HOW-TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

[bgalakazam]

Re: Power Steering Pump Leak Investigation

Well after the reseal of the reservoir and pump and the cam solenoids and putting it back together... I am not noticing any improvement in the power steering, it's the same state.

On top of that 2 sounds came up:
- when you turn the wheel as if the system is low on PS fluid. It's not, I checked and added on running engine
- a weird buzzing sound from the left bank (driver's side). Can't tell if it's from the cam solenoid, the cap and rotor or the pump. Sounds like it's from the top. I did tighten everything accordingly so don't know.

kind of disappointed that PS didn't improve. At leaste I resealed the cam solenoids. Now I have to investigate the sounds. I'll post a video for clarity. Meanwhile, anyway to bleed the system out from air? I remember when I got the car the "smooth" 1 finger PS was available now and then and gradually disappeared.

 

[gerryvz]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Did you move the steering slowly back and forth, lock to lock, a few times, after you were done with the reseal?

Honestly, when I did my tandem pump, I didn't see ANY difference in steering (except it has not leaked a drop since I did the job). My steering (as on all my recirculating-ball Benzes) sounds a bit different when you have the steering at either lock, and reef on the wheel (for example doing a tight-as-possible U-turn), it makes a different noise and has a very slight vibration. It did take a couple of days to work the air out of the system after I did my pump, though.

Cheers,
Gerry

 

[bgalakazam]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

The noises are gone after many wheel end to end turns. I did, then I lifted the car on jacks and did it few more times. When wheels are off the ground, the wheel moves like a feather. Then I took a short drive. Now and then it squeeks. There are very tiny bubbles when I check the reservoir, but it's not losing fluid. I think the wheel is actually a bit stiffer. I'll keep driving and monitoring, hopefully the air gets out.... I am just used to the new cars with the weightless steering wheels. Is the W124 supposed to feel this way? I mean I can turn, but it's nowhere near weightless steering.

 

[emerydc8]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

When you reinserted the 10 rectangular pump paddles in the daisy wheel, did you make sure that the round sides were facing the cam insert? If you missed even one or two, it could cause you to have less power assist.

 

[bgalakazam]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

When you reinserted the 10 rectangular pump paddles in the daisy wheel, did you make sure that the round sides were facing the cam insert? If you missed even one or two, it could cause you to have less power assist.

I couldn't get that part out, so I didn't open it that far. I replaced the outer weird shape black and clear seals, and the round one. My leak was coming from the hose for sure and it's dry now. But I was also expecting a smooth steering. Do you have it smooth and weightless on your E420s? I just don't know how much resistance there should be on the W124 PS, I am comparing it to much newer cars.

 

[gsxr]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

The 124 power assist is not excessive where you can spin the steering wheel with your pinky finger. MB left a little bit of steering feel. You should be able to turn it with one hand though. It's hard to describe, you'd need to find another 124 to drive & compare.

 

[bgalakazam]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

OK maybe I was just setting my expectations too high. I have a tendency to trip out too much.

 

[vatc5637]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

In my experience, the W124 steering is always been "heavy" (required more steering effort) as compared to the other MB's I've owned (W210, W230). Smooth? yes, weightless? not even close. In fact, my .034 steering feels "lighter" than my .036 version. So if you were expecting 1 finger steering when parallel parking, I don't think the W124 was ever that "light". For me personally, the test was one hand parallel parking (all that I expected) versus two handed push-pull steering for a non-assisted unit. My bias has always been to a "less assisted" feel.

 

[baviking1]

Re: Power Steering Pump Leak Investigation

For the tandem pump, several of the seals and o-rings are only available in the kit, not separately. This forces you to buy the entire tandem pump repair kit to get all needed items. The part numbers for the tandem pump kits, and approximate price, is:

ZF tandem pump: 000 460 37 80 -- List $34.50; parts.com $24.60
Vickers/LuK tandem pump: 000 460 45 80 -- List $112; parts.com $80.40

Hey Gerry; getting ready to tackle this next. Parts.com is giving me a "this make is not available" message on part# 000 460 37 80. Could they have discontinued it since your thread here? Thx....

 

[gsxr]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

I'm seeing it...?

https://www.mboemparts.com/oem-parts/mercedes-benz-seal-kit-0004603780

Current price $37.50 list, $28.13 discounted...

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

I'm seeing it...?

https://www.mboemparts.com/oem-parts/mercedes-benz-seal-kit-0004603780

Current price $37.50 list, $28.13 discounted...

Dont know what the heck happened on my end here (maybe the MB Gods telling me "dont do it"!!). Thx Dave....

 

[gsxr]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Don't forget to double-check if you have ZF or LuK pump before ordering... totally different design, different seal kits, etc.

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Don't forget to double-check if you have ZF or LuK pump before ordering... totally different design, different seal kits, etc.

I'm pretty sure its the ZUF (see green tag), but crawling under there in the A.M. to make sure. Should I be concerned parts.com has it listed for an sl600 and NOT an e500?

Sure wish I didnt have to do THIS job, but I figure I might as well do it while I am replacing the cam oilers w the '92 aluminum tubes. SOMETHING'S wrong there; still that ungodly "bad-power-steering-pump" whine (which is almost impossible to trace), and SLS fluid is leaking pretty well. What's baffling is that it seems to be coming from underneath the steering pump/driver's side, yet the fluid isnt red (its yellow hydraulic for sure).

 

[gerryvz]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Should I be concerned parts.com has it listed for an sl600 and NOT an e500?

You need to keep an MB specific parts lookup link for parts.com bookmarked on your browser. Use the EPC first to obtain the proper part numbers (or this site if provided) and then use your parts.com link to pull up the prices for the part.

DO NOT use the parts.com catalog. You only should EVER use the parts lookup page, and have the part numbers that you want already in hand. Then plug them in one by one and add them to your shopping cart, and then go to the next part number, and then complete your order.

 

[gsxr]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

P/S leaks (on a tandem pump) are almost always the hose between the reservoir and the pump, or the S-shaped hose to the frame rail, or possibly the reservoir. It's almost never the pump itself.

SLS leaks are usually either the short sections of cloth-covered hose (assuming they are original), or the pump front seal.

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

You need to keep an MB specific parts lookup link for parts.com bookmarked on your browser. Use the EPC first to obtain the proper part numbers (or this site if provided) and then use your parts.com link to pull up the prices for the part.

DO NOT use the parts.com catalog. You only should EVER use the parts lookup page, and have the part numbers that you want already in hand. Then plug them in one by one and add them to your shopping cart, and then go to the next part number, and then complete your order.

Yup, I always do that (use the free EPC at Mercedes of South Atlanta site). I must have missed a number in the cut & paste in my haste (eeew, a bad rhymn)......

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

P/S leaks (on a tandem pump) are almost always the hose between the reservoir and the pump, or the S-shaped hose to the frame rail, or possibly the reservoir. It's almost never the pump itself.

SLS leaks are usually either the short sections of cloth-covered hose (assuming they are original), or the pump front seal.

I'm almost CERTAIN you are right (i.e. the cloth-covered hose is leaking), but its that whine that is making me think I need to rebuild the pump. That and the fact I'm coming up on 200k miles (I mean it will need it eventually, right?).......

 

[gerryvz]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

At that mileage I'd rebuild the pump & replace the hoses.

 

[emerydc8]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Baviking1,

What kind of fluid are you using in the pump? I haven't heard of any actual hard parts like bushings failing on these--It's mostly the rubber seals. I once put the wrong fluid in a domestic car and it screeched like you are describing. Just curious.

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Baviking1,

What kind of fluid are you using in the pump? I haven't heard of any actual hard parts like bushings failing on these--It's mostly the rubber seals. I once put the wrong fluid in a domestic car and it screeched like you are describing. Just curious.

Hi Emery, the car had the whine when I got it several weeks back. I am ASSUMING it had the proper hydraulic fluid, but didnt take any chances and immediately changed ALL the fluids in the car. The hydraulic was so filthy it resembled tar :-(. I used a sucking machine to bleed the lines completely until new fluid came through, as well as get all the residue from the bottom of the SLS reservoir. Now sporting OE hydraulic fluid (and whine is still there)......

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

At that mileage I'd rebus the pump & replace the hoses


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Absolutely. I guess the time is now, since I'll be pulling the valve covers to install the aluminum oiler tubes anyway. The whine almost sounds like a bearing though; wondering if it could be in the air pump? It almost sounds like a super/turbocharger belt whine (wouldst that it were so!!).....

 

[gerryvz]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

The air pump only engages for a minute or two when the car is first started up from cold. A clutch should disengage it otherwise. So you shouldn't often hear the air pump except at startup.

I did a HOW-TO on the aluminum oiler tubes so be sure to reference that when you do that job. And take care when re-installing the valve covers so that everything gets re-sealed correctly

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

The air pump only engages for a minute or two when the car is first started up from cold. A clutch should disengage it otherwise. So you shouldn't often hear the air pump except at startup.

I did a HOW-TO on the aluminum oiler tubes so be sure to reference that when you do that job. And take care when re-installing the valve covers so that everything gets re-sealed correctly

I have that thread printed out and ready to roll, just like the tandem pump thread. I'm guessing then my turbo whine can ONLY be the tandem now that the air pump has been eliminated...

 

[emerydc8]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

I'm guessing then my turbo whine can ONLY be the tandem now that the air pump has been eliminated...

Have you used a stethoscope or long screw driver to try and pinpoint the noise? How about the water pump?

 

[gsxr]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Have you used a stethoscope or long screw driver to try and pinpoint the noise? How about the water pump?

...or tensioner pulley, alternator, AC compressor... I'd try running the engine (briefly!) with belt removed, to confirm the noise goes away. That will prove it's one of the belt-driven devices.

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Have you used a stethoscope or long screw driver to try and pinpoint the noise? How about the water pump?

I tried a long screwdriver, but results were inconclusive (at least to me). I have a minor case of tinitus (too much stage volume over the years), so its tough to pinpoint it that way.

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

...or tensioner pulley, alternator, AC compressor... I'd try running the engine (briefly!) with belt removed, to confirm the noise goes away. That will prove it's one of the belt-driven devices.

I will try that too, good idea (although it would frighten me to imagine what the cause was if it DIDNT go away). Given as I've already ordered the seal kit, I'll go ahead and rebuild the pump anyway. What the heck; its only time and minor $$, right?

 

[8899]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

The whine almost sounds like a bearing though; wondering if it could be in the air pump? It almost sounds like a super/turbocharger belt whine (wouldst that it were so!!).....

A bearing in the water pump perhaps?

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

A bearing in the water pump perhaps?

I've never heard a water pump sound like this, but I guess its possible...??

 

[baviking1]

Re: Power Steering Pump Leak Investigation

A couple questions here Gerry:

A)Were you actually able to SEE the top bolt at any time? I cant, and am thinking I might not have the car jacked up enough.

B)If the answer is "no", how did you get the hex socket into the bolt, blind luck?

Maybe we should start a thread about how poorly-engineered the SLS pump mounting is (although that wont get my last bolt out).....

 

[gsxr]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Photos of that top bolt (on the back side) are here:
http://www.w124performance.com/images/M119/PS_pumps/

As noted in the pics, it's easier to see if you remove the side splash shield (with the rubbers that go around the sway bar).

 

[baviking1]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Photos of that top bolt (on the back side) are here:
http://www.w124performance.com/images/M119/PS_pumps/

As noted in the pics, it's easier to see if you remove the side splash shield (with the rubbers that go around the sway bar).

Thx Dave, I'll pop off the shield. That is one tight spot....

 

[baviking1]

Re: Power Steering Pump Leak Investigation

SLS pump rebuilt and installed with the help of this great how-to. I would add just ONE suggestion: I think it might be prudent to put the difficult rear bolts in BEFORE the nipple is pushed down into the new short rubber hose (and the hose clamps are tightened). In my case, not doing so made it almost impossible to correctly align the back bolts, and I ended up having to chase the threads on the lower pump hole from the resultant cross threading (even though the front bolts were as loose as could be). No worries, its ready to roll now..... Thx!!

 

[baviking1]

Re: Power Steering Pump Leak Investigation

Any other use for the rest of the tube of the anaerobic sealant (besides my other W124 cam solenoids)? Hate wasting anything...

 

[gsxr]

Re: Power Steering Pump Leak Investigation

Any other use for the rest of the tube of the anaerobic sealant (besides my other W124 cam solenoids)? Hate wasting anything...

It's used on the front head covers (the aluminum thingy the cam solenoid bolts to). You need to pull the head covers when replacing the chain rails. It's also used to coat certain bolt threads, like the top long bolt on the power steering pump bracket, and two of the bolts for the smog pump bracket, as these go into areas which are exposed to oil. And, it's used for the timing cover to block, just pray you never need to do that job.

The good news is, the koala-claw orange goo lasts a very long time, despite the package claims otherwise. I just used some purchased 10-12 years ago, let it cure about a week before starting the engine, and so far it's been leak-free. Store it in a relatively cool area and it should be fine. Good stuff to have around.

 

[baviking1]

Re: Power Steering Pump Leak Investigation

It's used on the front head covers (the aluminum thingy the cam solenoid bolts to). You need to pull the head covers when replacing the chain rails. It's also used to coat certain bolt threads, like the top long bolt on the power steering pump bracket, and two of the bolts for the smog pump bracket, as these go into areas which are exposed to oil. And, it's used for the timing cover to block, just pray you never need to do that job.

The good news is, the koala-claw orange goo lasts a very long time, despite the package claims otherwise. I just used some purchased 10-12 years ago, let it cure about a week before starting the engine, and so far it's been leak-free. Store it in a relatively cool area and it should be fine. Good stuff to have around.

Thx Dave, good to know it will have a future use.

Re: the timing cover, I'm about 4 hours into reinstalling my air pump (pretty much the last major thing left of my initial 60 day odyssey with the 500). I cant imagine a job less pleasant (with less room to maneuver) than this one!! Maybe we should start a separate thread "Most miserable task ever undertaken on your 036".....

 

[gsxr]

Re: Power Steering Pump Leak Investigation

Re: the timing cover, I'm about 4 hours into reinstalling my air pump (pretty much the last major thing left of my initial 60 day odyssey with the 500). I cant imagine a job less pleasant (with less room to maneuver) than this one!! Maybe we should start a separate thread "Most miserable task ever undertaken on your 036".....

The smog pump swap really isn't too bad, unless a hose breaks and you're stuck waiting a week for parts, etc. Remember that for the bracket, two of the bolts require the orange anaerobic koala-claw goo on the threads... if you're not sure which two (of 3 total) need it, just apply to all three:

 

[8899]

Re: Power Steering Pump Leak Investigation

Next up is disconnection of the hoses from the driver's side of the pump. There are three connections: a rubber hose, a large 17mm metal fitting, and a 17mm banjo bolt

Anyone happen to know the part number for that particular rubber hose? I am referring to post #39.

 

[gsxr]

Re: Power Steering Pump Leak Investigation

Anyone happen to know the part number for that particular rubber hose? I am referring to post #39.

The short rubber hose, which is for the SLS inlet? That is p/n 114-997-04-82 and sold by the meter. There is another section below the SLS reservoir. You need less than half a meter to change both. IIRC, the OE hose has a braided cover, the aftermarket hose does not.

 

[8899]

Re: HOW TO: Removing and re-sealing ZF tandem pump (SLS and power steering)

Thanks Dave. So yea, I'm referring to this hose:

 

[DerFuror]

Re: Power Steering Pump Leak Investigation

...Next up is to remove the plastic piece that surrounds the distributor cap and cam advance solenoid. It's held on by three bolts, 5mm Allen. I used a long allen key to get at them. The one on the bottom is sort of hidden, so you have to use your long Allen key to "feel" for the socket that the end of the key fits into. Once you have it in position, I used a box-end wrench on the upturned (short) end of the allen key as a lever to loosen it ... it was too tight to loosen by hand only. It worked quite well...

That bottom bolt is very tucked away!

Just a little addendum to this excellent HOW-TO regarding a tool which will make this task simple to complete. 5mm extended reach Allen socket does the trick quick. This particular one is Carlyle brand from NAPA with a 6" reach for 3/8" ratchet.



I use this 5mm tool quite a bit on the 500E. It provides the reach & torquing leverage to help prevent socket rounding-off.

I panicked when I initially couldn't find it...but I did find it right where I last left it...and it was where it should have been. I should have looked there first!

 

[gerryvz]

I used an extension & "regular" socket to do this, but I can see how an extended socket would be a better solution. Need to get a set of those pups. Thx for sharing.

So, was your job successful? Did you replace the cam adjusters? Using the orange koala-claw/satsuma MB goo?

 

[DerFuror]

So, was your job successful? Did you replace the cam adjusters? Using the orange koala-claw/satsuma MB goo?

So far so good, but now I have to wait for some parts.

I lucked out with the cam adjuster. Dry. Hopefully the other side will be dry, too.

I was pricing Loctite 574 this morning @ $26.

 

[DerFuror]

Power Steering Reservoir Mounting Stud

FYI. The Power Steering Reservoir Mounting Stud (p/n 129 466 02 70), originally an E10 Torx design, may have been superceded by a 5mm Allen socket head design.



I quickly placed an order last week because Darvin said there was only one stud left in NJ. So this design either supercedes the torx or it was a substitute because that lone torx stud was depleted before being picked for my order.

My net result is still 3 torx to one Allen socket, but the reservoir is mounted & I'm moving on to the next job.

 

[gerryvz]

These are one of the rare "reverse Torx" bolts that I have seen standard on the E500E, actually. I had to buy a new set of sockets just to deal with them when I did this reservoir job.

These "female" or "reverse" Torx bolts are now exceedingly common on MBs, and what I have seen is that quite a few of the original E500E bolts have been "superseded" from hex-head bolts TO these reverse Torx bolts.

 

[JC220]

Great writeup – but unfortunately my car has the Luk Pump ££ Seal Kit and I can’t find a DIY out there – does anyone know of a DIY on the Luk Pump?




Mine is covered in crud – but not actively leaking yet. I intend to re-seal it soon when the car is in storage for the winter.


I must admit I’m considering aftermarket on the LUK Seal Kit. Not something I like doing but the MB price is outrageous at £70.48 from a discounter + shipping. (£85) The Luk re-seal kit looks less complex than the ZF one - so why is it so much more expensive??. (Pic attached of a Febi Kit matching the OE ref- £13 delivered)

 

[RicardoD]

Struggling with EPC for a few part numbers for the short hose replacement at the base of the power steering pump

Anyone have part numbers or source for:

- the short hose at the base of the pump​

- hose clamps or Norma clamps, what size?
- aluminum crush washer for reservoir nipple tube​

- gasket part number is 1294660180
​

 

[gsxr]

Ricardo, do you mean the short hose below the base of the reservoir, directly above the pump? Photo attached.

The hose OD should be ~23mm (I think), the EPC says the hose clamp is p/n: 005-997-45-90

Aluminium seal ring for the threaded nipple is: 007603-020100

 

[RicardoD]

Thank you Dave! Therefore to service the short power steering reservoir hose only:

- 15mm ID hose 006-997-09-82 (however this comes up as $56 at mboempart.com!, I am ordering a meter of same part number Cohline hose for $15 at pelican parts.com
http://www.pelicanparts.com/More_Info/006-997-09-82-M20&SuperCat=Y&SVSVSI=3866.htm

- aluminum crush washer 005-997-45-90

- gasket at base or reservoir tank 1294660180 (can use generic $4 vs $27)

- new clamps (optional) Qty 2 of 005-997-45-90

- reservoir return O-ring: 1199970045

Special tools:
12mm hex key socket
female torx socket E8

 

[gerryvz]

Note -- a month or two after you install the short hose, make sure that you re-tighten it as the clamps compress the hose a bit. After a while the compression can cause it to leak/weep a bit, so snugging it down after a period is a good prudent thing to do.


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