At last year's MoT test (annual roadworthiness test) the supply hose to the rack had a modest coating of fluid. At that point I had not noted any loss of level in the reservoir. The quantity of fluid was tiny and the source not obvious so I chose to ignore it unless/until it got worse. The loss of level started to become a once a month top up, and last month became once a week - so time to investigate.

I sprayed degreasing fluid and jet washed the pump, hoses, steering rack, put the car up on stands and left it overnight to identify the source of the leak. The source appeared to be from the WIRING LOOM - weird!

Eventually after several rounds of 'clean everything off and leave overnight' I convinced myself the leak was coming from what appeared to be a pressure switch screwed into a boss where the hard pipe from the pump met the flexible hose. The leaking fluid was making its way out through the electrical connection, into the wiring harness and out of the harness again.

JTIS was conspicuous by its silence on the existence of this mysterious pressure switch. After much head scratching and googling I identified the fact that the mysterious object was indeed a pressure switch and that I could not source just the switch but had to buy the complete hose assembly.

Jaguar S Type Power Steering Hose - Steering Pump Hose - Genuine - 2000 2001 2002 2005 00 01 02 05 - PartsGeek.com

Mine is a RHD 3 litre Petrol Manual prefacelift version. Turned out early cars had a 2 piece item - the hard pipe from pump/boss/pressure switch was one item, the flexible hose and hard pipe to rack a separate item. Later cars have a one piece item. The change over year was around 2001. Unless you have seen both before I know of no way to tell the two types apart.

Guess which year mine is.

2001.

Fortunately the original (Ford) part number label was still on the hose and a UK online supplier could identify it as the one piece item and supply the part.

The LHD (Jaguar) part number is XR8-33363 . Not sure of the UK (Jaguar) part number until the item arrives.

Now to the reason for this post. Confident that this part is en route I removed the hose and once on the bench unscrewed the pressure switch (14mm spanner). A hairline crack reached half way around the brown plastic top of the switch, so the source of the leak is confirmed.

It carries the Ford part number XW43-3N824-AA0312.

Googling that shows I'm not the first to suffer a leak from there:

'Lower' Power Steering Pressure Switch - part 3N824 confusion - Lincoln vs Cadillac

I can find a source for a container load of probably fake parts:

Ford?steering pressure switch?XW43-3N824-AA?XW433N824AA?XW43-3N8-Guangzhou Xiuyan Auto Parts Co.,Ltd

but not for one genuine one.

Too late for me, but you chaps over in Canada or the United States may have more luck sourcing this Ford US part for pennies rather than the whole Jaguar subassembly for pounds than I did.

And if you think you see power steering fluid emerging from the wiring loom - you aren't hallucinating

 

Thanks - the problem you describe is exactly what I have and my car is also a 2001 (on the cusp of the changeover). My car is pre-facelift, so I assume that it's the earlier part.

The part numbers will hopefully save me a fortune.

By the way - small world, isn't it? I usually "run into" members of the Cosic family on Rover fora

 

I had the same leak on my wife's 2003 Lincoln LS. Changed the P/S pump first but that was not it. Put the old pump back on. The leak was coming right out of the wires. The pressure sensor had failed internally.

Looks like there are two switches depending on your setup. One switch on the P/S pump.
Like this:





Here is the one I had leaking. It's in the steel section of the pressure hose. Does not look like Jaguar has this separate from the hose assembly. But you can use Ford #XW4Z-3N824-AA about $40-$50.




Here is what the switch looks like.


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That's the beastie - number 5. My local Ford/Jag/Lincoln dealer out here in Abu Dhabi said that it wasn't easy to get hold of parts for such an old car (2001 S-type!) but he can get it from the US for the equivalent of $62 including shipping but that it would take 2-3 weeks.

Can anyone suggest somewhere to get one more quickly? My usual option of RockAuto Parts Catalog doesn't do them and partsgeek only seem to sell them as part of the pipe ($160 + shipping)

 

I went for the Lincoln dealer in the end - in the meantime I plan to put an old Jeep oil pressure sender in there to block the leak whilst I wait for the new one to arrive.

 

The dealer came through with the part after just 3 days and gave me an unexpected discount (charging just $45 / £29). Fitting was a bit awkward but I found that supporting the car on axle stands (jack stands) and unbolting the steering rack from the crossmember gave me enough access.

Oddly the old one needed a 14mm spanner and the new one needed 15mm

Leak gone - owner happy Next job - front dampers (new genuine Jaguar ones awaiting fitment)

 

Hey glad the dealer treated you a bit nice on that part!!

That's a lot better than buying the entire hose assembly with the pressure switch!
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Sorry Richard, only just seen this response!

I'm so used to your Forum which emails me every time a response is posted that I missed you!

We now have:

1993 K Reg XJ40 - Dusan bashed it into the garage wall whilst fixing TB and LPG system!
R reg X308 - Marko is converting into a Phaeton
52 Reg X308 Daimler SuperV8 (AKA Rolling Thunder) - Alexander's little local runabout
as yet unknown X308 - apparently arriving over Xmas, engine destined for the Phaeton and 18" Daimler wheels for Rolling Thunder - rest for the old man to dispose of I've just been informed.

Dusan is still rolling around in the gassed 800.
Alexander is thinking of selling his Skoda 2.0 TDi and it's here on loan to Antipodean visitors in the meantime.
One each MkI and Mk II MX-5s and an Honda Insight complete the stable.
The Land Rover 'Twink' is now minus engine transmission and parked up here.
My 420 is still gathering dust in the garage.

We sometimes have room to park our Jag on the drive!

Offspring - don't you love 'em

 

I thought I was overdoing it with 2 Jeeps, a Jaguar and my wife's Kia Soul - and only 2 allocated parking spaces! One Jeep has to go and if I ever find a nice, affordable XJ40, X300 or X308 then the S-type will be leaving.

 

I'll post one of ours out to you then??

 

At £7 per kilo that might be a bit expensive!

 

That looks like a AU Falcon Power steering switch for $15.00