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Hi all,

 

Just returned from a 600 mile trip to Wales, fitted new standard pads to my 4a on the return trip brakes started squealing badly.

 

2 questions why do they squeal?

 

I have some anti squeal shims should I fit them, how do they work?

 

 

sorry that's 3 questions

 

thanks for any good advice Lee

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Clue is in the name and they do work to stop squealing, make sure you fit them the right way round, they have an arrow to help, good slap round of copperslip helps too. Also correct cleaning off of the discs before fitting and proper bedding in makes a lot of difference too.

Stuart.

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Hi Lee,

they squeal because they vibrate.

This is caused by either the leading or trailing edge of the pad touches the disc on an otherwise flat pad.

This bounces off and causes the other end of the pad to touch. It repeats itself until all the pad is in contact.

The shim 'cocks' the pad so that one edge is in firm contact and then all the pad is in contact.

 

There are PTFE shims that simply absorb the vibrations.

 

I think part of the problem is if the retaining pins are tight in their holes. Make them a sloppy fit.

Make sure that the pad is also slightly 'sloppy' with in the caliper.

 

Roger

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Clue is in the name and they do work to stop squealing, make sure you fit them the right way round, they have an arrow to help, good slap round of copperslip helps too. Also correct cleaning off of the discs before fitting and proper bedding in makes a lot of difference too.

Stuart.

I know exactly what you mean Stuart re arrows. However, if you buy the shims from Moss or Rimmers (as I have done this week) they are perfectly flat 16 thou thick plates with absolutely no markings on them whatsoever. Can't really see how this works to reduce squeal, although I do always use copperslip as well.

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Lee,

Roger is spot on (as always).

Make sure the blocks can slide free over the pins in the caliper.

Replace corroded pins that do not have a smooth surface.

Sometimes is little filing (but just a little) is required to make the holes for the pins large enough.

The guides in the calipers for the blocks should be smooth too, no edges or corrosion.

Waldi

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Often just the make of pads

Agree & possibly the material. I had to change to a different grade of Mintex because of squealing despite different shims & chamfering of the pads. Instantly ok once I made the change!

Cheers.

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Hi Monty/Alan,

the actual squealing is not caused by the braking material on the pads as such but by the metal part of the pad vibrating on the caliper.

The anti-squeal shim places the pad onto the disc at an angle and should sort the problem (dream on)

 

There are some special anti-squeal lubricants that are wiped on the pins and sides of the metal pad backing to stop the squealing (Hmm)

 

It is all a mystery

 

Roger

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Hi Roger,

Some squeal may be caused as you say but the pad friction material can and as in my case does cause it as well.

Alan.

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Hi Monty/Alan,

the actual squealing is not caused by the braking material on the pads as such but by the metal part of the pad vibrating on the caliper.

The anti-squeal shim places the pad onto the disc at an angle and should sort the problem (dream on)

 

There are some special anti-squeal lubricants that are wiped on the pins and sides of the metal pad backing to stop the squealing (Hmm)

 

It is all a mystery

 

Roger

Yes Roger I tried different lubricants & shims but the only cure for me was to revert to a fast road pad from Mntex which immediately cured the squeal. A mystery indeed! I think the grade of pad I first tried was too 'racy' & needed more heat than I could give it on the pot holed roads of UK!

Cheers.

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I've just fitted new discs, calipers and Mintex 1144 material pads. Car stops very well, but when gently braking the squeal is horrendous. I fitted anti-squeal shims and new pins, all suitably lubed with copper grease. The pads are sliding easily in the calipers and on the pins. No tightness anywhere. I must have done similar jobs dozens of times and never had this problem ever. The Mintex website states that squeal is just caused by vibration between the pad and the disc, which explains why it doesn't happen on braking hard, but this is so enbarrassing and I found it awkward to hide under the dash when people stare! One thing does puzzle me though. How can the totally flat, full pad size shims as supplied by Moss and Rimmer possibly work. As I understand it the function of a shim is to slightly tilt the pad, thereby giving it a slight lead-in to the disc. I'm tempted to buy some of the self adhesive pads that seem to be popular these days. I was hoping that the squeal might go away when the pads bed in but so far this hasn't happened. I've read all the posts and there's nothing mentioned that I haven't tried. Any thoughts folks. Mike.

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I've just fitted new discs, calipers and Mintex 1144 material pads. Car stops very well, but when gently braking the squeal is horrendous. I fitted anti-squeal shims and new pins, all suitably lubed with copper grease. The pads are sliding easily in the calipers and on the pins. No tightness anywhere. I must have done similar jobs dozens of times and never had this problem ever. The Mintex website states that squeal is just caused by vibration between the pad and the disc, which explains why it doesn't happen on braking hard, but this is so enbarrassing and I found it awkward to hide under the dash when people stare! One thing does puzzle me though. How can the totally flat, full pad size shims as supplied by Moss and Rimmer possibly work. As I understand it the function of a shim is to slightly tilt the pad, thereby giving it a slight lead-in to the disc. I'm tempted to buy some of the self adhesive pads that seem to be popular these days. I was hoping that the squeal might go away when the pads bed in but so far this hasn't happened. I've read all the posts and there's nothing mentioned that I haven't tried. Any thoughts folks. Mike.

I had the same head turning what is that dreadful screeching sound coming from the old car - reaction from pedestrians when I changed to mintex 1144. The braking was superb but in the end Id rather put up with less efficient braking with cheaper Boggo pads than notify the whole town where I live that old car was on the road. Nothing I could do stopped the noise so I switched to different pads.

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Hi Mke,

do try the stick on PTFE pad backing. They work on my brakes

 

It is interesting to see the Moss shims. Instead of imparting a leading or trailing edge they impart a lower edge tilt.

Can't possibly work 11

 

 

Roger

Edited by RogerH
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I've just fitted new discs, calipers and Mintex 1144 material pads. Car stops very well, but when gently braking the squeal is horrendous. I fitted anti-squeal shims and new pins, all suitably lubed with copper grease. The pads are sliding easily in the calipers and on the pins. No tightness anywhere. I must have done similar jobs dozens of times and never had this problem ever. The Mintex website states that squeal is just caused by vibration between the pad and the disc, which explains why it doesn't happen on braking hard, but this is so enbarrassing and I found it awkward to hide under the dash when people stare! One thing does puzzle me though. How can the totally flat, full pad size shims as supplied by Moss and Rimmer possibly work. As I understand it the function of a shim is to slightly tilt the pad, thereby giving it a slight lead-in to the disc. I'm tempted to buy some of the self adhesive pads that seem to be popular these days. I was hoping that the squeal might go away when the pads bed in but so far this hasn't happened. I've read all the posts and there's nothing mentioned that I haven't tried. Any thoughts folks. Mike.

r

 

I had exactly the same problem with 1144 pads Mike. Tried the adhesive pads but no cure. Dumped the 1144 & went to 1155 material. Instantly cured. I think the 1144's just do not get hot enough in normal driving. I have heard that Hawk pads from Cambridge Motorsport are a good uprated pad.

Cheers,

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Well I tried to find some adhesive anti-squeal pads, but failed....none in Bristol it seems. "used to stock them" "they all come with the pads mate" etc etc. There's some on e-bay but couldn't wait. So, off down to Moss and bought some of their Classic Gold "Ceramic". These have the shims already bonded to the pads. Fitted and bedded them in. Perfect. Good stopping power and absolutely no squeal. As for fade, I've no idea. Last time I experienced that was 50 years ago. Borrowed my Dad's Mini (he raced, sprinted and hill-climbed it) for a trip to Germany. Chasing a big Merc down a mountain I only just managed to stop at the bottom. Foot hard on the pedal and handbrake on. Mind you the car was still on drum brakes although with what were then called racing linings. Perhaps I'll find out next year, planning a tour round the French and Italian Alps. In the meantime I intend getting some adhesive shims to fit the 1144 pads just to satisfy my curiosity. Anyway, happy bunny for now. TTFN Mike.

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Had 1144 squeal problems on both a TR8 and Vitesse, Steel Shims sorted it on the TR8, a piece a duct tape on the back of the pads sorted it on the Vitesse.

 

Did it matter that the duct tape slowly disintegrated? No. From my experience pads are more susceptible to squeal when new, when they stop squealing, they stop squealing.

 

Alan

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Yes Roger I tried different lubricants & shims but the only cure for me was to revert to a fast road pad from Mntex which immediately cured the squeal. A mystery indeed! I think the grade of pad I first tried was too 'racy' & needed more heat than I could give it on the pot holed roads of UK!

Cheers.

Nope...wrong way around.

 

Mintex Racing Compound Brake Pads

The Mintex brand is the most famous when it comes to motorsport. Through intense Research and Development Mintex materials cater not only for Original Equipment and Aftermarket needs but at the other extreme for competition purposes. It is from motorsport that the latest family of Mintex materials have been developed. Material compounds available are M1144 for fast road, track day and light race use, M1155 for use when a higher brake temperature is used commonly in Rallying and M1166 commonly for endurance racing cars where temperatures are sustained for long periods of time.

 

Often the disc has been "burnished" by the old pad and fitting new pads without aggressive bedding in merely transfers the polished surface from disc to new pad material. Try breaking the disc surface polish with an 80 grit or less number emery to help provide an initial "bite" to bed the pads in ( make sure you use breathing mask protection).

 

Mick Richards

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Nope...wrong way around.

 

Material compounds available are M1144 for fast road, track day and light race use,

Often the disc has been "burnished" by the old pad and fitting new pads without aggressive bedding in merely transfers the polished surface from disc to new pad material. Try breaking the disc surface polish with an 80 grit or less number emery to help provide an initial "bite" to bed the pads in ( make sure you use breathing mask protection).

 

 

 

+1 Mick's bedding in suggestion.

 

Also as an aside, and not that I take any notice, but all the M1144 boxes I have state "Not for use on the Public Highway" Not I suspect because they aren't a brilliant pad from cold (they are) but I suspect the compound which is very dusty, may transgress a few HS rules?

 

Alan

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In the past I have had several sets of M1144 brake pads and always supplied with self adhesive anti-squeal pads to go on the back. However, I just purchased a new set for my TR250, different packaging and no anti-squeal shims or pads supplied.

 

These were all bought in the UK as Mintex don't seem to supply in North America.

 

Cheers

Graeme

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Mum was a great mechanic. "David your brakes are squealing, they need oiling". "Good idea mum, will oil them when I get home"

 

I think she had some more good ideas for getting rid of me as well.

 

Dave

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