I have noticed that during a shortish drive the rear wheels get quite warm to the touch, warmer than the fronts. I think most likely the brakes are the heat source. I don't think the hand/parking brakes are dragging and the shoes don't show signs of it. Less likely but possible is the wheel hub bearings, hopefully they are not running hot! I have removed the rear callipers, cleaned and lubed the calliper guide pins and reassembled and bled, but the rear wheels are still warmer than the fronts after a short run. Is this actually abnormal? I am worried that the brakes might be dragging. It is difficult to tell by spinning a wheel with the car jacked up because there is a fair amount of mechanical drag from the diff/gearbox. What to do?

 

Maybe get onto a sloping road , not to steep a gradient and see how easily it rolls . it may well be that more heat is generated in the driving wheels .Also check tyre pressure's .

 

Thanks for your reply John1949. Tyre pressures are a bit low at 31.5 but they would ahve to be a lot softer to generate the temperature I am getting.

 

If there is meaningful brake drag you can usually tell by simply pushing the car....although you might need a helper with a car as big and heavy as the XJR. He or she pushes, you sit in the driver's seat

Just push the car up to walking pace speed and then let the car roll along. If there's a brake dragging you'll feel the 'grip' right as the car comes to a stop.

Cheers
DD

 

The guide pins fit into rubber bushings.

On this type of caliper corrosion can build
up between the bushing and the surrounding
metal. When this happens, it can squeeze
the bushing causing the pins to drag. Then
the caliper does not fully float on the rotor
causing heat.

The correction is to remove the bushings and
use a rat tail file and sand paper to remove all
signs of built up corrosion.

Reassemble with some silicone grease to slow
corrosion.

 

Exactly my experience with my 97 VDP
In the two years I've owned my blue beauty, the rear tires >wheels are always warmer than I think they should be. I've tried everything both my sixty years of automotive meddling and the cumulative knowledge of this fine forum can suggest.

Found nothing .

The temperature inside the trunk is also invariably hotter than I've ever experienced in other cars, and my conclusion is
The incredible design of the exhaust system, which places the mufflers less than 2 inches from the tires, together with the tail piping placement extremely close to the floorpan.
I also believe that the aerodynamics around there do a great job of preventing turbulence which would ventilate the area.

Many of the suggestions would need both sides to experience the same faults simultaneously, which is somewhat unlikely.
No problems have developed, so I live with it.....and keep a cooler in the trunk