Brake pad ends sticking in calipers

[alan333]

Hi,

Having troubles with long brake pedal travel and poor handbrake feel on our 3.5 years old Mazda 3. It's done 23k miles, has been owned by us since new, and is serviced annually by Mazda.

On it's second service I asked Mazda to check the brakes and, of course, the answer was "it's fine sir".

A year later, and a bit worse (I don't drive it often), and with it's first MOT looming, I decided to have a look. There was plenty meat left on all pads but (some of) the pad ends were jammed in the calipers, causing uneven wear on the pads. The rear pads were only acting on about half the face of the discs on the inners, so new rear discs and pads were fitted. The front discs had a slight lip but the pads were working on the whole faces so it got new pads only. All cleaned up well and greased nicely with copper grease. Brakes felt perfect again.

Now, 6 months later, the same has happened again (but not as bad). Investigation shows the same - pads jamming in the calipers.

What can I do to stop it? More coppaslip, less coppaslip, different grease, etc etc?

Any input welcome

 

[Mottie]

Make sure all rust/corrosion is removed from the calliper slides and if they’re still sticking, take a fine file or some rough sandpaper to remove paint/metal from the end of the pads. Lubricate and refit.

 

[KenGMac]

alan333, good evening.

My son lives in Glasgow.
He has a Mazda 6 but not a new model
He used the main dealer their facility is near the Clyde down river from Finneston in the area near the Clyde tunnel.
By any chance was that the same dealer you used??
My son had severe issues with brakes, his rear disk surfaces were not being fully swept by the pads, the main dealer had fitted new pads previously, Mazda said all was well and a year later massive bill to replace disks, pads Et All

 

[Keithmac]

It can only be corrosion or incorrect size of pad or caliper.

I've had to grind 0.5mm off pads before (excessive paint application) to avoid binding.

If the calipers are aluminium bodied it's quite likely salt corrosion has caused the issues.

 

[alan333]

Make sure all rust/corrosion is removed from the calliper slides and if they’re still sticking, take a fine file or some rough sandpaper to remove paint/metal from the end of the pads. Lubricate and refit.

Thanks mate. Today I've done as you say, but I did the same 6 months ago (except I didn't remove the paint then). They weren't sticking, a fairly gentle squeeze with thumb and forefinger pushes the pads in to sandwich the disc. All the replacements were genuine Mazda btw. I've never had this problem on anything else over the years.

 

[alan333]

alan333, good evening.

My son lives in Glasgow.
He has a Mazda 6 but not a new model
He used the main dealer their facility is near the Clyde down river from Finneston in the area near the Clyde tunnel.
By any chance was that the same dealer you used??
My son had severe issues with brakes, his rear disk surfaces were not being fully swept by the pads, the main dealer had fitted new pads previously, Mazda said all was well and a year later massive bill to replace disks, pads Et All

No it wasn't Machargs/Arnold Clark in South Street, it was SDM in Falkirk, who are so incompetent they can't blow up tyres properly.

 

[Burnerman]

If I’m faced with this one, I remove the caliper holding bracket, prise out the anti squeal shims and file the rusty areas where the pads contact back to shiny metal.
I then coat all of the mating surfaces with ceramic brake grease and reassemble after wire brushing the pads and squeal shims.
A garage check usually looks at the pad thickness, and leaves it at that.
John

 

[alan333]

It can only be corrosion or incorrect size of pad or caliper.

I've had to grind 0.5mm off pads before (excessive paint application) to avoid binding.

If the calipers are aluminium bodied it's quite likely salt corrosion has caused the issues.

The pads, calipers and discs all genuine Mazda. The calipers are quite heavy so I wouldn't say they're aluminium, but they may well be. A wire brush took most of the crap off this time - last time it was ages with a file and emery cloth.

 

[alan333]

If I’m faced with this one, I remove the caliper holding bracket, prise out the anti squeal shims and file the rusty areas where the pads contact back to shiny metal.
I then coat all of the mating surfaces with ceramic brake grease and reassemble after wire brushing the pads and squeal shims.
A garage check usually looks at the pad thickness, and leaves it at that.
John

I've done exactly that - cleaned up, wire brushed and filed every touching component, except I used copper grease. Would ceramic grease be a better bet?

 

[Burnerman]

I find that the ceramic grease is a bit thicker, and being white its easier to see that the job has been done.....it also seems to hang around longer. I do the hubs and wheel inside faces at the same time.
Motor factors seem to supply the Granville product.
John.

 

[alan333]

Thanks for all the help everyone, I'll keep you posted in 6 months lol.

 

[Avocet]

When you say "anti-squeal shims", are these folded pieces of steel that push into the channels in the caliper that the tongues on each end of the pad slide in? If so, they're a perennial problem on the Nissan X-Trail. The calipers are made of cast iron (try them with a magnet). The shims are made of stainless steel and the pad backing plates are mild steel. You get electrolytic corrosion between the stainless and the cast iron (or mild steel). Stainless is vicious when in electrical contact with either of the others and will accelerate corrosion in the others. Every few months, the cast iron rusts and swells, "pinching" the stainless shims and making them tight on the pads. The only way I've found of keeping on top of the problem is pulling the shims out, and taking the rust out of the channels in the casting with a square file, then replacing them again. It's an appalling piece of design for damp climates! I also have to take a file to the tongues on the pad backing plates for the same reason. Copperslip (or anything with copper in it) just makes things worse because it conducts electricity better. Use the ceramic stuff if at all possible.

 

[alan333]

Thanks mate, ceramic grease it shall be on its next strip down

 

[DIYspanner]

Indeed, ceramic grease for bedding brake in.

A 500g tub is the most cost effective.

Copaslip dries out and causes sticking.