Power steering pump.

[Druk]

I have my 300d engine now running in the car but there is no power steering. The pump is the correct one for the engine but not for the 107 steering box although it's the same pump visually as that fitted to a 107 as standard. The pump was fitted with a recon kit by me, and the box has been overhauled by a supposedly reputable outfit in Devon. Power Steering Rack | Power Steering Boxes - Kelly Bray Steering
I've tried the recommended bleeding procedure and ...nothing!

Before I strip the pump for another looksee are there any suggestions please? Does anyone know the working pressures of this and the later plastic tank pump from a W210? I believe the 210 pump had a higher pressure cos of the rack steering but it would be good if I could safely substitute this for the 124 pump.

This pump...






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[Dieselman]

I would think pressure of 130Bar would be about right.

Is there a decent flow from the return pipe, if so it is likely to be the steering box rotary valve at fault.

 

[grober]

This of any help? Model 107

and

http://www.startekinfo.com/StarTek/outside/12264/disc_2/Program/steering.htm

 

[Druk]

Thanks both.

I've now determined that the pump I have fitted is 110bar. The 107 workshop manual says about the pump that was originally fitted has a test pressure of 65bar. but. working pressure of 5bar. (5bar seems reasonable?)

I find it hard to believe that any vane pump would output 110bar...1600psi???

What does 'test pressure' refer to against working pressure?

How would I find the working pressure of a W210 pump, the one with the plastic tank? Which I also have.

Searching the link Graeme posted shows a W201 has a pressure of 65bar or 85 bar depending on model, the 85bar version being quoted as giving easier steering. I'm wondering if I used an 85bar pump through the 107 steering box if it would give 'easier' steering or would something blow?

 

[Druk]

Will.

I've asked of the folk who (supposedly) reconned the box if I could possibly have blown something internally and their reply was along the lines of...'not if it's not leaking from an external seal'. I got the impression that if something's gone inside, the shaft lip seals can't cope with the leaking internal pressure. Unless you know different.

However, I must say, I don't have a lot of confidence in their work.

I'm still assembling couplings to test the flow/return without having oil spewing all over the place.


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[LTD]

Maybe you could ask the question on the official MB forum ? I'm sure they'd just love to help you out !!!!

On a serious note, your dedication to overcoming all these problems is something I'll never fail to admire.

 

[Druk]

Maybe you could ask the question on the official MB forum ? I'm sure they'd just love to help you out !!!

Indeed.

And thanks... Had it out the garage under it's own steam yesterday. Not long now.

Edit...scrub the 210 plastic tank idea. I've just been advised (on the owners forum ) that it uses different fluid so probably wouldn't be a good idea to run it with a 107 box.


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[grober]

Think the test pressure refers to the idling pressure when the pump is not doing any work. [ bit like a resting pulse rate] the working pressure will be higher but depend on the load put on the pump and engine rpm so will vary. Hence the change in engine note when the steering goes up against the stops?? I guess its possible you might have blown something internally but you may not have ever reached "critical pressure" if the pump was merely idling.

This might give you some ideas refers to a W126 box but as the article says most MB boxes work on the same principle. How to reseal a MB steering gear

 

[Druk]

Well the good news is it appears to be the pump that is the problem. Filled it with fluid, ran a pipe to a container and started the engine.

Zip. Nil. Nothing. not a drop. Whatever I've done when I put a new seal kit in it I've assembled it wrongly. fail.

Maybe a blessing in disguise too. I'm now on the hunt for an early W201 190e 65bar pump which will fit to the new engine and replicate the original pressure. A201 460 11 80 or A201 460 12 80

Thanks for all your help. Appreciated.

 

[hismajestics]

Well the good news is it appears to be the pump that is the problem. Filled it with fluid, ran a pipe to a container and started the engine.

Zip. Nil. Nothing. not a drop. Whatever I've done when I put a new seal kit in it I've assembled it wrongly. fail.

Maybe a blessing in disguise too. I'm now on the hunt for an early W201 190e 65bar pump which will fit to the new engine and replicate the original pressure. A201 460 11 80 or A201 460 12 80

Thanks for all your help. Appreciated.

Picking up the subject again...

Would this 65 bar pump be sufficient for my 82 bar steering box (W114 Coupe)? Will it fit a M104 engine?

As of now I have on the M104 the original tandem pump of 110 bar fitted. With this high pressure the steering box seals might be at risk? Any professional view on this?

/johannes

 

[optimusprime]

inf

I may be wrong but I thought the low pressure hose went to the top of the pump. Not sure .

 

[jaymanek]

He must have sorted it as he has been driving it to various shows since then!

 

[Druk]

Picking up the subject again...

Would this 65 bar pump be sufficient for my 82 bar steering box (W114 Coupe)? Will it fit a M104 engine?

As of now I have on the M104 the original tandem pump of 110 bar fitted. With this high pressure the steering box seals might be at risk? Any professional view on this?

/johannes

The 65 bar pump will fit the M104 engine, it came from an M102 which has the same mountings. You may have to change the multi-v belt pulley as some of them are different diameters and maybe the brackets. It's the early cast iron integral pump on the M110 engine that wont fit the M102/03/and 04 series engines. I think the 65 bar pump will probably be OK on an 82 bar box. Maybe the assistance will be slightly less but that's all. However I was unsure if a greater pressure pump would destroy the seals in a lower pressure box which is why I changed mine.
As Jay pointed out I've been running mine for a year now and all seems OK with the steering.


The return does go to the top port of the pump.