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Overhaul of a 200 TDI Power Steering Pump

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Whilst I’ve had the engine out of my car I’ve been trying to do all of those little jobs that you never seem to get around to doing.

Time for the steering pump. It’s had a small weep from around the casing, and as I’ve done a couple of Disco pumps in the past I thought I’d treat it to new seals and bearings:


Knock off outer casing



Magnet in the casing


Remove o-ring


Undo front pulley




I like to centre pop everything so I can line stuff back up when re-assembling


Measure position of pulley flange so you refit back at the right depth


Flange is interference fir – you need to pull it off




That never happened before. The flanges on the Disco pumps I’ve done weren’t cast. If I’d have realised, I’d have warmed it up a bit first. Oh well, you live and learn.


Grind a cross in it taking great care not to go through completely and mark the shaft. Support the shaft and one sharp smack with a hammer and chisel and the flange will split











From memory, the pump is a little different to the Disco version inside. I can’t remember the Disco pump having that thin oilite support bearing at the end of the shaft.

In the next photo you can see the main front bearing with the oil scroll.


These are the replacement bearings that I’ve used before to replace the front bearing. I couldn’t get one at the time that was the same length, so fitted two in line. Nor do these have the scroll.

Both other pumps never failed (one did about 100K on them) using these type replacements, so my experience tells me that the scroll isn’t essential.



Anyhow. I couldn’t measure any wear on either of the bearings, so I didn’t replace them. These in the pump casing simply push out, and new ones in quite easily.


I decided to replace the front seal as a matter of course though – although there was no leak.

I had a spare drive flange from a Disco, unfortunately it had been butchered and wasn’t any good. So had to set about to make one out of the piece of steel on the right.













I decided not to make the flange as ‘long’ as the Defender one. This was on the basis that the Disco one never slipped on the shaft, so why would it need all that extra surface area.

Disco flange, new flange and Defender version.





Re-assembly – make new outer o-ring.










Bought the seal on line from here: http://simplybearings.co.uk/shop/index.php?osCsid=9f3e1d8d0d37cad81e49bc8f60403469.

Had the choice of two. Nitrile one for under £2, and a better Viton rubber version for about £7 ish. Forgot to take photo of fitting it.

I went for the ‘expensive’ one!




I use some silicone sealant on the rear housing o-ring.


Remember to line the cover back up with your reference marks and using a bit of wood to spread the load, give it a clout to push it back on. I enter the banjo bolt to ensure all lines up – you can just see it behind the wood.


Now to fitting the front drive flange. I decided to turn up a bit of bar so that I could press it on to the correct depth in one fell swoop.






Heat the flange. It’s a couple of thou interference.


Put counterbored bar on flange and tap it on. You do only have to tap it, not a great whack!




Tightening up the pulley bolts – using an old v belt to hold the pulley.


I marked up the flange in relation to the shaft to see if it does move. If it does, it looks like I’ll have to make another!


There you go, hopefully that’ll save you a couple of hundred quid for a new pump!


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Just a quick question which part of the internals of the pump will make the power steering fluid come out of the top of the reservoir-with the lid on of course, I've got a pump in my garage that I took off my 90 as it was doing this-the one I replaced it with doesn't do this at all, I've never known anything like it for a P.A.S. pump to do that


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Thank you :)

Just a quick question which part of the internals of the pump will make the power steering fluid come out of the top of the reservoir-with the lid on of course, I've got a pump in my garage that I took off my 90 as it was doing this-the one I replaced it with doesn't do this at all, I've never known anything like it for a P.A.S. pump to do that


Sounds like the pressure valve is stuck.

I didn't remove it on this pump as all was well. If you look at the photo where I'm putting silicone on the new large o-ring you'll see a slotted bolt/screw thingy.

You need to be taking this out and exploring in there. I'm a Civil Servant not hydraulics expert so can't give you a theory based 'correct' answer. If I remember correctly, the Disco version has some oil seals in there. As I didn't venture (leaving well alone) in there on this one I can't say. All I can say is it moved freely on this one.

There's nothing special in there that I'm aware of, so don't be worried about taking it apart.

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I do love these home rebuild threads :) Now all I need is a lathe ;)


I couldn't agree more. I couldn't survive without mine. I've had this one for coming up 18 years, and it's been one of the best investments.

It's the fourth one I've had. My fist was a Myford. But for what I want to do I quickly found it on its limit for most of the time. If I had the space, I'd still have one as well though.

For the price of a set of wheels and tyres you can get a decent enough one and you'll wonder what you ever did without it !

Thank you for the pics and thanks for the advice too

It'll be interesting to see if that's it.


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I took the pressure relief valve out like you suggested it was-it wasn't stuck in there but there was some light scoring on the plunger-had a look inside the hole where the plunger sits and couldn't see if it had any damage in there but I did clean the plunger up with a piece of very fine emery cloth will hopefully be it but the one on there at the mo seems to be working ok I will have to wait until the next time til I find out if that's fixed it-hopefully that'll be a long time away yet


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Which Lathe have you currently got? Any advice for a first time buyer?


I've a 1958(?) 6 1/2" Colchester Student round head. It's a gap bed and 24" between centres.

Firstly - I'm not an officiado on lathes! But will try.

More questions first.

1. How much space do you have?

2. What do you think you're going to use it for?

3. Do you have 3 phase?

4. What's your budget?

PM me if you prefer.


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Hi have just done my pump, if you leave the flange on the front of the shaft, strip the pump at the rear and remove the gear with all the holes and pins in, there is a torpedo shaped drive pin (bit like a woodruff key) remove that and the whole shaft complete with flange comes out of the front, this might help any one who hasn't got axcess to pullers and lathes...

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Talk about can't see the wood for the trees!

That is so bl**dy obvious! And would've saved me plenty of time.

I think I was so focussed on removing the flange as I think (memory failure!) that is the only way to do it on a Disco pump. Good call mate.


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  • 2 years later...
  • 1 year later...

Hi Shaun, your explanation and photos are fantastic, thanks for taking the time to post this. Just wanted some advice though, I have this leak problem as well and want to go ahead with the overhaul but want to get the seals/bearings & inserts before I start taking the Disco off the road as living in rural Spain I don't have access to many LR spares and once the the thing is in bits I will have no transport. I want to order the parts on line so can you tell me what is the OD & ID of the bearing required, or better still its reference from "Simply Bearings Ltd" What about the inserts where did they come from? Do you have any specs for them or a reference. Any info would be most helpful.



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