No less than 5 mins after my first post and I already need help!

Yesterday while driving my 1976 XJC V12 I noticed a very faint, high pitched squeling noise coming from the rear right quadrant of the vehicle (drivers side).

It is intermitent and seems to go away when I apply the brake, therefore I am obviously assuming it is something to do with the rear brake assembly.

Would love any initial thoughts or experience if anyone out there has any - regardless if it is with the same model or different.

Cheers!

1976 XJC 5.3 V12

 

moved to the relevant section for you.

Good luck

 

I begin by getting under the (safely elevated) car for a good visual inspection of the brakes. Something might pop out at you.

While you're underneath have a helper turn the rear wheels. You might get lucky and hear the noise....long enough and well enough to trace the origin.

Cheers
DD

 

Hi Doug, I have her up the hoist for inspection but low and behold no one is around to help me!

I'll keep you posted on how it progresses, thank you for your suggestion

 

Just a guess. Have a look at the calipers and pads. Some cars have a tab that scrubs when the pads wear to a certain level. My Tbird did. No help to me, ear challenged, but another warned me. Yup. close to steel on steel!!

Another is glazed rotors and./or pads. Sometimes noise logic just isn't there!!

Carl

 

When were the rear brakes serviced ? It sounds like a stuck piston, so the pad isn't fully clearing the disc. These pads don't have any wear indicators, at least they didn't on my 1980 XJ6 anyway.

 

I had this problem on my 1974 Daimler it took me ages to figure out what it was because it was an intermitant noise, it turned out to be a wheel bearing inner race spinning on the hub, I bought a change over hub, new bearing and seal, you will need to re set the preload on the bearing not an easy job to do the whole assembly needs to be bolted down on a surface table and the end float checked with a dial indicator and the spacer machined until the correct amount of float is achieved.
Adrian

 

Annoying those intermittent noises. If it going away when brakes applied sounds like possible sticky piston as suggested or maybe the disc has a slight distortion and needs replacing/machining.

Often jacking up the suspected corner and gently turning the wheel can help diagnosis if the wheel tends to bind at the same point when turning it.
Sticky handbrake cable can hold the pads closer to the disc as well.

 

Agreed with all so far.

Since its up in the air, look at the rotors. The original rotors were a "sandwich" type, and as well as cracking, exploding, pieces seperating, they squeal, and it goes away with application of the brakes. Replacement rotors are the conventional one piece cast type.

Failing that, the park brake pads will do this. Drive the car, pull the park brake handle about 2 clicks, just enough to apply a SMALL amount of tension on the cables. This usually stops the noise, but does not FIX it. That is a fun task, NOT.

The universal joints on the half shafts NEVER get greased regularly, but that is usually more of a "squeak, squeak" than a squeal.