My shop was working on my car and discovered a leak in the power top hydraulic line. They tracked the leak down and they did refill with red hydraulic fluid. They did tell me that this is the wrong fluid and it can do damage to seals, etc. Should I be concerned? I guess the correct fluid is green. Flushing would be very expensive.

 

Hi Rchuda

I use Royco 756 which is a Red Dye Mineral Oil with excellent Viscosity and easy to get hold of, so you are not necessarily using the wrong fluid just because it is Red unless someone is using Red Power Steering Fluid

Paul (ptjs) is the real expert on this stuff so I would wait till he jumps in to just be sure

 

The correct fluid is actually aircraft hydraulic fluid, it is a very low viscosity, much thinner than typical auto fluids. It's generically called 5606 fluid, and there are two specifications, A and H. A is an earlier fluid, no obsolete for aircraft, and H is a "super clean" fluid. Either works well, use whatever you can find and is cheapest

The cheapest and easiest source I found it was at www.aircraftspruce.com ( or .ca if you're in Canada) This is what I used and it works well: https://www.aircraftspruce.ca/catalo...s66XC5606H.php

 

Here is what came with my car...

 

The viscosity of the Pentosin is about twice what Jaguar specifies, so not an ideal fluid.

 

That is the replacement fluid for the UNIVIS that Jaguar used in the XK8 before about MY2000. The UNIVIS was superseded to CHF 11S. We flushed and renewed the old yellow UNIVIS and used the green CHF 11S as part of a TSB campaign. (TSB 501-33 dated 08/99 amended 04/03)

The XJS used a red fluid that we had in a 5 gallon bucket for dispensing into the convertibles when required. (might have been 5606, I don't remember)

I still have a partial bottle of UNIVIS from the late 1990s but I don't use it in anything.(the parts dept did NOT want it back!!)

 

I recently replaced the convertible pump and rams with new ones from a pump and ram manufacturer in Florida.
The recommended fluid for their system is ATF. They placed stickers on the units that says "USE ATF ONLY".
I called them to ask about using PENTOSIN or any other recommended fluid and they told me that if I used any fluid other than ATF, it would void my warranty.
Top goes up and down very quickly with the ATF.

 

motorcarman is correct. The original Jaguar fluid was Exxon Univis j13 which is no longer available.
If you look for a hydraulic oil that matches mil-h-5606a spec (or possibly 5606h?), that will do fine.

As I understand it, Royco 756 is available in the US and meets that spec. That's a red-dyed non-foaming fluid.

Post-XJS, Jaguar changed hood spec fluid for the XK8 to Pentosin CHF 11S. However, the use of that required a proper flush of the system. Mixing of the fluids seems to often cause a jellying of the fluid causing real problems. I know 2 XK8 owners who had that problem.

There must have been a really good reason why Jaguar never specified the use of ATF. Otherwise it would have been a very easy option common with both the autobox and the PAS The convertible roof fluids that meet the spec have a high viscosity index. And apparently the roof mechanism works very differently and more effectively with this fluid. So, I definitely wouldn't put ATF in the system or deviate from the proper spec.


Rchuda,

If it was my car, I would now fully flush the system through and fill with the correct-spec fluid. There's a very precise procedure to properly prime the rams, if necessary, which I can post here if required. I've never flushed my system so don't know how necessary that procedure may be?

Good luck

Paul

 

I replaced the leaking rams in my convertible a couple of years ago.
Filled them with ATF. The rams on my car operate about 30 seconds 10 times year max.
Not a very arduous duty cycle for a simple hydraulic system.
My guess is that ATF being designed for systems that run continuously for thousands of hours a year will not deteriorate in your rams and pump..
I suspect the ATF will not attack any seals.