michaelf wrote
"I found so much mud in the bottom of the tank when I cleaned it"

This is a sure indication the previous owner[s] never maintained the system. They either never flushed it or used the wrong fluid. It should be flushed every few years with the correct Febi 2615 fluid.

Unfortunately, you probably have crud in the entire system including the controller and accumulators. Before I'd invest in another pump, I'd change the filter in the reservoir and thoroughly "flush" the entire system with the correct Febi fluid until it runs clear. Then use another new filter. You might be able to reverse flush the system using a Power Bleeder, typically used for brake systems.

Bob thanks for the advice. I will see if the shop has a power bleeder.

Michael

__________________
1990 300E 264,000 miles
1992 300TE 188,000 miles

Or:


HYDROPNEUMATIC SUSPENSION FLUSH

Application: 123 & 124 wagons, S-class sedans, 6.9s, 201 16-valve

DO THIS EVERY 30,000 MILES!

Here's how its done: (Have 2 friends ready - one heavy friend at the rear
of the car and one in the driver's seat standing by to help...(can be any
weight)...

1 - Remove the fluid return line from the top of hydraulic fluid reservoir
and remove fill cap - use a piece of scrap hose to route return line oil to
a 1 gallon container placed under the car to catch old fluid as it comes out.

2 - The filter is located under the fill cap - part no 002-184-55-01 -
remove old one and leave cap off reservoir.

(Some Euro models require removal of the level control valve from the top of
reservoir)

3 - Have 3 liters of new fluid ready to pour into reservoir - take lid off
bottle (part no 000 989 91 03 - $7.50 per liter from me) and remove foil
seal because you have to be fast about this. Use a turkey baster to remove
all old fluid from the reservoir, then add about a liter of new fluid.

4 - Have one friend start the car; have other (heavier) friend bounce rear
of car to exercise rear suspension while you pour new hydraulic fluid into
reservoir as it is pumped through system and into catch bucket under car -
this is called feed and bleed...you have to keep feeding in new fluid as the
old fluid is pumped into catch bucket under the car.

5 - When new clean fluid emerges from return hose, shut off engine (and stop
bouncing rear of car). Fill reservoir to correct level as marked on side of
reservoir. Install new filter and re-connect return line to closure cap
assembly. Start car and check for leaks and top up fluid level if necessary.

Credit to George Murphy, MBCA Tech Editor

Finally the system is working after replacing the power steering pump. No bleeding was done and the system started working as soon as the car started. Amazing!

FYI: Additional info

The refub pump:
I got a pump from Maval manufacturing and it cost me $307.00 including shipping and the core. Returning the core they would credit me $50.00. Maval is working mainly with distributors, but I was able to get one from them. Previously, I posted a link to their web sales where they sell the pump for $207.41, but when I spoke to them they said they didn’t have enough cores to cover demand and they had a good amount of back orders. I didn’t discuss price since eventually they where willing to sell me one, so it cost me a little more but I’m happy I got the car working. They did mention they offer a service that you send them your pump, they rebuilt it and mail it back to you. If anyone is interested will have to call them and see if they would still do it. Their number is 330 405-1600.

A used Vickers pump 124 460 15 80:
When Maval originally told me they didn't know if they had one available for me, I got a used pump locally for $100.00. If it didn't work, I could then use it as a core. The people I bought it form, claimed the pump was in good working condition. The pump seems to be working because with a 1/8 of a turn, fluid squirts out of the output. The reason I didn’t install it was because the owner of the shop didn’t feel comfortable installing a used pump. He said is too much labor involved and didn’t want to do the work twice. Since I get other fringe benefits in this shop, like been able to be on top of them on critical work , or doing work by my self, I went along with ordering a refub pump. By that time Maval was willing to send me a rebuilt pump and charge me for the core.

Discussion with Maval mechanic:
I asked him if there is no an external leeks, or noise from the pump, what could go wrong internally with the pump. He said that the seal between chambers (power steering – hydraulic suspension) could fail. So with a used pump you get a 50-50 chance.
I think my pump had a plugged check valve, not allowing the fluid to enter the chamber, as discussed earlier in this thread.

Pumps available for sale:
My original, not working pump (Vickers pump 124 460 15 80), to be used as a core if Maval is willing to rebuilt it for you. If it helps someone, I’m willing to sell it for what I paid for as a core. $50.00. If there is no interest, I will just return it to Maval. I can wait a week before I return it.
The used pump I bought (Vickers pump 124 460 15 80). Supposedly is working, but I cannot guarantee it since I don’t have the equipment to test it. I will also sell it for what I paid for, $100.00.

Thanks for your help,
Michael

__________________
1990 300E 264,000 miles
1992 300TE 188,000 miles

I am pretty confident my lack of SLS is due to my tandem pump not putting adequate pressure to raise rear.

I am planning to get a used junkyard Vickers 124-460-15-80 Tandem pump and rebuild it using the Febi seal kit since the kit is only $18.

Anybody done this?

I found this youtube video and it doesn't seem incredibly difficult...
Rebuilding the Self-Leveling System Pump in a W126 Mercedes - YouTube

__________________
2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

I have a 92 300te, I replaced the adjustment rod on the SLS Valve. When I put weight in the car it does go up, but it wont come back down after I remove the weight. any ideas?

I'll give this a shot, I remember going through all that, but it's been almost 4 yrs since I sold that wagon... regretting it.
Anyway, maybe it just needs time to bleed down? How long does it stay up? Do you have issues with harshness?
When you say you replaced the adjustment arm... why did it need replacing? IIRC, the valve opens up via the rod when the car sits low... redirecting hydraulic fluid to the rams thereby raising the car... when it reaches the set height the valve closes. And the fluid recirculates. I think it just needs time to bleed out. Cause if the bleed orifice is clogged the car would not stop rising...you'll know this when fluid bursts out the seals.

Manually actuate the valve... disconnect the rod. See if rises and falls. May just be an adjustment issue.

edit: make that 7 yrs...

__________________

85 190E 2.3(SOLD)
86 230E (-->300D) sold
87 300D (-->300TD) sold
68 250S w/ a 615 and manual tranny (RIP)
87 300TD (SOLD)
95 S280 "The KRAKEN" (Turbo 2.9 602 transplant) traded
86 190E 2.3... current project

it does not seem to go down...unless I manually go underneath the car and do what you say by disconnecting the adjustment rod. I am wondering if air in the system could cause this? If maybe the system needs to be bled?

Wait... So when you manually move the rod/valve it goes back down? Then its just a matter of adjusting the rod to the correct length. You're almost there buddy.