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 Now first a little backround: The original vacuum pumps on the 1986-87 300SDL/D were a flawed desgin that should have been replaced by now.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.

sixto · #8 02-15-2007, 08:16 PM

There are two highs and lows on the timer pump drive so if you set a low to coincide with crank TDC you'd always get a low at TDC, right?

You wouldn't try that with only the vacuum pump off unless the number of IP splines is a factor of the number of timer cogs.

Sixto
93 300SD 3.0

sixto · #9 02-16-2007, 02:29 AM

W126 CD manual has section 43-0618. Zero useful info as Dave said. Use the pictures of the gasket to figure out which bolts to remove. They all take a 10mm socket or wrench. The 3 bolts that take a 13mm socket or wrench hold the IP to the block. Don't loosen those.

Sixto
93 300SD 3.0

greasybenz · #10 02-19-2007, 02:56 AM

Ok got the new pump in. But broke some peices along the way...

Well i need a new expansion tank hose, new vacuum line that goes to the pump and the vacuum hose that goes from the pump to the brake booster. The nipple on the check valve broke off as i removed the hose from the old vacuum pump.

neither fastlane or ******** list the check valve but fastlane does list the booster vacuum hose so ill probably just buy the entire hose.

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1ZH1ESC5320R05R2IT&year=1987&make=MB&model=300-DT-002&category=All&part=Booster+Vacuum+Hose

The removal of the serpantine belt was easier then expected, actually it seemed easier to remove then the belts on the 617!

I only removed the fan shroud and radiator to do the job. I left the fan on there as it wasnt in the way of removing the vacuum pump or the belt. The old belt was defenetly past due for a change! the belt was cracking and a good chunk of tread was missing on the belt!

I do have some radiator questions though. When i turned over the radiator to get any excess coolent out some orange goop spilt out. My dad was worried about rusty water. It had the correct MB coolent in there not the green stuff.
My guess was that the orange goop was the anticorrosion additive in the MB coolent?

gsxr · #11 02-19-2007, 11:25 PM

With the right tools, it's much faster to leave the radiator installed, but remove the fan+clutch assembly. And yes, the serpentine belt is fabulous compared to the awful V-belt fiasco on the older engines!!

BTW - that check valve is not available separately. You have to buy the whole Tecalan (plastic) hose assembly with the check valve in the middle. It's brittle after 20 years under the hood anyway, probably a good thing you're replacing it.

Icefire · #12 03-04-2007, 10:31 PM

Hey guys Ive read this thread twice, and I still need help with the vacuum pump gasket issue. Ok I have an early engine, so therefore Im supposed to use the "dam" type gastket which isnt sold individually. my 87 parts engine already has the updated style vacuum pump, so im not going to buy a new pump just to get the "dam" gasket.

Is there any way with the early engine to leave the basket in place, and use the new style gasket.

Does anyone have an extra gasket that they will sell?

Does anyone have the vacuum pump PDF file listed earlier in this thread, the links are dead.

Thanks

psfred · #13 03-04-2007, 10:49 PM

I believe the dam type gasket and the basket occupy the same space, so no, you must remove the basket or use the old style outline gasket.

Peter

ke6dcj · #14 08-21-2007, 11:43 PM

Dave,

I've joined the club. Now to check this and a bunch of other things.

:-) neil

gsxr · #15 08-23-2007, 11:06 AM

Quote:

Originally Posted by ke6dcj

Dave,

I've joined the club. Now to check this and a bunch of other things.

Awesome - congratulations, Neil! And welcome to the club.

Ya know, the last time Neil bought a wagon, it ended up with an AMG motor stuffed under the hood. Makes ya wonder what might happen to the "new" '87...