Time to drop the top
Well, its that time of the year again in many places around the world to enjoy your XJS convertible again. It has been tucked away in your garage mothballed for several months just waiting for this season. So you pull the winter cover off and prepare to pull the car out and you unhook the latches, pull on the hand brake, and then press the button but something is wrong. You can hear the motor but the top is either moving slowly or not moving at all. So you lower the brake handle to engage it again but the same results! So the first thing that enters your mind is the possibility that the unit may be on the outs and you may have to call your best friend to ask if he will drive the getaway car after you pull a bank job to pay for the top repair. You know that same friend who helped you dispose of that body once, Now that you have that plan in place and you have his commitment, let's try a couple of other things that may solve the problem.
The first thing to do is to check the fluid on the top pump fluid reservoirs. On an 89 to 93, you will find the unit located behind the passenger seat in the storage box. Now I am referring to this location for cars in the States and in Continental Europe as I do not know if a right-hand drive car is there or it may be on the other side. The bottle sits in clear view on top of the unit. There is a full marker line that you may not see but you will be able to feel it and it located about 3/4 up from the bottom. If the fluid is very low let's say more than half empty, then you have a leak.
Hold on!don't call your friend just yet. While there inspect the tray that the unit sits in for fluid which should be green and is mineral oil. For years so much miss-information has been spread about using transmission fluid rather than the proper top fluid as it was less costly to know some Jaguar dealer parts and service dept staff who tell customers this. Well here are the facts: the green oil is the proper oil to use and it is mineral oil and is the same used in Rolls and Bentley. I know from owning and servicing these cars. The only differences are the labels on the bottles. Transmission fluid causes the seals in the pistons to swell and disintegrate then leak inside the car and when really bad, saturate the rear carpet and ruin it. Ask me how I know this? Wow! What a mess!
For the 94, 95, and 96 you will find the unit in the trunk/boot and is on the right/passenger side behind a color-coded cover and there should be two turnbuckles on the front of it to fasten it to the battery tray. If the fluid is red and low, then you will want to inspect the top pistons/cylinders that are located behind the rear panels where the quarter windows come up and go down. Pull those panels to inspect. They are held on with plastic clips on the top front of the panel and a couple on the front of the panel right behind the doors. Even if the fluid is red and to the full mark I would still inspect as someone may have seen it low and filled it not knowing that this was the result of a puddle on the floor under the rear seat where the pistons fluid will end up.
Please understand that if the transmission fluid has been in the car long enough, the damage may already be done so no one knows. If the fluid is red, the system should be bled and replace with the proper fluid. We can help guide you through this procedure and we do have the proper fluid and if the pistons are leaking, we can help you with them as well. The other problem may be one of the relays also located in front of the tray where the pump motor is.