For quite some time now, perhaps 1 in 50 brake applications would result in your typical brake squeal emanating from the front of the car. I recently realized, after a short trip involving brisk stop/go driving (I was in a rush), that brake squeal was correlated with brake heat buildup. They squealed worse than ever during this short trip, which disappeared completely when the brakes cooled down. Recently, the frequency of squeal has increased, and is still correlated with degree of brake usage.

There is no warning about brake wear in the message area. I don’t have a code reader so can’t pull them. I don’t know when the brakes were last serviced, but can say for sure: not in the last 12,000 miles. The car currently has 80,000 miles.

I’ll be bringing it into the dealer shortly. Any advice to give so they don’t take me for a ride (metaphorically)? TIA!

 

I'd put money on any dealer immediately recommending new pads and discs ...... even before the vehicle gets in the workshop.

Worth removing the front wheels yourself to check pad wear and disc condition before you take the vehicle in. The squeal could be wear, a build up of brake dust or a sticking caliper.

As the brakes haven't been serviced to your knowledge in the last 12k miles, it could be time for a brake fluid change. This is recommended every 20k miles or 24 months.

All of this is well within the capabilities of a DIY'er and many members (myself included) do all their own brake servicing. It can get expensive at a dealer or independent.

Graham

 

For the cost of the dealer telling you that you need new brakes you can replace all 4 corners with new rotors and pads. Very easy job!

I used these..

Full Kit Drilled Brake Rotors and Ceramic Pads 1998-2003 Jaguar XJR,XK8,XKR | eBay

 

Thanks for your replies. I'm not a D.I.Y. unfortunately. I still don't understand why the noise only appears in limited circumstances when the brakes are warm/hot, and why there's no warning message - which supposedly appears at 25% pad life remaining.

 

As far as I know, these pads are not equipped with a wear sensor, so I would not expect a message for worn pads. The only message would be for low brake fluid in the tank on top of the master cylinder. The 2 are not entirely unrelated, but you should check the pads independently. The easiest would be to locate a mechanics mirror (small coin size mirror on a telescopic arm, a few $ at the parts store) and check the pads for yourself through the spokes of the wheels (the wheel does not need to come off). You might want to check some pictures online, e.g. eBay or parts catalog, to see how the caliper is laid out and make it easier to get your bearings. The alternative is to somehow wedge your phone in there and get some pictures. Check both sides of each of the rotors.

For rotors, the cheap check is to run your finger along the radius (once cold!) and check for a lip at the outer edge. The more that lip is pronounced, the more wear. The true answer is of course to measure the thickness with a caliper, and compare it with the minimum thickness that is usually stamped on the rotor itself.

The short answer is that I would try and get a sense for the condition of your brakes before a visit to a shop.

Also, just to throw it out there, noisy brakes can be a pain to work through. Sometimes, if they are still in decent condition, what they need is to be re-bedded. You should read about it yourself, but it involves braking from highway speed to low speed a few times to build some heat and re-set the pads to the rotors.

Best of luck, keep us posted.

 

[QUOTE=fmertz;1555274]As far as I know, these pads are not equipped with a wear sensor.

I stand corrected on that - confusing with another car I owned.

Will keep you posted.

 

Braking generates a lot of heat. Heat causes expansion and clearances close up.

Without going ito the variations between standard and Brembo brakes, when you press the brake pedal the piston comes out of the caliper and pushes the pads into contact with the disc. The caliper body moves on large diameter pins and the pads move on small diameter pins. If any of these components bind when hot, you'll get squeal.

The pad wear indication has already been covered.

Graham

 

Bob, to echo what Graham just said, squeel can happen from brake pads wear indicators or from vibrations in the pad itself. Since this is heat related I'd bet on the latter cause.

I admit I forget whether it is a shim or special grease behind the pad, but one or both reduce brake screech. I'll leave it to those smarter than me to explain it further.

John

 

Award for prognosticating abilities goes to Moderator GGG.
Time to get to know a good local indy..

 

To give you an idea of pad wear, OE pads have 11 mm of friction material.

I don't like to run mine much below 50% wear before changing.

Graham