Rear Suspension Low Warning - Handbrake Malfunction

[AlanC]

Hello Guys (and Gals?),

I had an interesting warning come up on the XJ4.2 Sport, with 4 passengers in the car: "Warning - Rear Suspension Low" (or words to that effect). Warned passengers of weight issue (Ho, Ho!) and got them out. No effect - warning still there. Then worked out that the warning came on when I was reversing out of our drive (with passengers), so could be electrical handbrake stuck on, causing rear radius arms to "tuck up" and create warning.

Got underneath rear axle (car on axle stands, folks) and checked electrical actuator on handbrake: Sure enough, mechanical linkage was seized (despite car having history of Jaguar main dealer servicing until my ownership - you see why I do my own?!). With a bit of "Cold Setting", as we engineers call it (or judicious bashing with a Birmingham screwdriver, for everyone else) and a good squirt of penetrating fluid (careful of brake discs) into the whole mechanism and linkage, I got the rear handbrake working properly. Then lubricated all joints / sliding parts properly.

Always check that the brakes are adjusted, after this job. Brake on: wheels locked; brakes off wheels free. Easy Fix.

Good luck.

[robv12]

Alan see my other post re a handbrake warning on our car, did you get a "parking brake malfunction" warning as well as "suspension low" warning

I have to say at first test the park barke on ours appears to do what it should, I do not have the car with at this moment in time as it is still in use and has gone off for the day with the current Mrs J!!

[barrywi]

If your wife is the "current" Mrs J, are you planning on trading her in?
My car had a kerfuffle with the trip computer when the range just kept going down to zero and then stopping, resisting all efforts to re set it.
Battery disconnected for 10 minutes ( make sure you have the radio code!!) and all ok now .
The problem I had when I got the car ( air bag warning light on now and again) which I thought I had cured by keeping the battery volts up ,has returned however. I will post in the appropriate section when sorted.

[AlanC]

Rob,

Yes, the handbrake "parking brake malfunction" did come up (I seem to remember) but only once I had moved the car.

That helped lead my thinking towards being the brakes causing the supposed suspension fault.

These advanced technical things are a wonder but, goodness, they don't half complicate life.

All earlier to this fault arising, the previous owner had had a fault with the air suspension controller, in the boot well (well being the apposite word). On one occasion, I found about 3 inches of water in the boot well (another half inch would have trashed the replacement controller). A series of 6mm holes in the boot floor now prevent build up (doesn't matter what you do, the boot lid seal will leak under torrential rain), so, having fixed the water vs. suspension controller fault, I knew that the water-in-boot-well fault should not be the cause of the low suspension, this time. There is another thread on water getting into the boot well, so it is probably more common than some may think. As I said, a series of 6mm holes does the job (simple solution that works is always the best) and doesn't cause water to get sprayed back up into the boot.

Alan

[robv12]

cheers Alan, car fixed with a battery disconnect and reconnect, all appers well, it will be in hard use tomorrow, so we will see