Brake calliper failure

[NitroNJN]

Only 7 weeks ago my MX5 had a left hand passenger side front brake calliper failure
As a result I took it into my local garage where every brake disc and brake pad and offending calliper were changed.
The front right calliper was not changed though after I was assured by the garage that it was not unroadworthy
7 weeks later that unchanged calliper failed whilst I was on the M1, thankfully nothing bad happened- just scared me stoopid tho.
My quote from Mazda garage to replace f/r calliper and front discs & pads over £800 -
I spoke with the garage that carried out the work 7 weeks ago and they said ‘bad luck’ - what can I do ?

Shouldn’t brake callipers be changed fully like brake pads & discs are ? Shouldn’t that be made law ?

Edited by NitroNJN on Friday 24th March 08:48

[MustangGT]

Realistically, it is either an overhaul or replacement, at your cost. If the original place is cheaper than the dealer, which is likely, then take it there. It is unfortunate, but, it is what happens sometimes.

[E-bmw]

NitroNJN said:

Shouldn’t brake callipers be changed fully like brake pads & discs are ? Shouldn’t that be made law ?

So what would you do if you changed 3 tyres as 1 was OK & then the week later had a puncture, should changing all 4 tyres together be made law too?

What about just changing 3 spark plugs when 1 looked good, but then that one fails, shall we make changing 4 spark plugs the law too?

Is it the school holidays again?

[finlo]

Why would it need new discs again?

[NitroNJN]

So why is is ‘good practice’ to change both discs and pads but not callipers?
New discs because brake callipers seized on motorway destroyed brake pad and scored brake disc badly

[NitroNJN]

E-bmw said:

So what would you do if you changed 3 tyres as 1 was OK & then the week later had a puncture, should changing all 4 tyres together be made law too?

What about just changing 3 spark plugs when 1 looked good, but then that one fails, shall we make changing 4 spark plugs the law too?

Is it the school holidays again?

Think the ‘school holiday’ remark is a little unkind - it was a question not an instruction and you should learn to read properly before spewing an answer that bares no relation in answer to the question

[Scrump]

NitroNJN said:

So why is is ‘good practice’ to change both discs and pads but not callipers?
New discs because brake callipers seized on motorway destroyed brake pad and scored brake disc badly

Replace pads with new discs as the old pads will have been worn to fit the old discs so may not have a face which is flush with the new discs.
Replace discs and pads on both sides of the car at the same time in order to give equal brake force left and right. Replacing just one side may lead to uneven breaking (which is undesirable).

The failure of calipers is different, they don’t wear in the same way as discs and pads, and the force applied comes from the hydraulics, so as long as the pistons are clean and the seals are intact then the force applied by a new one should be the same as the force applied by an old one. Despite that I would normally change both calipers at the same time if I had any doubts.

[NitroNJN]

NitroNJN said:

Think the ‘school holiday’ remark is a little unkind - it was a question not an instruction and you should learn to read properly before spewing an answer that bares no relation in answer to the question

a spark plug failing is hardly a fair comparison- and in regards to tyres - yeah I understand - just replaced 2 new tyres 4 days after being fitted with replacements due to potholes - funny that I am entitled to compensation from the council on that matter though!

Edited by NitroNJN on Friday 24th March 09:40

[NitroNJN]

Scrump said:

Replace pads with new discs as the old pads will have been worn to fit the old discs so may not have a face which is flush with the new discs.
Replace discs and pads on both sides of the car at the same time in order to give equal brake force left and right. Replacing just one side may lead to uneven breaking (which is undesirable).

The failure of calipers is different, they don’t wear in the same way as discs and pads, and the force applied comes from the hydraulics, so as long as the pistons are clean and the seals are intact then the force applied by a new one should be the same as the force applied by an old one. Despite that I would normally change both calipers at the same time if I had any doubts.

Thank you Scrump- common sense and thoughtful too- unlike some responses. I worked in the Armed Forces servicing jets and it was and I’m sure still is ‘good practice’ to change 2 identical and life saving mechanical parts when both have been on a vehicle for the same period of time - if one fails the other is very likely to go soon after

[GreenV8S]

NitroNJN said:

Shouldn’t brake callipers be changed fully like brake pads & discs are ?

No. Calipers need repairing / replacing when they need repairing / replacing. When working on one it's good practice to assess the state of the others but that doesn't mean the others should be assumed bad.

NitroNJN said:

Shouldn’t that be made law ?

No. There is no law about replacing pads and discs as a set nor should there be. Siilarly it would be a bad idea to start introducing laws about what combination of things have to be serviced together. It would be a terrible way to solve a non problem.

The brakes and the rest of the car need to comply with the construction and use regulations and pass the mandated MOT tests. That's ample regulation.

[MustangGT]

finlo said:

Why would it need new discs again?

I would only change the calliper unless the disc had been damaged. In the event of disc damage I would replace the single one and put in new pads both sides.

Edited by MustangGT on Friday 24th March 10:55

[The Wookie]

As a brake engineer I would replace (or at least rebuild/reseal) to ensure their behaviour is matched, but unless the other is really far gone then it's not usually detectable and it's not common practice even in Motorsport.

To be honest though I'm fascinated to know why both calipers suddenly failed, it's incredibly unusual for them not to at least weep first or drag to the point of creating heat and a long pedal. Has the car been used on track?

[GreenV8S]

The Wookie said:

To be honest though I'm fascinated to know why both calipers suddenly failed,

It's possible that moving a piston outside its normal range of travel while replacing a pad in a worn caliper has damaged a seal.

[The Wookie]

GreenV8S said:

It's possible that moving a piston outside its normal range of travel while replacing a pad in a worn caliper has damaged a seal.

Yeah true, pads worn to the backplates on discs below minimum thickness.

You'd still need to pinch the seals both sides pushing the pistons back though, if it was just crap and corrosion on the pistons damaging the seal then again you'd just expect them to leak and give a long pedal.

[Jakg]

NitroNJN said:

So why is is ‘good practice’ to change both discs and pads but not callipers?
New discs because brake callipers seized on motorway destroyed brake pad and scored brake disc badly

Discs and pads are a consumable, calipers aren't.

[TwinKam]

Re: why not change calipers with discs & pads?Bottom line is.... the bottom line. Cost. Few would tolerate an extra couple of hundred pounds on their discs and pads bill, many sqinney about 'having to have' new discs as it is!
Different in the Armed Forces, it's not their money!

[stevieturbo]

NitroNJN said:

Only 7 weeks ago my MX5 had a left hand passenger side front brake calliper failure
As a result I took it into my local garage where every brake disc and brake pad and offending calliper were changed.
The front right calliper was not changed though after I was assured by the garage that it was not unroadworthy
7 weeks later that unchanged calliper failed whilst I was on the M1, thankfully nothing bad happened- just scared me stoopid tho.
My quote from Mazda garage to replace f/r calliper and front discs & pads over £800 -
I spoke with the garage that carried out the work 7 weeks ago and they said ‘bad luck’ - what can I do ?

Shouldn’t brake callipers be changed fully like brake pads & discs are ? Shouldn’t that be made law ?

Edited by NitroNJN on Friday 24th March 08:48

What do you mean they "failed" ?

Calipers don't randomly "fail"

[brman]

fwiw, I often replace only one caliper at a time on my cars. Normally it is the near side as they tend to corrode and stick more often than the offside. Not always though. Replacing just one side is perfectly fine as long as the other side is working properly.

Would it be better to replace in pairs? Maybe but most customers don't like paying for unneccesary work. Can imagine the grief they would get if they did both and the customer found out that they had just paid twice what they needed to?
Cars are most definitely not repaired to the same standards as aircraft. Thank god, because one would be able to afford it!

However, given they had replaced the disc/pad that side (so would have to have retracted the piston?) then it is perhaps a surprise it wasn't already obvious that the caliper was sticking. So a shame they did not spot and act on that.

That said, what are you hoping to achieve? I don't think you have any comeback on the garage. "It was ok when we did the work and you didn't ask us to do that" is a legitimate excuse and you cannot prove otherwise. You could be dissapointed in their thoroughness and perhaps not take your car there again. Or you could just chalk it up to experience and make your expectations a bit clearer on future jobs.

[Smint]

Japanese brakes need regular, preferably annual, attention...ie strip clean inspect and fully lube everything with the correct brake grease on reassembly, you don't need to remove the pistons when servicing but its wise to 'exercise' the pistons in their bores a few times to see what sort of resistance to be pushed back in is required.

I too wonder what you mean by failed, did the caliper start spewing brake fluid or did the piston seize in its bore causing the brake to overheat badly...if so refer to the first paragraph.

Replacing calipers individually is quite normal, but, you would pay special attention to servicing its opposite number to ensure its working as well as the new one t'other side.