bearings would get in their.

turbodiesel · #15 10-30-2004, 08:11 PM

Why are you buying parts at the dealership?? No wonder the car is bleeding you dry! Wholesale price on that Pierburg pump is $251.. list is $314.