Top goes down OK. However, will not raise without help. Assist the pump about half way and then the pump raises the top to close position.

 

Low fluid in the pump?

 

Make sure that the brass 'T' valve on the side of the pump body is fully closed (clockwise). Many a pump has been replaced when the valve was the problem.

 

Fluid level full and T fitting is fully closed. Suspect either the motor or pump not up to full output power.

 

Is this a 2005 model?

Does the pump have an aftermarket pressure reduction valve or resistor? Post a picture of it if you are not sure.

Also, what color is your fluid? It is possible the system was refilled with the incorrect fluid.

 

Year is 2006. Fluid was low and topped off with Pentosin CHF 11S. Top was modified for manual latch release.

 

What a shame! You should get it fixed.

Gus
www.jagrepair.com

 

Did the problem with raising the top follow soon after converting to manual latch or at a later time? Check the port caps where the latch hoses used to be attached to the pump. Be sure they are snug (just snug is enough) and of the correct type. See link in my sig. line below.

 

Here is the sequence of events. The top operation totally failed. Car brought to Jag dealer for evaluation. Advised that Pump needed replacement, two windscreen switches needed replacement, hydraulic hoses needed replacement and communication between SLCM and top operation was suspect. They quoted $12500 for repair. I ran out of the shop. Having some elec. and mech. experience I performed my own modification. Removed hoses to windscreen and plugged pump ports. Disconnected pump motor from top circuit and connected to remote switch via fused circuit. Removed pump relay from top circuit and connected to remote switch. To lower the top, close the power switch to energized the pump motor and to raise the top, energized the motor and close the relay. Now the top goes down OK but on the up motion, it raises several inches, needs "help" until about half way and then the pump takes over and closes the top.

 

$12,500. yikes! Good for you that you have the skills to go another way.

Your symptom suggests that the pump is not quite making enough pressure to get past the "hardest" part of the cycle. It is possible that a prior owner has reset the pump's internal pressure control valve to reduce peak pressure. This would not be visible externally as is attaching an external relief valve, but it accomplishes the same thing. See "zero-cost pressure reducer" in my sig line.

The motor and the pump are both of pretty bullet-proof design. I've never seen a credible report of a pump failure. The motor, if it gets in trouble, will probably not run at all and may blow fuses.

BUT ... all that said ... a little lubrication of the moving bits in the top frame may be all that you need to get past this. Worth trying that first.

Good luck.

 

Dennis, I do appreciate your input. I will lubricate the frame parts. Assuming the pump is not putting out enough pressure to the ram circuit, can it be increased by turning the adjustment screw on the valve (lower right valve)?

 

Before you start pulling thinks apart try the lubrication but lubricate the outside shafts on the rams with WD40. The Pentosin CHF 11s is a produce that does not gel unless the previous owner introduced another product to the system.

Because your car is a 2006 I would think the pump is ok however, anything is possible. I am thinking that the previous owner did not operate the roof when the hoses failed and it just got dry.

I am a little concerned about the switches in the header not working and thinking they have been tampered with. To date I have yet to see any of them fail. My guess is that they crossed the plugs in the header.

 

If we have no luck with lubrication ... and if the valve had previously been reset ... then adjusting it for more pressure will be a good next step. One flat at a time (1/6 turn) would be a good increment; it bumps the pressure by ~ 150 psi. I would not adjust a valve that had not been reset earlier, since the factory setting provides way more pressure than should be needed. It's actually the valve on lower left we would work on (that may have you scratching your head; I'll explain if we get there).

You will be able to tell if anyone has been in there. A locking dimple on the side of the valve will have been drilled out if so.

 

Lubricated all the top linkage. No improvement. Raised pump pressure as recommended. No improvement. Only remaining possibilities are, poor function from motor/pump or damage to top linkage from manual operation. However, top goes down OK and up with minor manual assistance. So, found a used pump on ebay for under $200 and made the investment. Stay tuned.

 

That's a great price for the pump.

So you found an internal pressure valve in the pump had been adjusted earlier? What change did you make?

Not sure I understand about "possible damage to the top linkage from manual operation". What's up there? (Edit: If you're thinking about how you've been manually helping the top to raise ... very unlikely you would have been exerting anywhere near enough force to be a cause for concern.)

 

The dimple on the valve (left) was not drilled out but the adjustment screw easily turned. I rotated it about 1/4 turn clockwise. If someone (maybe the knucklehead Jag dealer tech) attempted to lower the top manually prior to turning the T valve some linkage parts could have been damaged. This is the tech that said I needed $12,500 worth of repairs.

 

Somebody really screwed the pooch on this one. I don't know how anyone loosened that screw without drilling the dimple, but we probably don't want to know.

You really did get a great price on the pump. Guys have spent lots more.

Rather than swapping everything out, one approach would be to pull one of the control valves from the replacement pump (one stamped "110") and try it in place of the valve that's been messed with in your current pump. Just a thought ... less disruption ...

Good luck.