Hi all- first let me say I read all of the related threads on this issue but haven't found one that describes the issue I'm having exactly. Since the end of last summer the top has been opening/closing slower and slower. Now it's finally stopped working all together and is in the up position.

1) I've checked the fluid level and it's at the max fill line. There are no leaks under the car, so I've ruled out leaking fluid.

2) When the top was working (slowly) the latch would raise and lower but sometimes have a hard time pulling the top shut completely.

3) When it was working, it didn't seem like one side or the other was sticking or closing at a different rate.


I haven't tried to open it manually as it says in the handbook it could damage the linkage (but somehow closing manually is ok?)


Would flushing the system be a good first step? Could it be an issue with the motor? The battery in the car is also older. Starts fine every time as I keep it on a Ctek but not sure if this could cause the problem?

Any help is appreciated.

 

Have you been operating the top with the engine running? If yes, the battery is not likely the fault. The fluid should be green.

 

Yes, running. The fluid looked more blue to me when I checked but I will check again. Are we talking a coolant - color green?

 

The oil is Pentosin CHS 11F, and it could look blue through the plastic. It's a typical hydraulic fluid.

 

Howdy folks:
Am I correct that we can rule out the petcock valve not being fully closed?

 

Seems to me that you have low pressure in the hydraulic system. Would not guess that the trouble is caused by battery issues, but giving it a try with another one is easy to manage.
assumed there is actually no leak and the relieve valve is properly closed i would have the pump itself or the motor under suspicion.

Therefore I would have the pressure checked, should be around 1300 to 1500 psi while roof switch is activated. if the pressure ist low next step could be an independent power supply to the pump/motor. if there is no improvement than you should have the pump/motor performance checked.

 

I would check the battery and with a little luck that would fix the problem. Many times a sluggish roof operation is due to the rams no being lubricated. This could be resolved by applying a little WD40 on the shafts when extended. This would also apply to the latch ram and linkage. As for the fluid if lubrication does not help I would drain and refill the fluid in the tank. It could be contaminated.

The motor/pump is designed a little like a rotary engine and it compresses the fluid using a piston action unlike other pumps.

Try doing the simple things and see how it goes.

Link http://jagrepair.com/HydraulicFluid.htm

 

Thanks, is checking the pressure something I can do myself?

 

Ok, sounds like a good place to start. Is a there a diagram showing where the rams are located/where the lubrication points are? Assuming extended is in the top-up position.

 

I think that can be ruled out, as I've never had to manually operate the roof so I've never touched the valve before - and it was working properly up until the last few months.

 

should be easily done in a shop with hydraulic equipment. you just need a manometer with a t-piece and suitable fittings. should be connected between one of the hoses and a pump fitting.

 

Just remember the pressure will exceed 1600psi however, I would do the lubrication.

 

doing the lubrication is a good advice and should have been done anyway. but the effect its a bit overestimated if you assume that the amount of increased friction will cause a stalled convertible top.

 

Moving the roof is a real task when it is horizontal hence the reason for the way the linkage is designed. With a little friction the movement would be restricted and the reason for the lubrication. With that being said you also need to consider fluid contamination that could restrict the flow in the system. Changing the fluid would also be a good idea. This system has valves, orifices and a rotary like pump that is bidirectional that any contamination could block.

 

Just wanted to update everyone. Very grateful to Gus, who took the time to give me a call and explain how the system worked. I was able to lubricate the 2 rams for the top today, and it worked! The top went down smoothly and quicker than it did before.

However, it still struggled to latch when putting it back up - so lubricating the latch ram is next (I ran out of daylight today).

Gus, to access the latch ram, do I need to remove the fabric headliner on the windshield frame, or is it easier to access it from the top by removing the black header around the latch?

I will most likely replace the fluid in the system as well in case both problems were causing the top to not function.

 

To get to the latch ram you will need to have the roof open and the cover to the latch removed. Use this link and go down to the 10th photo and it will show you how to get the cover for the latch removed.

Link JagRepair.com - Jaguar Repair Information Resource

 

Thanks that's helpful - will give it a try in the AM. Looking at that photo, where would the best lubrication points be?

 

Once you remove the cover you will see a small portion of the ram and most all the linkage. I would suggest that you open the petcock at the tank and manually open the latch and you will see the ram for the latch. Lubricate it and the linkage associated with it.

 

Finally had some time to get back to this project - lubricated the main rams again, and was able to get the latch cover removed. I lubricated the ram as well as the linkage, and top was able to latch on it's own after doing so. The whole process is now faster as well, all thanks to Gus!

I will most likely still replace the fluid, but have decided to wait until springtime as there's only another month/6 weeks of top-down weather left unfortunately.

Now that I know how to access everything, I think all 3 rams could be lubricated in about 30min, so it's something I will probably do each spring just to be safe from now on.