I write this because information on this topic appears scant and spread out in various forums and i thought it would be good to bring it together here to perhaps assist others.

My problem: Convertible top not working under power. Nothing happening at all.
First fix: Took apart switch on console, cleaned (it was full of crap) and replaced. I could hear the hydraulic pump now running on demand but top still not working.
Next fix: The transparent hydraulic tubing had red fluid in it but also lots of air and the reservoir was empty. Filled system with fluid (O'Reilly's Dexron VI, i knew this would be compatible because it was the same color). Voila! The hood started raising and lowering and after a few cycles performed flawlessly.
Over the next few days, however, puddles on floor, looked a bit reddish...

Leaks are generally found to be due to hydraulic cylinder or pump seal failure. My cylinders were dry but the pump was sitting in a pool of fluid. Others experience says seal failure in pump, so...

Next fix: Removed the hydraulic pump and associated electronics by removing three small bolts two inboard and one outboard (this one hidden by large black connector which i separated). The electronics are attached by the loom to all the relays so i just swung it around.
I removed the black insulated shroud (presumable there for sound deadening), held by two screws to the back outboard side of the pump unit). All the insulation had degraded to a black powder which was mixed with lots of sticky hydraulic fluid. What a mess. Cleaned it up.
Disconnected all hydraulic tubing from pump (and also from rhs cylinder to allow movement of the unit).
Disconnected simple connector and removed two bolts from base of pump to remove it entirely.
Time to dismantle pump. I removed the reservoir and cleaned it out as it was a bit sludgy looking. Do not dismantle the pump head end - it is not necessary, fiddly and could lead to problems of lost ball bearings (ask me why i know this).
I removed the two bolts holding the motor can on and slipped out the armature and brushes etc. The offending article is the smallest oil seal in the world held in the internal side of the pump head by a circlip (removable with small screw driver).
I have ordered seal SKF 527935 through amazon ($15 including expedited shipping). Cleaned up motor internals with brake cleaner. Expect to reassemble next weekend; prognosis good.
The attached photo shows what to expect if anyone else wants to dismantle one of these pumps.

 

Just brought my 1993 XJS home. Top went up and down no problems (was sure to check this before purchase)...now home..top will not go up..I hear no noise whatsoever.. I am thinking fuse/switch..cant find fuse..if you are familiar with location would appreciate the input..thanks

 

I'm not a pro but my dad always said k.i.s.s.. So start with the procedure. Car must be in park or neutral and the e-brake activated. (of course the switch on the pump must be in electric not manual) then check your switch and fuses, just like previously mentioned.

To Texasscot thank you! My power top works but leaks most of the fluid in about a week and I hope your tutorial helps.

 

cAN YOU UTUBE THE REPAIR PROCESS FOR THE A.D.D FOLKS?

 

Did this fix your problem? New to this site, as I found this thread looking for a answer on my 89 power top motor leaking

 

Hi superchargedtr6
Yes, it sure did fix it. Of course the small quarter light window mechanisms then started to misbehave, unrelated to the pump fix, but thats another story
Good luck with your repair. If you've any questions give me a shout.
Graham

 

I have ordered the seal. What concerns me is the two screws that bolt the pump motor to the pump/electrical bracket. They are a standard thread bolt, with no apparent seal whatsoever. They also apear to thread directly into the ouput ports of the pump body. It seems these would HAVE to be a source of a small leak. Did you put any kind of seal/washer on these two bolts?

 

I dont believe i did anything special. To be honest i can't remember the mounting bolts but i doubt the holes would fully penetrate into anywhere the fluid is. Refresh my memory: are the mounting points/female threads in the two protrusions at the base of the pumphead in my photo? If so, they are well away from the fluid channels which are quite small. I think fluid only occupies the tube that crosses the pump head, side to side in my photo, and the gear pump chamber which is the circular moulding behind it.
Hope this makes some sense and good luck with it.
graham

 

I can clearly see into the pump body where these bolts go, that they thread into fluid chambers of the pump body. My leak doesn't appear to be from the motor, which is where the seal I will replace goes. My leak seemed to be from the bottom of the pump, which is where those two bolts go. I also noticed that there was a grimy look around one of the "tee"s. I plan on taking both of them out, and putting some Teflon tape on the threads as well

 

I'll have a look at mine at the weekend and refresh my memory. As i remember at the moment when the seal fails it causes fluid to leak from the clear reservoir through the gear pump and into the motor can, which isn't fluid tight, and it then drains down under the whole assembly. Let me know how you get on.

 

I am kinda stuck till that new seal gets here. Well, on this particular project. This car has been sitting a while. I got it running first, now am sorting through everything. When I first tried to operate the pump, it became obvious it was out of fluid. I kept putting more in, working the top, until I thought it was full. Got to working on it in the next few days, realized the reservoir was down again. Not really much fluid, but it has to go somewhere. The are a couple of tiny holes under the pump bracket, so I am guessing it went through those, but not to the ground. Good rustproofing. Anyway, I took it all out, and even though I haven't pulled the pump motor, the two bolts I'm talking about weren't overly tight, but I can see into the pump body through those holes, and clearly see fluid. Your pictures were a great help, because I did take the pump apart on the reservoir side, and wondered why there were only one of those tiny little ball bearings where it looked like there should be two. DUH......your pictures made me look closer, til I found that it had come out.

 

Its hard to believe but actually Sears stocks XJS parts! Well at least that's where I got my replacement ball bearing. Came in a pack of two I believe, so I still have one somewhere... If you're stuck, and i can find it, I can i send to you. Free gratis and for nothing.

 

That is hard to believe, but you never know....I put the seal in today, and I used power steering fluid. I don't think it will work. My motor is stopping, but my control is working correct, the relays are working correct, etc. Its like the pump motor is overloaded. It actually blew the 30 amp fuse. I straight wired it, but it still stops. I just replaced one of the power window motors doing the same thing. I just ordered some ROYCO 756 MIL-H-5606G as suggested by another site since the Jag fluid is discontinued. Always something with these cars.

 

I would check that the hydraulic pump motor commutator and brushes are clean. Is it possible to bench test the motor? Or maybe the missing ball bearing is jamming the gear pump?

 

I'm not missing the bearing, luckily. I appreciated your pics, as I did drop one out unknowingly, but looked for it after seeing your pics. There are two tiny ones, and two larger ones, correct?

Anyway, the two bolts that hold the motor to the mounting bracket were 1/2" long, so I bought a pair that were 3/4" long, and wrapped them real well with teflon tape prior to re-installation. I feel that the fluid is way too thick. I have ordered some recommended fluid, and plan on dis-assembling the whole mess again, drain every bit of fluid, checking my brushes and all, maybe even seeing if I can replace the brushes? It acts as though it has a thermal limiter much like the window motors. Did you do anything other than clean up your armature and brushes? I didn't take my motor apart, just kinda looked at it, with completely going into it. Looked like there was plenty of wear left on the brushes

 

12/18 update....I ordered a recommended oil substitute. My top now works great! Not only that,but the amperage draw of the motor is so much less, that the rear windows go up and down MUCH faster. That seal, cleaning out the motor, and flushing all previous fluid and replacing with the new worked great. The fluid I bought was far more thin than atf. It seemed thin like marvel mystery oil. Came in a metal can like in the old days. I think it was Hydosol 756 petroleum base hydraulic oil. Thanks for the comments!

 

Hi all,

I didn't even know there was fluid in the convertible system. After reading the posts above, I got the Dex VI and found the pump. I had to craft a home made funnel to fit the hole and brought the levels up to max (there was fluid, but just below min). After cycling the top a few times and filling the tank again, it seems to work very well.

I assumed I would have to take the system apart and replace the actuators, but thanks to you all, it seems to be a simple fix this time. Oh that all the XJS's issues were so easy.

Tony in NM

 

Tony, I hope your top works great from now on. What concerns me though, is where did your lost fluid go? It is a sealed system, much like a automatic transmission. It doesn't "burn" fluid, as a worn engine does, so...... I kept topping my reservoir off, but it wouldn't stay topped off. The fluid ran down in between body panels in some way that wasn't evident. Anyway, I would keep a check on it. Plus, the previous owner had used transmission fluid in mine, but it is much more viscous than what Jaguar intended (I think), and the fluid I bought, that was recommended on this site, worked great. We'll see....good luck!

 

SuperChargedtr6,

I don't know how long ago a previous owner modified the cubby box into a jump seat (years ago most likely), but I doubt the fluid in the convertible pump has been checked on since.

When I opened up the system the fluid level was right on the min mark. I filled it to the max mark and gave the top (hood) a few tries. It worked great, but when down, I could hear something like drips coming from the driver side of the convertible top system. So I presume that if it was a drip sound, it is coming from that actuator.

My puzzlement on this, however, is that if the system was dripping a bit especially after just operating the system, then why wasn't the fluid tank empty?

Tony in NM

 

Mine was at the same point. However, every time I filled it, (maybe 3 times?) it would be down again after the next few days. I never saw fluid on the ground, nor did I see any in the car. I can only presume it is down in between the metal panels of the rear cubby, and the floor panels somewhere. Either way, the seal inside the motor end was the problem. It seems to be holding for now, although I'm not using the car right now, as I have the rear suspension out for a rear brake,rotor/caliper,seals, o-ring replacement. That seal is on eBay for about 14.00, but I noticed last night that convertibletopguys.com sells a more comprehensive kit with the end o-ring, the ball bearings that are part of the check valve, and a few other bits for about 30.00.