April 21 - May 6, 2017: Replacing the convertible top cylinders . . .
Read MoreA few months ago, I tried to lower the roof on the XJS. The first clue I received that something was wrong came in the form of a strange noise from the convertible top pump motor. It made a noise that seemed to suggest the system was low on fluid. But the roof lowered the way it was supposed to do, and I didn't give the matter a second thought.
That is UNTIL I saw a trail of red fluid under the right side of the car after I pulled out of the garage. So I've got a leak somewhere. But unlike the incident with the XK8 last year where leak seemed to be coming from the trunk, this leak appeared to be in front of the rear wheel. This made me think I had a problem with either an hydraulic line to the right hand top hydraulic cylinder, or the cylinder, itself. There is only one way to find out.
The convertible top system on the XJS is much simpler than the nightmare installed on the XK8. Even so, the lines and cylinders are located near the rear quarter windows, which means the back seat and quarter trim panels need to be removed to access the cylinders.
Today seemed like a good day have a look at it. Time to break out some tools.With the trim panel removed, I also have access to the rear speaker. I noticed a speaker problem a few months before the roof issue surfaced. No matter what music source I would use, (CD, USB, or radio), it sounded awful. So as long as I was in the neighborhood, I decided to replace them as well. The speakers are accessed by prying the plastic retainers away from the speaker carrier with a trim tool.
Now it was time to replace the top hydraulic cylinders. Like the rear speakers, the top cylinders were also original to the car. In this case, it's always a good idea to replace both cylinders, (if one 22-year-old cylinder failed, the other one may not be too far behind). The OEM units are obsolete from Jaguar. Thankfully, reproduction units are readily available, (and much less expensive) in the aftermarket.
With the new cylinders in place, the final step in the repair was to fill the top reservoir (located in the trunk above the battery), and bleed the system.
It's not uncommon for convertible top hydraulic systems to use something like automatic transmission fluid. This system, however, calls for "Univis J13" hydraulic oil which, like the top cylinders, is obsolete from Jaguar. Hydraulic oils vary quite a bit in terms of viscosity. Using a thicker fluid can cause damage to the pump mechanism. It took some searching according to the original specification. But I found a replacement fluid: MIL-H-5606-A, a military grade "super clean" hydraulic oil used for aviation applications. Like the rear speakers, this fluid is available at a very reasonable cost, (I paid $9 for a quart).