Singing Brake Pads

[RAC68]

Well, I guess it’s my turn to be confused by something that should be a very simple 20 minute job … I think.

I just put a set of new Moss Sintered Metallic Brake Pads in my BJ8 P1 and, for the first time in 50+years, I have Singing Brakes on my Healey. The anti-squeal shims are installed and there is a thin rubbery film attached to the rear or the pads that I presume is also for anti-squeal deadening. I have always used the sintered metallic pads on my Healey and, lucky or not, this is the first time I have had any problems with squeal.

I would appreciate any suggestions other then to go to another brake pad material as this simple task has become a real pain in the back.

Thanks,
Ray (64BJ8P1)

 

[Keoke]

Go to an anti squeal grease / lubricant or moss at one time had a nonmetallic anti squeal pad that worked very well.

OH: next time stay away from metallic pads unless you going racing.:highly_amused:

 

[HealeyRick]

You might try bedding the pads. It's free! https://www.stoptech.com/technical-...ions-and-procedures/stock-brake-system-bed-in

 

[RAC68]

Thanks Keoke/Rick,

I have used the same Sintered Metallic pads from Moss for the life of my Healey and this is the first time I have had any noise from a new installation. I guess I am just getting older and was wondering if I had done something wrong or there was something I now should have done. I will try bedding the brakes as I am using the original disks. As indicated, I had installed the Anti-Squeal shims but was wondering if that was correct since the pads seem to have a thin layer of some soft material on the back of the pad. No mention was made in the accompanying instructions that this material was for anti-squeal or if the shims should not be used.

Again,
Thanks for your replies,
Ray (64BJ8P1)

 

[HealeyRick]

Ray,

The coating on the back of the pad is there for anti-squeal. I've used CRC Disc Brake Quiet for the same purpose, which is a rubbery liquid you apply to the rear of the pad. I think I'd try bedding the pads first, because it's cheap and easy. If that doesn't work, maybe you could try removing the shims. Good luck.

 

[steveg]

I understand you can add a layer of duct tape to the back, as well.

 

[BoyRacer]

Disc brake squeal is caused by a very high pitched vibration between the caliper piston and the metal backing of the brake pads. It's odd that you would have squeal with both anti-squeal shims and the soft backing material. If it were me, I'd remove the shims and give the leading edge of the pads a slight chamfer where it meets the rotor. As for metallic pads, they are way too hard on rotors. I don't even use them on my race car.... I use carbon-kevlar... but they work best only after they get hot..

 

[RAC68]

Hi Rich,

Sintered Metallic brake pads have been installed on my Healey since new and the lower cost of available pads from Moss. My understanding was that these metallic pads were the standard and I chose them because I found them to be long wearing and provided quite adequate stopping power. I never thought the type of less-than-aggressive driving I do did not require pads made from exotic materials. As yet, I have not been able to address the issue but will try chamfering the pads as well as remove the anti-squeal shims. My last pads did not have the thin spongy material on the back of the pad metal so I will first test without the anti-squeal shims and, if that has little affect, will remove the spongy material and reinstall the anti-squeal shims.

I appreciate all the comments and suggestions as, in my over 50 years of ownership, this has been one issue I have not experienced.

Thanks everyone,

Ray (64BJ8P1)

 

[Bob_Spidell]

Don't the shims effectively duplicate the effect of chamfering (by tilting the pads a little)?

 

[RAC68]

Bob,

What would you recommend?

If I do not chamfer the pads and keep the shims installed, should I remove the thin spongy material on the back of the pads? I appreciate that the shims replicate chamfering of the pads if the spongy material is retained and shims eliminated, chamfering makes sense to me. However, I would rather keep the shims and have already experienced that keeping the spongy material with the shims results in my singing brakes. So, I am thinking of eliminating the material that came on the back of the pads and, if that also doesn't work, purchase anti-squeal pad dressing and try that.

Ray (64BJ8P1)

 

[John Turney]

I have the thin spongy material on the back of the pads and no shims and no squeal/singing.

 

[Keoke]

if the spongy material is retained and shims eliminated :
All that singing is going to go away'

 

[shortsguy1]

I called Moss technical support about this specific issue, and the last couple posts are dead on. As I understand it, those pads are intended to be used without any shims. This is how I installed them and they seem to be quiet.

For a totally different possibility, any chance one of those cotter pins that hold the pads is installed in a way that it touches the rotor or pad?

 

[Bob_Spidell]

Bob,

What would you recommend?
...

Dunno. I've always just used the shims with no sticky stuff, and never had a squeal in my BJ8. Squealing is due to some combination of the rotors, pads and how the pads are installed (or evil spirits). If shims only doesn't work, I'd try different pads (have had good results with Ferodo brand pads). Changing rotors is a big job, but if yours have serious grooves it might be time. If that doesn't work, try an exorcism.

 

[RAC68]

Hi All,

Well, I addressed the singing brake issue today with NO Success. I pulled the shims out and installed the pads with the thin foam and also lightly sanded the pads to start from scratch. I took the car out and went through a number of medium pressure stops with no squeal. Then it started and began to squeal on both front brakes each time the pads warmed on stopping.

I must admit I was expecting this to work. I am now considering taking the thin spongy material off the pads and try with the shims alone. If that doesn't works I plan to go back to the previous pads installation (3/4 warn) until I find a solution.

Why is it that the simple things can be the biggest pains in the (neck).

Thanks all,
Ray (64BJ8P1)

 

[BoyRacer]

Do not listen to Bob. The anti-squeal shims do not "replicate" chamfering the pads. They do not tilt the pads! Remove the shims, chamfer the leading edge of the pads and put them back in. If they still squeal then you will have to sell the car. Maybe Bob will buy it.

 

[RAC68]

Hi Rich,

First, I pulled the pads and refaced them again. I pulled the metal plates with spongy sealant securing them to t he back of the pads. I then took a slight bit off the leading edge of the pad and installed with the original shims. Tomorrow I will test and, will consider carrying an anchor if this doesn't work.

Thanks everyone but this 5 minute task has become quite a pain.

Ray (64BJ8P1)

 

[Keoke]

I will test and, will consider carrying an anchor if this doesn't work.

WAIT!!:Ray

For you do that and because this is a British car maybe you can try what the Brits do for these cases:

They coat the back of the pads with Coppa-Slip:

Available only over there or in Canada as it is a hazardous product here in USA .

 

[RAC68]

OK, I chamfered the pads and reinstalled my original shims (eliminated the shim with stuff between the pad and shim that came with the pads). Again, made a number of brake-in slowdowns without coming to a stop. The tune is a little different but it is still singing and, at times, loud. At this point I am going to put up with the squeal to see if it wares in. If after a week or so of driving, it doesn't go away, I will definitely start carrying the anchor.

Thanks for your patience and suggestions,
Ray(64BJ8P1)

 

[HealeyRick]

Ray,

I use these: https://www.summitracing.com/parts/hwk-hb169f-560/applications/make/austin-healey No noise at all and good stopping. Trying a new pad might be worth not putting up with those annoying squeals.

I also coated the back with CRC disc brake quiet.