TR2/3/3A TR3 front disk brake squeal cause?

[CraigLandrum]

First test drive in the newly restored TR3 and we are working out the
little kinks. Car runs fantastic. Only problem so far is that the front right
brake squeals when applied. All of the brakes (disks and drums are running with new shoes, pistons, everything. Haven't attacked the problem yet but suspect it might be as simple as a need to rebleed. Could some air in the line cause this? Sort of makes sense that if there were some air in the calipers that one piston might be actuating while the air in the other is being compressed, causing one side to apply more pressure than the other, perhaps resulting in a squeal. Is that logic sound?

I know this is trivial and I should simply rebleed and be done with it but wanted to know if anyone has experienced the same thing.

After we tweaked the timing the car runs like a scalded dog. I swear this thing is faster than any of my previous 6 cyl big Healeys.

Will post some pics of the finished car in the next few days.

 

[TR3driver]

Sort of makes sense that if there were some air in the calipers that one piston might be actuating while the air in the other is being compressed, causing one side to apply more pressure than the other, perhaps resulting in a squeal. Is that logic sound?

I don't think so. Except when the fluid is flowing, the pressure is the same throughout the system. So there might be a small differential in the first fraction of a second after you hit the pedal, but not long enough to notice.

That said, I don't know how to stop the squeal. The only thing that worked for me was some aftermarket anti-squeal shims of soft aluminum. Cut them with scissors and stick to the back of the pad where it hits the piston. But others have reported that it didn't help them.

 

[Don Elliott]

This question just appeared on the forum for the TR Register and what the TR4 owner found was that one rotor had been turned by some previous owner below the lower thickness limit. He changed the rotor and solved his problem. Check the thickness of your rotors.

It may be that your new pads need time to "bed in".

You could try swopping the pads around later if it still happens.

 

[Geo Hahn]

I had a squeal that I addressed by using semi-metallic pads (from Moss) that were guaranteed not to squeal and also used some of that blue goo that is supposed to prevent squeal. One or both fixed the problem (I know, not a very scientific approach).

 

[6TTR3A]

Same as Geo Hahn
I had the squeal after installing brake pads from NAPA. Tried the blue goo; some help...broke down & bought the Moss pads w/o the blue goo...improvement...redid the blue goo..SOLVED!! (That was 2000 mi. ago)
Frank

 

[bgbassplyr]

You might try pulling the pads and beveling the bottom (leading edge) of the pad with a file, belt sander, or grinding wheel so that you eliminate the sharp edge of pad vibrating against the rotor.

Jim

 

[rlandrum]

Just some clarification... These are brand new rotors and pads. I believe the pads are "mean green". Rotors were Moss, I believe.

 

[rlandrum]

Also, as I recall, my Father said it was pulling to one side, which suggests it more than just a noise problem.

 

[TR3driver]

Also, as I recall, my Father said it was pulling to one side, which suggests it more than just a noise problem.

Squealing brakes frequently do pull; I'd solve the noise first and then see if they still pull. They also wear out faster.

 

[Don Elliott]

For the first 43,000 miles from new, I swopped the inboard and outboard pads on the front brakes on my 1958 TR3A several times because the pads were not all wearing the same. I was swopping them on the same side, then onto the other side. The inboard pads were wearing a lot faster that the outboard pads which is logical. Maybe I had a heavy foot back then. At 43,000 miles I put in new pads and they did not show this problem at all. And this second set of front rotor pads lasted till the mileage was up to 174,000 miles.

 

[trfourtune]

Bleed them again if they pull. Then apply the blue goo to the back of the padS and let it set up a little. Install pads and very lightly apply the brakes-just enough to put pressure on the pads. Let sit overnight.
Now go out and drive the car and make progressive stops from increasing speed and pressure (say 15 stops-last significant one from high speed to 10mph-at no time should you stop and sit with the brakes appied) then go home and park. Let sit for 2 hrs then go for a drive and see how they are.
Squeel is usually from vibration of the back of the pads against the caliper pistons.
R

 

[CraigLandrum]

Thanks for all the suggestions - will look at them this Saturday when we hope to have some sunshine here in VA.