Yep, 50 miles, maybe even more.

Says she felt no resistance. This was last week. Yesterday, a loud screeching noise began coming out of the left,(she thinks), front tire when applying the brakes. But only when pressed hard, not when pressed lightly.

I took it out later for a short spin but no sound, so I have three questions:

1. Could the screeching be related to driving with the parking break on?
2. Is this only happening after driving for awhile and the brakes heat up?
3. New front brake pads were put on about three weeks ago. Could this be the problem? I would have thought I'd head the nosie when I drove it if this was the case.

Car is 2006 XK8, 29000 miles. Thanks for any help.

 

1. Possible but the parking brake is an entirely separate mechanism from the rest of the brakes and it is only on the rear. Can you confirm for sure whether the noise is coming from the front?

2. If it is one of the normal brakes and not the parking brake, then this is also possible.

3. If the back sides of the pads were not adequately greased or if you had metallic pads installed then the new pads may be the cause.

If you have not done anything to bed the brakes you might try a few hard stops.

It's best to get up to speed and brake hard but not come to a compete stop. New pads can transfer material to the rotor when hot if they aren't moving which can cause vibrations.

 

Took it out and did some hard breaking. No noise yet. Don't know what type of pads were put on. If continues, can I grease them myself to see if that's the problem? Know nothing about brakes.

 

Tip:1
never tell wife where the keys are!

 

Oops!
XKR 2000 92000mi.

 

My breaks always wear out faster when my wife drives the XK. She either has her foot on the gas hard or breaks hard. She doesn't bother to remove her foot from the gas when she sees red lights ahead of her until the last possible second.

 

Don't grease the wrong side!

 

The Parking Brake is a pair of shoes (item 3) operating inside each of the rear discs. When the brake is applied, they expand and grip the inside of the disc:



Under normal circumstances, they don't wear out because the wheels are never rotating when the brake is applied. Fifty miles with the Parking Brake on and they will be toast. It will be remarkable if the friction linings aren't completely worn away down to the metal shoes.

The rear discs should be removed to examine the Parking Brake shoes and the inside face of the disc. This incident could have wrecked the discs.

If there's a screech coming from the front brake, it's totally unrelated to driving with the Parking Brake applied.

Graham

 

I may not have described the action of the Parking Brake shoes clearly.

The shoes (item 16) expand against the inside (arrowed in red) of the Brake Disc (item 2) to prevent rotation:



This is the Brembo rear brake but the standard rear brake has the same Parking Brake setup.

Graham

 

Take the keys away before someone gets hurt.

 

If he took the keys away the first person to be hurt would be him.

 

The parking brake is a completely different system from the foot brake. No connection whatsoever, as others have said.

If your wife drove 50 miles with it 'on' and noticed no resistance, it might have been only partially engaged, not enough to cause real damage. Typically under such circumstances, partial engagement of drum type brakes will create enough heat to cause the drum to expand and partially lose contact with the shoes- what used to call 'brake fade' in the old days.

Set the brake fully to see it still holds properly. If not, possibly it can be adjusted to regain full function.

The noise from the foot brake can be pursued separately.

 

I'm not surprised your wife didn't feel any resistance. I never normally put the handbrake on, because it's so awkward to do, but when others have done so in the past, e.g. when I collect the car from a garage, I am amazed how the engine just powers the car on regardless. So far I have always noticed the red warning light within a few yards of driving off, but certainly there is no resistance to speak of.

 

If you know nothing about brakes, be careful messing with them, esp. the way she drives. If you're mechanically good with repairs, then read up on pad replacement first. There are sections on this forum and many great You-Tube videos on how to do it. Hardest part of the job is getting the car up on stands and the wheels off. Noisy pads are due to microvibrations as the pad grips the rotor. Usually a small amount of high temp molly grease on the pad "ears" where they slide and on the back face where they contact the pistons will prevent noise. I've been using a non-squeal product on the back of the pads that I found on bavauto.com and it's been working well on my ceramic pads (Jag,BMW, and Volvo).

 

Can applying the grease be done without taking the pads out? If not, I've got a friend who's good with brakes

 

Unfortunately no, you will need to pull them out. The grease goes on the back side where the piston makes contact and the edges where the pad rests against the caliper.

 

I'd hold fire on putting any grease anywhere. Find out what's wrong first.

 

Right, there's no need to panic. See how things go for a while, and if there's still noise hopefully you, your friend, or the dealer can take care of it pretty easily.

 

This may or may not be an issue in your part of the World......

...... a small stone from "loose chippings" on the road can get stuck between the Brake Disc (item 1) and the Disc Shield (item 7):



Being in contact with the rotating disc and fixed shield, it sets up a terrific metallic scraping noise as if something is about to collapse. Sometimes the stone will get thrown clear, other times it needs the wheel taking off to be able to punch it out.

Graham

 

That certainly was the noise. I heard it inside the house!! Taking the wheel off anyhow to clean with Brakeleen. Thanks, I'll look for something like that