Warped rotor?, Have now confirmed it's warped. Options

[john77]

About a month ago something in the rear of my car started making this high-pitched squeaking, metal on metal noise when I was reversing. Not constantly, but like something turning was binding and releasing, binding and releasing. I only had the rear bearings replaced 6 months ago, so i hoped it wasn't that.

With the car up on stands and the rear wheels removed I've isolated it to the driver's side rear wheel. If I turn the rotor by hand it rotates freely and then gets really hard to rotate, and then gets easy, and so on.

My first guess is that somehow I've warped the rotor. Does that sound right? I've never tracked the car, but I do ax it. Or could it be something else? I have the 5 lug conversion, so I believe they're off a 911.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i2.photobucket.com-17027-1439069310.1.jpg)

[stugray]

Stupid question, but why cant I see a E-brake lever arm in the pic?
I dont see the cover for the outer adjuster screw either.
Rears requires you to turn the adjuster screw to retract the pistons.

From the limited pics those look like front calipers.

[john77]

Stupid question, but why cant I see a E-brake lever arm in the pic?
I dont see the cover for the outer adjuster screw either.
Rears requires you to turn the adjuster screw to retract the pistons.

From the limited pics those look like front calipers.

They're rear 911 m-calipers, so no e-brake. Sorry, completely forgot I asked about the calipers in another thread, not this one.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i2.photobucket.com-17027-1440700511.1.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i2.photobucket.com-17027-1440700511.2.jpg)

[stugray]

Stupid question, but why cant I see a E-brake lever arm in the pic?
I dont see the cover for the outer adjuster screw either.
Rears requires you to turn the adjuster screw to retract the pistons.

From the limited pics those look like front calipers.

They're rear 911 m-calipers, so no e-brake. Sorry, completely forgot I asked about the calipers in another thread, not this one.

Then you should be able to get the pistons to move using a small C-clamp.

I just rebuilt a bunch of 914 Early front calipers to install on my race car in the rear.
It is very simple and if you dont feel the need to replate (or paint) the calipers, you can rebuild a pair in an afternoon.
It takes longer to take them apart and get the pistons out then to put the new parts in and put them back on the car.

[john77]

Stupid question, but why cant I see a E-brake lever arm in the pic?
I dont see the cover for the outer adjuster screw either.
Rears requires you to turn the adjuster screw to retract the pistons.

From the limited pics those look like front calipers.

They're rear 911 m-calipers, so no e-brake. Sorry, completely forgot I asked about the calipers in another thread, not this one.

Then you should be able to get the pistons to move using a small C-clamp.

I just rebuilt a bunch of 914 Early front calipers to install on my race car in the rear.
It is very simple and if you dont feel the need to replate (or paint) the calipers, you can rebuild a pair in an afternoon.
It takes longer to take them apart and get the pistons out then to put the new parts in and put them back on the car.

Thanks Stu. I think I'm going to go the whole way and get them replated with zinc - my friend runs a shop so he said I can throw them in with his next batch of stuff. Are the 914 fronts the same in that you need to use compressed air to get the pistons out?

[stugray]

Thanks Stu. I think I'm going to go the whole way and get them replated with zinc - my friend runs a shop so he said I can throw them in with his next batch of stuff. Are the 914 fronts the same in that you need to use compressed air to get the pistons out?

If you want to do them yourself read the tech articles at PMBPerformance.

http://www.pmbperformance.com/brakehowto.html

I get the pistons out using a block of wood in the slot between the halves where the rotor goes.
Blow one out carefully by using paint stir sticks as spacers removing them as you go.
Once the first one pops out, put it back in gently and shim with the sticks.
Then keep going until you blow the other out.
NEVER use the air method without restricting the piston motion mechanically.
Just a couple of PSI will launch one across the garage, and you might need 100 PSI to free a stubborn piston.

[john77]

Thanks Stu. I think I'm going to go the whole way and get them replated with zinc - my friend runs a shop so he said I can throw them in with his next batch of stuff. Are the 914 fronts the same in that you need to use compressed air to get the pistons out?

If you want to do them yourself read the tech articles at PMBPerformance.

http://www.pmbperformance.com/brakehowto.html

I get the pistons out using a block of wood in the slot between the halves where the rotor goes.
Blow one out carefully by using paint stir sticks as spacers removing them as you go.
Once the first one pops out, put it back in gently and shim with the sticks.
Then keep going until you blow the other out.
NEVER use the air method without restricting the piston motion mechanically.
Just a couple of PSI will launch one across the garage, and you might need 100 PSI to free a stubborn piston.

Thanks Stu, that's an awesome write up.