Hey guys, just bought a 1996 XJ12 in British Racing Green so very newbie question here. Its in really great shape but PO said it needed a new power steering pump. No leaks and belts seem tight and fluid level ok, but no power steering. These appear to cost around 500 dollars online. Has anyone rebuilt one of these before? If so where do you get the rebuilding kit that is correct for this power steering pump? Any other pumps out there work? Maybe more to check before going this route? Moving on up from my 99 XJ8, hoping this one is nicer to me than the XJ8. I won't have to rebuild the transmission or replace timing components is my hope.

 

Welcome, John Baker and congratulations! Beautiful car in BRG.

No leaks in the power steering system? You're doing all right.

The power steering pump in this car is pretty special, not interchangeable with the six. I've not gone into the pump before, but I see that Rock Auto has inexpensive seal kits for this pump. There are rebuild services that can do yours if it is indeed broken.

One thing to do before you take anything apart is to check that you have a steering control module installed. It is behind the left side kick panel under the dash (side vertical panel). I don't know if it is possible to test it. They have six pins. They seem to be available, but are too costly if you're not sure of the problem.




Another idea would be to purge the system. You can do this by raising the front wheels off the ground, and slowly turning the steering wheel lock to lock a few times. Then repeat with the engine running. That will clear the system of trapped air. It would normally be done after a repair. Its a relatively simple thing to check before digging in.

With the XJ12 you can rest assured that you will most likely never have to open up the engine or transmission. Don't worry, there will be enough other little things to keep you occupied!

 

When you say you have no power steering, how bad is it? Because in my experience, without it it is impossible to drive the car. If you are able to steer the car at all(!) then it’s worth remembering that these cars have electrical speed sensitive racks, is it possible the problem is here?

 

I have had 3, 1996 XJ12 and 1 1995 XJR power steering pumps rebuilt by;
The Rebuilding Factory
orders@rebuildingfactory.com
805-981-3777
I have yet to touch any of my V12's or the transmissions. Although I do have one tranny that will require attention before going back on the road full time. As stated above there are PLENTY of little things to keep you occupied. But "once sorted" they are a dream to own. Only around 180ish '96 XJ12's in North America, not sure about the '95's but chances are you will never see another one on the road.
I like your ride.

 

Wow fantastic responses by everyone this forum is going to be a great resource thanks so much! I've got so many more things to check than I thought. I'll be reporting back soon on what I find.

 

You're welcome John. It could very well be true that you need the pump rebuilt! I think we take Previous Owners' advice with a grain of salt (or simply not to be trusted) and so tend to point to other possibilities too. Is there any real evidence to what the PO might have done as far as diagnosis of the steering?

I bet you got a good deal on this car! Any Jag (especially a V12) with a running problem just kills the resale value. I think you will come out the winner here.

 

im pretty happy with what I paid. It appears to be the front end has been rebuilt? At 100K miles I don’t see any worn rubber bushings. And shocks look new. So happy I don’t have to do this. Interior was almost perfect except for sagging headliner (fixed already) and two broken air vents.

I removed the power steering pump and dissembled it. It was defiantly leaking out the shaft sorry for the incorrect statement earlier (going by PO). I don’t see any wear or anything broken so I’m going to replace all the seals and a see if it still makes that horrible wine. I’m hoping the only issue was with the fluid leaking out around the shaft seal.

 

Can anyone identify this cable that isn’t plugged in? Looks like it comes off the fuel injection harness at the back of the engine. I can’t find what it’s suppose to plug into?

 

I've never seen that connector on my car. Even now, when looking for it. My car is an earlier build, so the harness might be a little different. BUT...

I found it in the engine management wiring diagram! Rest of World vehicles (not Federal or USA/NA spec) have "catalyst thermocouples" and a catalyst switching module. That connector is the unused lead for the thermocouples. Called PI 156, its description, location and wire colors match your photo.

Apparently you will find an usused 8-pin white connector near the ECU or A-pillar, that would attach to the module.

The module ("where fitted") sends the exhaust temperature warning, found only on Japanese market vehicles. I don't know what else it might do.

Thanks for inspiring me to learn about this little detail... I never looked into the exhaust temperature function. That was 20 minutes of good entertainment and a successful investigation! WTH, I've got time.

Glad to hear of the probable solving of the steering problem. No leaks for sure when you're done. Don't forget the purge procedure.

Good to see you are changing out those fuel pressure lines. You might have seen my thread on the subject. Be sure to use the high pressure barrier hose. No clamps necessary. Unless it really makes you feel better.

 

SleekJag your a wealth of information thanks for the research and response! Good to know its not needed. I was afraid the PO had removed something. And yes I found your post about the crossover hose and went to NAPA and got the 225 PSI 3/8 line with the correct SAE rating you posted. Mine looked like they were about to give out soon and leak. It fit very tight so I can't imagine the need for clamps. Not sure what those little rings do but I stuck them back on before pushing the tubing on.

Yes I will not forget the purge procedure for the power steering before starting the engine.

I've been real busy replacing all the coolant hoses and thermostats/gaskets with original jag parts. On my XJ8 there were times aftermarket parts caused more problems than they solved so I'm assuming the same with this car. Gonna flush the coolant out with distilled water as soon as i get it ready to run again.

I've replaced the spark plugs with what came out (NGK BR6EF). I left them at the pregap which was .7mm/.028 on all of them. I noticed the ones that came out had a wider gap of .035 or so. Did I misread the manual or maybe have the wrong manual?

I'm contemplating rebuilding the fuel injectors with a cheap kit I bought off ebay. Bad idea? Found a youtube video and it didn't look too hard. I dont have a way to check the spray pattern after rebuild so thinking might be better to send them off.

Fluids i'm using are G-05 coolant and Mobile 1 5W50 Synthetic. Didn't see too many posts about what to use but from what I could find in the manual and other forums this seems like good choices?

Sorry for all the questions, this is gonna be my daily driver to replace the XJ8 and want to do it right.

 

Well did a pressure check today of the power steering. Had a leak coming from the top of the rack. Dropped it down and see it’s coming from the input shaft. Any way to replace this seal or am I getting a rebuilt MNA3891CB rack now?

 

Me too. Seems like the most common leak point for this rack and the XJ6 rack. I don't know of a seal replacement procedure, but I'd like to. The XJ12 rack is a pretty rare beast - not the same as the six rack.

I take it your steering pump has been revived successfully. Good work.

 

yes pump seems to be holding pressure now. I think all that was wrong was that front shaft seal. Similarly as what I believe is the only thing wrong with the rack. I’ve dissembled the rack and removed the seal which was a real pain. I didn’t realize it was down in a recess in the housing. Now I am attempting to track down a replacement seal.

 

Well still struggling with getting the power steering sorted on my car. So after replacing the seals in the pump, cutting off about an inch of a leaky reservoir to pump hose which stopped the leak, giving up on the rack rebuild and getting a rebuilt one.......My pump no longer wines, but at slow speeds it is VERY hard to turn the wheel. I noticed if I come to a complete stop and put it in park, my power steering is fine. Also backing up in slow speeds in reverse it is fine. I've found if I need to make a turn at slow speeds, if I put left foot on brake and add a bit of gas I get just enough pressure to make the turn. But its barely driveable like this and dangerous even.

So troubleshooting, I suspect the servotronic steering is bad. Do others agree? I pulled the module out. I measured 8 ohms of resistance between the slate (grey wire) and red wire which goes to the transducer. Which seems correct from the ZA manual. Also measure 12 volts between ground and the white/purple wire(with ignition key on but not running). These measurements are taken from the base of the module connector with module removed. Am I correct to assume the problem is in the module? I did find one on ebay for 14 dollars (god i love ebay) so i'm going to pop it in and try when it arrives. But i'm also wondering.....if I get enough pressure with the engine revved a bit.....maybe I do need to send the pump off for a full rebuild? Anything else i'm missing? I left the original high pressure lines in place as they weren't leaking, but wonder if they might be faulty?

 

The replacement Servotronic module might take care of it, since your problem is slow speed loss of boost. Worth a try at that price. Troubleshooting one of those is an unknown quantity. I wouldn't do anything else until you try that. Your pump is probably ok now that you resealed it. Pressure lines shouldn't be a problem if they are dry.

Thank you for the efforts with the steering rack and attempted replacement of the input shaft seal. Too bad it ended with a ZF snakebite. I'm posting a link to the other thread for future reference. Hoping that your rebuilt unit does well. They must have a special tool for installing a new seal.

Steering Rack Input Shaft Seal

Fwiw, I did find the thermocouple connector on my car (as referenced earlier in this thread), tucked under the engine cover. Same DNA.

 

So finally got my power steering working properly after replacing/rebuilding just about every component (seriously everything except pressure switch, and oil cooler was worked on). I totally underestimated this job when I bought the car!

So replacing the servotronic module with the ebay one did nothing. I knew that was too easy and cheap. So what do you do when you aren't sure what is wrong with your Jaguar? Well thats easy, throw a bunch of money at it. So I mailed off the power steering pump to be rebuilt by "the rebuilding factory" that 1 in 19 suggested. They did an OK job I suppose for about 250 bucks including shipping. Beats buying a new pump. "Not possivveeeiiillllll" said in my best German accent.
Next up while I waited for the pump to come back, I figured might as well rebuild the power steering hoses. Took the high pressure side to a hydraulic shop. Made the big mistake of not asking what it cost, I assumed around 100 bucks. Well i got stuck with a 324 dollar bill. Big mistake on my part. I wish I would have shopped around. Anyway they did a nice job and they are good as new, just didn't want to spend that much on them and well.....I guess there is worse things to blow money on?
The reservoir to pump hose I was able to make the ConiTech PSH0419 hose from partsgeek.com for a 2004 Lexus work. Had to trim a few inches off each side, and its not a perfect fit, but good enough and 10% the cost of a new one so I made it work. I'll post a few pics of that. I like that it came with the plastic wrapper protector, seemed better than the foam on the Jaguar one. For the cooler to reservoir hose, just used a small section of Aeroquip 1H103 I had laying around. If anyone needs any of this let me know. Got about 20ft left.

So I finally have good power steering. I'm betting it was just a worn out pump. And my ZF nightmares are not as frequent but substituting "ZZZFFFFFFF" for a four letter cuss word fees nice. I wonder how many otherwise well maintained European cars have been sent to the grave because of this horrible company?

 

And when you bought the car, you said "great, no ZF transmission"!

At least you can resell the Servotronic module for twice what you paid in order to recoup some costs.

I'm sorry. Too soon.

Good news is your power steering system is as new and flawless. As it should be after your great investment.

 

Thank you for the detail in your post. It will come in handy for those in the future with ?'s.