Brake pad stopped sliding...

Brake pad stopped sliding...

Author
Discussion

Andy 308GTB

Original Poster:

2,920 posts

220 months

Saturday 28th December 2019
quotequote all
Coming into Christmas I started to notice some grinding coming from the NSR brakes on my 2011 Mondeo.
I finally got around to taking a look and found that the inner pad was down to the rivets, the outer wasn't too bad. It was obvious that the inner pad wasn't sliding sweetly in the carriers - and therefore not releasing fully. It's created a few grooves in the disc.

I bought new pads (Yes, I know I should probably replace the disc too). But they weren't what you would call a loose fit in the carriers, especially the inner one. I filed the ears down on the new pads and they slide a bit better now.

Is this a common thing to have to do?, I've done a number of pad changes on a number of different cars and never seen this before.

borcy

2,584 posts

55 months

Saturday 28th December 2019
quotequote all
I had a similar issue, I just used a wire brush to clean up where the pads slide in and out. I guess it does happen as crude builds up.

Matt_E_Mulsion

1,690 posts

64 months

Saturday 28th December 2019
quotequote all
The pads should be the right size to fit a corrosion free caliper (and shims). If you've had to file the ends of the pads down to make them slide, I would suggest that you should have cleaned the caliper contact surfaces up more.

Andy 308GTB

Original Poster:

2,920 posts

220 months

Saturday 28th December 2019
quotequote all
I did wire brush the actual caliper, although it was pretty clean. I then polished up the metal carriers - so they were back to shiny metal. I also ensured that they were located correctly on the caliper. But the new pads still needed filing back to fit cleanly.



Edited by Andy 308GTB on Saturday 28th December 12:36

stevemcs

8,593 posts

92 months

Saturday 28th December 2019
quotequote all
Either the pad seized into the carrier, the sliders stuck (usually lack of maintenance) or the Caliper is starting to seize.

If the pads didn't fit, either ther caliper wasn't cleaned up enough or they are cheap pads - usually APEC.

borcy

2,584 posts

55 months

Saturday 28th December 2019
quotequote all
If you cleaned everything back to metal then it must be the pads. Have you used that brand before?

Matt_E_Mulsion

1,690 posts

64 months

Saturday 28th December 2019
quotequote all
Did you clean under the metal sliders? Often they can get that corroded under there you need to get a wire wheel on a die grinder on it to get 100% of the build up off there.

227bhp

10,203 posts

127 months

Saturday 28th December 2019
quotequote all
Andy 308GTB said:
I bought new pads (Yes, I know I should probably replace the disc too). But they weren't what you would call a loose fit in the carriers, especially the inner one. I filed the ears down on the new pads and they slide a bit better now.

Is this a common thing to have to do?
Yes with aftermarket parts.

LimSlip

800 posts

53 months

Saturday 28th December 2019
quotequote all
227bhp said:
Andy 308GTB said:
I bought new pads (Yes, I know I should probably replace the disc too). But they weren't what you would call a loose fit in the carriers, especially the inner one. I filed the ears down on the new pads and they slide a bit better now.

Is this a common thing to have to do?
Yes with aftermarket parts.
No its not, unless you are buying the absolute cheapest Chinese rubbish. 99.9% of the time if you have to file the pad down it;s because the carrier hasn't been cleaned up properly. They can grow a hard layer of rust that looks like steel after being wire brushed, but something like a carbide scraper will remove it.

Andy 308GTB

Original Poster:

2,920 posts

220 months

Saturday 28th December 2019
quotequote all
stevemcs said:
Either the pad seized into the carrier, the sliders stuck (usually lack of maintenance) or the Caliper is starting to seize.

If the pads didn't fit, either ther caliper wasn't cleaned up enough or they are cheap pads - usually APEC.
Bingo. Apec pads!
These were the described as the best choice out of the 2 brands that my local motor factors had in stock!

As an aside, I did pull the sliders and they were clean. I relubricated them & put them back.


Matt_E_Mulsion

1,690 posts

64 months

Saturday 28th December 2019
quotequote all
I really don't see the problem with Apec products, they've been around for years way before the cheap Chinese crap appeared on the scene. In fact in the last year my work van (Vito) has had all of its brakes done, front and rear, plus the handbrake shoes all of which were replaced with Apec products. It's what our local motor factors sell as their 'better' brand and they work just fine.

stevieturbo

17,229 posts

246 months

Wednesday 1st January 2020
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Apec are pretty crap to be fair.

And often it needs a good rough file or grinder type device to clean up corroded calipers to get pads to fit nicely.

Grinding at the pads should always be a last resort, Even Apec, although it seems like the quickest and easiest option at the time.

Andy 308GTB

Original Poster:

2,920 posts

220 months

Thursday 2nd January 2020
quotequote all
OP here... I may regret posting this but I feel bad for giving Apec products a bit of a kicking.

The following day, I decided to revisit my work as it didn't make sense.
The first thing I did was to to compare the Apec pads to the Brembo's that they had replaced. They were exactly the same size. This eliminated them from the problem. I then removed the brake pad clips and checked that there was no corrosion or crud built up on the caliper beneath them - none at all, all good.
I then put one side back together again and the pads sat noticeably better and felt more free. Puzzled, I then switched the pad clips around (i.e. top to bottom & vice versa) and the pads weren't as free. I then looked at the clips more carefully and it was obvious that they had been bent very slightly. On closer inspection of the caliper there is a ridge that pushes up on one side of the caliper that interferes with how the pad clip sits. At some stage in their life, the pad clips had been bent to accommodate this ridge. But they were now not interchangeable - and this was causing the problem.

I'm still not overly happy with this scenario but I am 99% convinced that this is the correct explanation.
I'm tempted to pull them apart again and check FFS biggrin