Squeaking /chirping rear brake - going nuts!

[rolls 912]

Fine tuning the car post resto. There's this friggin squeaking noise coming from one of the rear wheels - it's driving me postal. Kids are running out on the street pointing at the car yelling look at the car making the squeaking sound mummy!

I've had the rear wheel off several times. Can't figure out what's causing the noise. Here are the symptoms:

squeaks when driving along every time the wheel completes a rotation
Lift the handbrake slightly and the noise disappears / reduces
When you turn a corner the noise reduces
When accelerating the noise reduces
When I jack the car up, the wheel is a little stiff to spin by hand, and it snags at the same spot each time the wheel goes around

The resto:
The disks where machined
new seals for the pistons
I didn't touch the drum pads etc

I've backed off the e brake at the tube and at the star wheel but it hasn't made any difference.

I'm guessing that maybe when I conducted the resto maybe the two rear disks where inadvertently swapped. Therefore the drums aren't matched to the right drum pads causing the noise.

Alternatively, it could be a stuck piston on the disk. I'm throwing this in as a long shot. I haven't done the drive and coast to a stop/feel if it's warm test...

Any thoughts?

[Dan J]

Broken hold down spring on E brake shoe

[ShakinJoe]

Remove the pads and sand them with 60 grit to knock off any edges.

If that does not work you might have a piston problem or a wheel bearing problem. For me it was the wheel bearing.

[DRACO A5OG]

I just rebuilt my calipers. Ever since I swapped to Textars from Mintex my rear pads squeeled like a pig unless I stomp on the brakes. Made me feel very concious and hated it when people look over to see what jelopy was pulling up to their Lexus/Prius.

Whatever

Any who, when I pulled apart the right rear caliper, to my amazement one of the pistons were 20 degrees but on the wrong direction, FREAKIN PO's WRENCH!

Rebuilt & properly set, no more squeels, no noise what so ever!

Check the postion of the pistons, if incorrect use a vise grip, bite litely and turn to 20 degrees.

Jim

[agfours]

+1 on e-brake spring.

I just recently had this problem - learned a couple of things. When the brake gets pulled to hard, it can break the retaining spring that holds the shoe to the backing plate. Then those spring and retaining cup pieces can get lodged between the brake drum portion of the rotor and the shoe. Or, the shoe sits at an angle and the metal shoe chassis strikes the drum as it rotates against the drum where there is closer tolerance.

Also, I am not sure if this is an issue for you or not, but if you have turbo brakes, there are different style retaining springs that do not have the typical 1/2" by 1" spring with the cup and the retaining pin. Instead, the turbo brakes use a combined spring/pin unit which is basically a funny looking spring. If you don't use this type of spring on the turbo brakes, the outer lip of the retaining cup will come into contact with the rotor's inner drum. This will cause the exact same sound as the earlier one described.

Good luck!!

P.S. if you're getting in there and haven't broken these loose in a while, the screws that retain the rotor are commonly frozen, and you may have to drill them out if you can't get them loose with PB blaster / impact wrench. There is a great YouTube demo of a guy drilling these out on a porsche rotor....his machine shop skills were a great lesson on the right way to do it, and worked like a charm.

[rolls 912]

Thanks everyone for the info... This is for an early 901 - drum brakes in the center with disks on the outer. NOt sure if the later cars used the same setup...

Everything is brand new except for the bolts that were plated instead. Just didnt want to pull apart after its being cleaned, plated and torqued etc...

Springs do sound probable!

Wheel bearing - doesnt sound likely as the squeel diappears when the handbrake is pulled up when you are moving but i could be wrong.

problematic Pistons is interesting. Might need to try the coast to a stop and touch the disk technique tonight.

Cheers and thanks again

[Joe Bob]

Ebrake setup is the same up to and exceeding my 83. Ebrake is INSIDE the disc brake.

This ain't no Ford.

[DRACO A5OG]

Hey M,

I miss my Found On Road Dead '66 Stang Cab :-(

+1 same drum inside disc rears.

If you don't want to remove the calipers off the arm then with wheels off, spray it clean, the with a light and sticking your head in, check where the notches are of the pistion, I would check both rear. Mine was very apparent. Smooth on one side and then the proper notch location of the 20 degrees on the other

[rolls 912]

Originally Posted by DRACO A5OG

check where the notches are of the pistion, I would check both rear. Mine was very apparent. Smooth on one side and then the proper notch location of the 20 degrees on the other

Hey what are the notches - is this the notches in the star wheel that actuates / adjusts the drum? Or is this the piston for the disks.. never seen a notch on the piston? cheers

[aldente295]

It's on the backside of the piston. It's pretty subtle on the backs; a much more pronounced lip on the front.

I lean more to the ebrake as the cause tho. If the piston is incorrectly aligned, you hear squealing when you _press_ the pedal, not the other way round.

[DRACO A5OG]

+1 if you here a squeel while driving and not on the pedal then I must default to inner Drum Brake Spring or retaining plate must be loose or off.

Jim

[rolls 912]

I jacked the car, carefully put the car in gear and Listened for the squeal. Couldn't workout where the sound was coming from. Used the old piece of pipe up to the ear trick. Worked out it was the backing plate holder was slightly bent and it was rubbing the inside of the disk. Thanks for all the help guys. Bring on the weekend!