Chirping Sounds Driving Me Nuts!

[Oliver Klosov]

Does anyone else have soft chirping sounds coming off, what I believe, to be the brakes, at low speeds? I have a '79 SC with just 56K miles on it. Will just the length of time, the age of the car, take the tension out of the caliper springs? Is there something else that could be causing these noises?

[SWISSMADE]

Hi, you could try putting a light chamfer on the leading edge of the brake pads, or try changing the make of pads. Some mechs put a thin layer of very heavy grease (or copper grease) between the pistons and backs of the pads, it's supposed to make a difference....eliminates wind noise or something. I've never found a cure, sometimes they do sometimes they don't ...seems weather dependent.
BTW, original pads are no guarantee that they won't squeak or squeal.

Cheers, Mike

[Mo_Gearhead]

Caliper Springs? Brake wind noise? I need to read more! My knowledge of brakes is really lacking something???

[Gunter]

Open the Bentley SC Repair Manual, read from 460-1 to 470-11 and you'll understand a lot more about your brakes.
Lift the car securely, take the front wheel off, press the pads open with large channel-lock pliers, remove the pads (Make sure they move freely in the calipers, file if necessary) check the 20 deg cutout alignment on the pistons (460-6) Check the dust boots.
If everything looks good, smear some brake goo between pistons and the back of the pads, clean everything an reassemble.
Pay attention to the pistos. If they are seized, or don't move freely, it's time for a rebuild.
This is the time to check/adjust play in the front bearings and top up the grease inside the Stouffer cup.

[rdrr]

Does the noise occur when you are on the brakes or just at low speeds? I get some chirping going over bumps at very low speeds that I believe could be due to worn suspension bushings - but I haven't looked into it yet to confirm.

[2ndTARGA]

OK here's a possibility..........

I had the same symptom - loud chirping noise when driving - seemed to be in the suspension or a wheel bearing - couldn't pin it down.

Finally I figured it out, it was the dash blower motor bearings. As soon as I'd hit a certain speed the fresh air coming through the cowl inlet would cause the blower fan to rotate at low speed even though it was not on - causing a chirping that seemed to come from outside the car. I figured it out by turning the fan switch to high - and the noise stopped. Turning off the fan resulted in the same chirp coming back as the fan slowed to a stop.

I've yet to take it apart and lube/replace the fan bearings, but I no longer wonder if a wheel is going to fall off.

Ron

[ToddM]

I has a squeaking noise once for a few weeks, but it was a gerbil I forgot about

[Por_sha911]

Make sure you don't have a frozen caliper.

[stlrj]

I had the same chirpping that was driving me crazy for years until I jacked up my front end one day and found my left front A arm was loose up front where the three 17mm bolts were just hanging on their inserts that had broken off.

Take a look at the illustrations on this thread and you might see how one of the 17mm inserts has broken off it's welds which is pretty common since they're only tack welded at two points.

Any lowered 911 that has bottomed out on the front A arm cover has probably broken some insert tack welds.


Ran over curb; front end damage



Cheers,

Joe

[kach22i]

Originally Posted by stlrj

I had the same chirpping that was driving me crazy for years until I jacked up my front end one day and found my left front A arm was loose up front where the three 17mm bolts were just hanging on their inserts that had broken off

I followed the thread links, several of them.

Clear here:
Ran over curb; front end damage


Does anyone know the torque spec?

[Oliver Klosov]

I have determined the chirping to definitely be coming from the brakes. When I hit the brakes the chirping stops. When I release the brakes the chirping is gone for a minute then returns. I hit the brakes again ant it stops. Could my brake pads be glazed? What else might cause this? Thanks. -O.K.

[john70t]

There could be a little runout in the brake disk-fixed by getting them turned.

Is there any resistance in any one spot while spinning it? Wheel bearing/ball joint play?

[Wil Ferch]

Like someone here said, it is likely the slight amount of backlash that is taken up when you apply the brakes ( and no squeal) vs. when free-running and you hear the squeal. Some folks use the brake pad "goo" that gets applied to the backside surface of the pad before you re-install...but I've found these messy and tends to take out the dust boots later as you remove old pads. I usually do a couple of things that tend to help.

- chamfer the edges at a 45 degree angle ( slightly, don't go nuts) with a file or rasp. Do all sides. Make sure the 20 degree caliper puck orientation is correct.
- add "anti-squeal" shims made of an Aluminum/acrylic composite, and has a one-sided adhesive that allows it to stick to the backside of the pad. I found this usually as a "Help !" product line from Colmar, Pa...found at your FLAPS. If you're lucky you can find this cut-to-size for your particular brakes but I've lately only found the big sheet that you cut up with a scissor.

Works well....

- Wil