SLS Pump Leak (Unusual) - PeachParts Mercedes-Benz Forum

libbybapa · #1 10-05-2011, 10:17 PM

My SLS pump is leaking at the seam between the two pump halves. I have seen this thread: SLS Pump Rebuild Kit or Components?, and I replaced the o-ring that is red in the picture TWICE and it is still leaking.

In the seal kit that I got, there is a second thicker o-ring. In the picture it appears that the outer case is aluminum and the inner part that has the channel for the o-ring is steel. I'm thinking that the steel part is sealed to the case by a second inner o-ring. Has anyone removed that center section? Any advice?

libbybapa · #2 10-05-2011, 11:49 PM

Nevermind... I answered my own question. I removed the pump... again... and disassembled it more completely this time.

Sure enough, there's not just one more o-ring, but two more... and neither one is remotely close to the size of the single extra o-ring in the seal kit...

Ah well. I'll see how well I can match it up at the industrial supply place on my next day off.

vstech · #3 10-06-2011, 08:07 AM

we do not appear to have an SLS rebuild DIY pictorial, your pics are very good. when you solve this could you add to this thread, and explain what you found with part numbers or o-ring sizes?
thanks!

libbybapa · #4 10-06-2011, 10:04 AM

Sure, will do.

As an aside, I can't believe these pumps are $1200+ new. That is just completely absurd. The materials/machining required is less than $100 trolley jack. That's one of the most extreme cases of price gouging I've ever seen.

Zacharias · #5 10-06-2011, 01:45 PM

Quote:

Originally Posted by libbybapa

I can't believe these pumps are $1200+ new. That is just completely absurd. The materials/machining required is less than $100 trolley jack. That's one of the most extreme cases of price gouging I've ever seen.

Yes but if the trolley jack says "Made in Germany" on it, you can bet it won't be $100 either....

libbybapa · #6 10-06-2011, 02:21 PM

Even if it says Made In Germany it still won't be anywhere near $1200...

The SLS pump is about 1/100th of the manufacturing of a VE injection pump and 1/200th an inline pump. With those made in Germany, they still don't carry price tags of $100,000-$200,000. If appropriately priced, a new SLS pump would be expensive at $200. I think you could pay a union machinist for a one-off and still be less than $1200.

libbybapa · #7 10-07-2011, 10:58 PM

I got the leak fixed today. I couldn't find anyone with large enough metric o-rings locally and so went with standard ones that were as close as I could find. The ones I used were 3/32" CS x 2-1/8" ID, 1/16" CS x 2-1/2" I/D, and 3/32 CS x 2-1/2 I/D. The one with the smaller I/D went on the outside of the center hub (red in the picture above). The smaller CS of the two with the same ID went around the hub and the larger CS one went in the bottom of the case. With the proper o-rings, the two larger o-rings would be the same with a measurement of 2mm CS x 62mm and the single outer one would be 2mm CS x 54mm. Those measurements are a "best guess" and I obviously hold no responsibility if those measurements do not work for someone in the future. As far as pump dis-assembly is concerned, just pull the shaft out along with the bushing and then tap the case flat onto a piece of wood in order to pop the center hub out. No need to remove the pistons and the center ?stainless? ring. HTH.

LandYaghtLover · #8 10-08-2011, 12:05 PM

Perfect! My pump is leaking BAD. This helps me a lot in thinking I may do the pump sooner than wait for the rear parts I need.

TchTchr · #9 11-24-2011, 11:41 AM

What industrial supply did you use? Who carries this size o-ring? - Grainger, McMaster-Carr?

davidmash · #10 11-24-2011, 01:04 PM

An easier way than hunting around for the rings that may or may not fit is to contact

George Murphy
Performance Analysis Company
perfanalysis@comcast.net
865-482-9175

I got a rebuild kit for the SLS pump on my 190. I think it was about $40-$50 or so. Had the 4 O-rings, paper seal for the back side as well as the cam seal for the back side. Also gave instructions for repair.

I need to order another kit from him to rebuilt a old pump I bought from a member here.

4x4_Welder · #11 11-24-2011, 01:10 PM

Quote:

Originally Posted by Zacharias

Yes but if the trolley jack says "Made in Germany" on it, you can bet it won't be $100 either....

It's not the "made in Germany" that makes it expensive. Really, only $200 is for the pump, $1000 is for that little three pointed star on it.

davidmash · #12 11-24-2011, 01:10 PM

Quote:

Originally Posted by libbybapa

I got the leak fixed today. I couldn't find anyone with large enough metric o-rings locally and so went with standard ones that were as close as I could find. The ones I used were 3/32" CS x 2-1/8" ID, 1/16" CS x 2-1/2" I/D, and 3/32 CS x 2-1/2 I/D. The one with the smaller I/D went on the outside of the center hub (red in the picture above). The smaller CS of the two with the same ID went around the hub and the larger CS one went in the bottom of the case. With the proper o-rings, the two larger o-rings would be the same with a measurement of 2mm CS x 62mm and the single outer one would be 2mm CS x 54mm. Those measurements are a "best guess" and I obviously hold no responsibility if those measurements do not work for someone in the future. As far as pump dis-assembly is concerned, just pull the shaft out along with the bushing and then tap the case flat onto a piece of wood in order to pop the center hub out. No need to remove the pistons and the center ?stainless? ring. HTH.

Actually if you are doing a rebuild you do want to pop the center piece of steel (top right in picture)out that hold the pistons. Assuming yours is the same as my 190, there is a 3rd O-ring on that center piece.

Mine had 3 o-rings, the cam seal on the back side of the rear housing (bottom right in picture. the gold/yellow looking thing in the hole for the cam) and a paper seal to go between the pump and the head on the engine.

Before you pull the pump apart, score the housing from front to back to make it easier to align it when you put it back together.

davidmash · #13 11-24-2011, 01:11 PM

Quote:

Originally Posted by 4x4_Welder

It's not the "made in Germany" that makes it expensive. Really, only $200 is for the pump, $1000 is for that little three pointed star on it.

Also the fact that there are not a lot of cars that use these anymore so it's a 'specialty' item now.

davidmash · #14 11-24-2011, 01:12 PM

Looking at the picture it looks like there may be some minor pupm differences. My pump did not have the wide red seal above but a common black O-ring. Other than that they look the same.

One other thing, when I put mine back together and installed on the car it leaked like a sieve out the back side by the cam seal. I took it off and pushed the cam seal in a bit more (just below the lip of the back housing) and that did the trick. Not a drop as leaked in the past 5 months or so.

libbybapa · #15 11-24-2011, 02:48 PM

In my previous posts I describe in detail the three and only three o-rings that were part of my pump. There was not any need to remove the steel ring or pistons to access any of them.