I have a 94 V12 LHD convertible with the Teves system. In the 16 years I have owned the car, the pedal effort has always been high, much higher than any of the other Jaguars I've had. Recently I had new tires out on, and while the wheels were off I had a look at the brakes. The pads on 3 of the wheels had about 1/3 remaining, while the right rear was nearly new thickness pads.

About 8 years ago I had replaced that caliper and flex hose, but I can't remember why I did that now. A week ago I rebled the system using the Teves procedure mentioned here and I did get a significant amount of air out of the right rear caliper. We then took the car on a 2000 km trip to a car show, and the brakes don't feel any different. I'm not actually sure if the brakes are now working on all 4 wheels or not. At certain speeds under heavy braking it will pull to the left a bit.

The right rear rotor did have signs that it was functioning, there is wear on the rotor and a clean surface, its not like the pads have not touched the rotor. Without removing the wheels and looking through the spokes, everything appeared normal.I can't remember the brand of pads I used, but they would be semi metallic, not ceramic.

The other thing is I obtained worse fuel economy than I usually do on this run. I can typically get 11.5-12 L/100km and this time it was closer to 14.5 L/100 km. The car seemed thirstier than it should. It may be unrelated, but it might be dragging brakes? I didn't smell that characteristic smell of burning brakes or see any evidence of heat damage on the rotors though, so it might be something else. The surfaces of the rotors look like normal brakes.

My main question is a heavy pedal effort and a good shove on the pedal needed to bring the car to a stop normal operation of the Teves system? If not, where should I be looking?

As a second though, I was thinking I should probably replace the pads just to make sure they were not the cause of the problem. Is there a favourite/recommended pad out there?

 

Jagboi64,

A couple of thoughts:

- A very slight pull to one side under heavy braking doesn't sound like the Teves ABS valve block malfunctioning. When the valve block malfunctions, the car will dive violently to one side. So I suspect a slight pull is something else in the brake setup or even tyres or suspension.

- If you've now got unbalanced pad wear on the rear brakes with one down to 1/3, I would be minded to change them. I always like to have evenly-wearing pads on both front and rear. But remember, DO NOT push back the pads without connecting a tube to the bleed nipples and loosening them first. You must ensure that you don't push fluid back up the pipes to the valve block.

- In my experience on the outboard XJS, if you've got a rear caliper that is sticking on, you'll feel heat buildup just by holding your hand to the rear wheel.

- The front-end braking on an XJS is so good that the rears seem to do much less work. This means that the pads don't wear out very fast, but the calipers can end up sticking through lack of use.

- I would unbolt the rear caliper (remember don't push fluid back!) and check the free movement of the sliding pins and also the caliper piston. Grease up everything and reassemble.

Good luck

Paul

 

That sounds like a good plan of attack, thanks for the suggestions.

The car is stored for the winter, so it does sit for 6 months with no use. So it is entirely possible that a caliper is sticking and/or corroded.