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MGB Brake Squeal - Problem Solved

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Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
UPDATE

I consulted my MG specialist and he advised against using soft copper backing on the pads, since the this material will be pushed away quite fast. There seem to exist stainless steel anti-squeal backing plates, which are capable of withstanding the high pressure. But these he could not find anymore as a dealer in MG parts.

Moreover, these V8 pads from MINTEX have an asymmetrical division of the brake material, with one chamfered side being longer than the other . So this morning I juggled my pads around to get all brake pads as "trailing" with respect of the movement of the rotor surface passing by, not unlike the thinking behind the asymmetry of the brake linings on the rear drum brakes

I will be testing the new configuration this weekend, since humidity is much higher now, squeal may be non-existent in this weather anyway.
Furthermore I found some references to this product in some YouTube video's: LIQUI MOLY Brake Anti-Squeal Paste, it seems resistant to heat up to 1200C hot smiley

BTW, my specialist told me many modern cars also have almost unresolvable brake squeal problems. And indeed this week I was not the only squealing car in town..... grinning smiley



Edited 3 time(s). Last edit at 2017-05-19 10:38 AM by Donthuis.

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thomas.dahl Silver Member Tom Dahl
Bonn, NRW, Germany   DEU
I just replaced pretty much everything on my front suspension.. Disks, bearings, callipers, hubs, hoses, bushes, springs etc etc it all went swimmingly except for a huge amount of brake squeal. I did fit the self adhesive backing pads on my green stuff pads.. The squel could be heard from miles away..

I disassembled the pads and coated every thing except the faces and disks with liqui moli anti squeal grease.. After cleaning away any excess my squealing went away. Still not sure why this works so well.

I also have a little theory that if the brakes and not bled properly any residual air acts as a pressure reservoir affecting the squealing.. Maybe the pads don't retract sufficiently.

Anyway, anti-squel paste/grease works. At least for me.



Trying to fix up my dads old 1969 MGB. Lots to do. Lots to worry about. Lots of fun.

914efi Avatar
914efi Art McKinley
Westport, MA, USA   USA
1974 MG MGB
1975 Porsche 911 "Carrera"
My Audi had the pads glued with RTV to the pistons from the factory-at least the rears.



Edited 1 time(s). Last edit at 2017-05-19 11:43 AM by 914efi.

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Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
A general automotive parts store I sometimes use for oil filters and the like did not have the LIQUI MOLY in store, but advised using the modern ceramic past solution they offer instead.
It is a white label type sold under their own "Brega" brand and withstands temps up to 1400C, another 200C higher than the LIQUI MOLY hot smiley

For about €21,50 I now have enough paste to lubricate maybe the front brakes of a 50 MG's . Since the squealing did not stop with the new asymmetric direction of pads, this is just as well thumbs up
So once more the pads will have to come out, for a cautious application evading the pads faces. By now this disassembly becomes almost automatic grinning smiley

PS The guy told me the copper grease I still had, was seldomly used any more and even gives problems with brakes having an ABS system coupled in place.
Well brakepads and wheelnuts excepted I hardly ever used it myself these years (I do not like it on spark plugs either)



Edited 1 time(s). Last edit at 2017-05-20 10:39 AM by Donthuis.

glbishop Avatar
glbishop Gary Bishop
Spring Hill, FL, USA   USA
My left front brake will sometimes squeal a tiny bit, but only after it warms up, and only with light braking. Just the final 2 or 3 ft before coming to a slow gradual complete stop. Like pulling into a parking spot. With a slightly more aggressive stop, it doesn't squeal at all.

The car brakes strong, in a straight line, and the right front brake never squeals. Something is different but I've never bothered to study it.

Does slightly excessive wheel bearing play contribute to brake noise? Someone may know.

thomas.dahl Silver Member Tom Dahl
Bonn, NRW, Germany   DEU
Very good question! Can wheel bearing play affect squealing? Anyone know?

By the way... On LIQUI MOLY.. If 1200C is too low a working temperature I have to ask what do you have under your bonnet? :-)



Trying to fix up my dads old 1969 MGB. Lots to do. Lots to worry about. Lots of fun.



Edited 2 time(s). Last edit at 2017-05-20 01:39 PM by thomas.dahl.

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
I guess so, the rotor can move more in a sideways direction with the pads following this shifting in the caliper surrounding body (the caliper pistons are not the only squealing parts here).... eye rolling smiley
when I renewed my rotors I took extra care in proper shimming to the lowest acceptable endfloat on the bearing. "American" bearingsetting may be far less precise and generate more squealing thumbs down

In reply to # 3515441 by glbishop My left front brake will sometimes squeal a tiny bit, but only after it warms up, and only with light braking. Just the final 2 or 3 ft before coming to a slow gradual complete stop. Like pulling into a parking spot. With a slightly more aggressive stop, it doesn't squeal at all.

The car brakes strong, in a straight line, and the right front brake never squeals. Something is different but I've never bothered to study it.

Does slightly excessive wheel bearing play contribute to brake noise? Someone may know.

thomas.dahl Silver Member Tom Dahl
Bonn, NRW, Germany   DEU
What is going through my mind on this is that the squealing must be somewhere between 6,000 and 10,000 Hz. Something must be oscillating at this frequency and the squeal is happening between 1 and 50 'rps' of the wheel. Something is oscillating at too high a frequency to be caused by the wheel bearing.

I believe it is the pads rubbing and 'stick slipping' against the disks which can be damped out by using different pads, adding a damping medium like rubber or grease or affecting the rubbing action itself which would explain why the anti squeal sprays that you spray onto the disks work.

Many design considerations would also help such as bigger pads or the overall dimensions and design of the breaking system parts. Modern cars do not have the problem and indeed they have larger pads.

I keep remembering the noise a teacher can make rubbing chalk against a black board. Big chunks of chalk did not make the same noise and different manufacturers of chalk varied the effect. Very hard chalk would squeal more.

Just some thoughts...



Trying to fix up my dads old 1969 MGB. Lots to do. Lots to worry about. Lots of fun.

Bealey Avatar
Bealey Silver Member Joe & Barb Hahn
East Wenatchee, WA, USA   USA
1971 MG MGB "Bealey"
1974 MG MGB GT
As a point of interest, there are times that the density, or lack there of (I believe that cast iron is more dense than cast steel, and composite rotors are the worst of all), of the brake rotors will contribute to squealing problems but I would tend to try everything I could with the pads before I started swapping rotors.

All of the friction manufacturers will tell you that you are on the road to hell if you don't start with a new or newly, and properly machined rotor, all new hardware, etc.. As an experiment I replaced the pads on my CR-V last year with out touching the rotors and they worked ok for awhile and then started squealing. After applying various lotions and potions as well as the dampners that came with the pads I happened to look carefully at my old pads and realized that there were stainless steel shims on the back side. After quick clean up and some time installing them no more squeal. I can only guess that the shim must be able to "slip rather that stick-slip" so it doesn't set up a vibration.

My $0.02 and worth every penny. smiling smiley

Joe

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
That is what my MG specialist mentioned as solution, but could not find it anywhere for the MGB anymore......

Today the extremely high temp ceramic grease was applied by me, I had to be careful not to touch the rotor with the pencil I use for reaching the top and bottom rest positions. In an earlier post on this thread, somebody mentioned attaching teflon tape on these places, I must say grease is easier to work with. And the rear of the pads where they rest against the caliper pistons is always easy thumbs up

PS Mind you I had a squeal free system on the same V8 pads and new calipers, but with old rotors, one of which was grooved by wear and resulted in brakejudder at weak braking on >60mph
Strong braking made it go away. My new rotors are crossdrilled and grooved against glazing and then the squealing started after bedding in on the same type of MGB GT V8 pads confused smiley

In reply to # 3515756 by Bealey As a point of interest, there are times that the density, or lack there of (I believe that cast iron is more dense than cast steel, and composite rotors are the worst of all), of the brake rotors will contribute to squealing problems but I would tend to try everything I could with the pads before I started swapping rotors.

All of the friction manufacturers will tell you that you are on the road to hell if you don't start with a new or newly, and properly machined rotor, all new hardware, etc.. As an experiment I replaced the pads on my CR-V last year with out touching the rotors and they worked ok for awhile and then started squealing. After applying various lotions and potions as well as the dampners that came with the pads I happened to look carefully at my old pads and realized that there were stainless steel shims on the back side. After quick clean up and some time installing them no more squeal. I can only guess that the shim must be able to "slip rather that stick-slip" so it doesn't set up a vibration.

My $0.02 and worth every penny. smiling smiley

Joe



Edited 1 time(s). Last edit at 2017-05-21 06:43 AM by Donthuis.

tomkatb Avatar
tomkatb Larry Baygents
Dayton, Ohio, USA   USA
1963 MG MGB
I put modern pads on my B. Noisey!

I tried all the tricks. The goo on the back worked a while. The noise began again. Putting it on every other month worked.

At the local guru"s shop I asked what do you recommend. He said, the organic pads that were designed to work with the car!

Instant success. Cheapest pads. $14.95 as I remember.

I conclude that modern high tech pads are designed for heavier cars capable of much higher speeds. Brakes operate at much higher temperatures. In addition, in North America, virtually all new cars are automatics. Due to the transmission the the brakes are much hotter.

If you use your IR thermometer on the B and your daily driver you will see much different temperatures.

New organic pads are less than $20 and can be installed in twenty minutes. Faster than regooing them.

I believe due to,operating at the preferred temps they likely perform better than other pads. No way for me to,rest, however my car stops well. And quietly.



L.W.(Larry)Baygents
63B
77 Spit

glbishop Avatar
glbishop Gary Bishop
Spring Hill, FL, USA   USA
In reply to # 3515848 by tomkatb I put modern pads on my B. Noisey!

I tried all the tricks. ...

Instant success. Cheapest pads. $14.95 as I remember.

...
New organic pads are less than $20 and can be installed in twenty minutes. Faster than regooing them.

...

Yup.

I'm running $14.99 Duralast from autozone.
Just an occasional squeal from left front wheel as I wrote earlier in this thread.
I do use the red goo.

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
UPDATE number three: ceramic paste did not prevent squealing of my front brake pads after all sad smiley

Maybe I should've followed my own advice from many posts back: just change to different brands of pads until the squealing stops grinning smiley

PS I now have ceramic paste for >100 MG's is my guess, one needs a very small amount.....

UPDATE FOUR: tried bedding the new V8 pads in on the new rotors today, with repeated braking 70 mph to 30 mph on exits from the highway to prevent dangereous situations. eye popping smiley
This original Mintex recipe pertains to the wellknown semi-metallic 1144 productrange, also sold by MOSS BTW. Excellent braking, but once warmed up, pads squeal again like crazy sad smiley

Tuesday will see me mount standard pads from MOSS again and the battle to silence my B will continue hot smiley

PS One thing I noticed on my GBP240 originally numbered Mintex V8 set: the shape of these pad plates is asymmetrical, while their GBP202 standard ones are symmetrical
My older type standard ones I threw away were also symmetrical. I expect the same from the GBP202 MOSS shipment arriving at my place tomorrow. eye rolling smiley



Edited 3 time(s). Last edit at 2017-05-28 10:23 AM by Donthuis.

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
There are so many threads on brake pads, I will cover this one too: GBP202 "Gold" standard semi-metallic pads from MOSS do not squeak at all (so far) thumbs up
Full bedding in will take more time, so if this verdict changes I will post again. But after 50km with frequent braking, my confidence in MOSS (and China) is definitely on the rise

PS These pads got a discount price at MOSS these weeks and converted to US/EU currency cost me less than $16/€15 (VAT included, P&P excepted of course)
BTW, the pins were not in the package, but a set costs less than 1 UK Pound. If you are careful in not bending too far, you can re-use the old ones a number of times though..



Edited 4 time(s). Last edit at 2017-05-31 01:53 PM by Donthuis.

thomas.dahl Silver Member Tom Dahl
Bonn, NRW, Germany   DEU
Thanks Don.. I think this is rapidly becoming the general conclusion.. Get the basic pads from MOSS and ignore Green Stuff etc.

Update from my post above, I did manage to get my Green Stuff pads to be quiet for a short while, but after about 30 miles the squeaking came back with a vengeance. I too have now tried everything possible except changing the pads. It is all rather embarassing.

Is anyone using Green Stuff without squeaking?



Trying to fix up my dads old 1969 MGB. Lots to do. Lots to worry about. Lots of fun.

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