New front discs at 34,000 miles? (55,000 km in new money)

[ChrisMiller]

My PHEV has just been in for its 5-year service (expensive enough on its own at just over £500), but I'm told I need a new pair of discs on the front (another £500+). Has anyone else experienced similar? My previous car (Honda Civic VTi) did 140,000 miles over 12 years and never needed new discs (occasional new brake blocks, obviously). I feel a strongly worded letter to Mitsubishi coming on as (of course) they're not covered under warranty ('wear and tear'). I'd expect brake components to last longer on a PHEV, where part of the braking is managed electrically.

 

[EssexBoy]

Well unless you drive like a hoolie (and I am pretty sure you don't) my guess is your dealer needs to generate a bit of work/revenue. Are the disks grooved? You can certainly run through two sets of pads before considering replacing disks - my front disks have done twice your mileage almost and they just passed the MOT okay. Get an opinion and or quote from a couple of independents as there's nothing special about our front disks/pads - I guarantee they will come in way under £500 ! Its likely you only need pads in reality.

 

[BCbackroader]

Are you in a very hilly area? Most of my driving is near level, with a few moderate hills each day, and at 129,000 km ( just over 80,000mi), I'm still good on the original pads, never mind the discs. I've been very pleased with the brake wear on this car.

 

[Nibbo]

I was a bit shocked that mine needed new pads and disks after just 24k miles, especially as I rarely use the brake.
I am sure previous cars have done 40-60k...

Anyway, further investigation showed that one of my calipers was binding a little. A new caliper was also required

Needless to say that since everything was replaced (by a local mechanic not £2,000 from Mitsy dealer) they are not binding anymore and the EV range has increased by about 20%.

I guess it was from lack of use that they seized so I tend to use them a bit more than I did before.

 

[ThudnBlundr]

If you drive sensibly, the car doesn't need to use the physical disks much for slowing except when the battery is full. It could be that lack of use caused corrosion to build-up, and that is not good for longevity.

 

[littlescrote]

If you drive sensibly, the car doesn't need to use the physical disks much for slowing except when the battery is full. It could be that lack of use caused corrosion to build-up, and that is not good for longevity.

The last few mph before coming to a stop also uses the physical brakes which is enough to wear off disc surface corrosion.

 

[AndyInOz]

My dealer complains because my disks and pads are still new, showing no wear.

Of course people who are more knowledgeable than me will explain that using the brakes rather than setting the regenerative levels via the paddles is exactly the same, and this can't happen.

:lol:

 

[ChrisMiller]

Thanks for your input everyone. It seems it was the brakes binding, for reasons unknown. I reported (a couple of months ago) squealing when travelling round bends, so that was probably it. At least the estimated mileage on the guessometer may improve.

 

[littlescrote]

The brakes binding is not for reasons unknown - it's because they're poor quality calipers and don't get exercised much.

What have you had done to prevent them binding again? New calipers under warranty?

 

[Nibbo]

What have you had done to prevent them binding again? New calipers under warranty?

New calipers for mine, NOT under warranty.

 

[littlescrote]

New calipers for mine, NOT under warranty.

Outrageous isn't it? You shouldn't need new calipers after that distance should you?

 

[Nibbo]

Well I thought I was hard done by...
A work colleague who bought his PHEV after a quick go in mine has just been told his need new pads, disks and calipers ALL ROUND!!! :evil:
His is a 2014 with £45k miles.

 

[ThudnBlundr]

Am I missing something? I've never replaced callipers on any car in normal service, even my '72 MG which I've owned since '85. In fact the only car I've owned that has had them replaced is the PHEV, and that was under warranty because of a design fault.

 

[jaapv]

I doubt whether your MG weighs 1900 kg... Never had to replace the callipers on my '63 TR4, which I own since 1993, either.

 

[ThudnBlundr]

But what wears out on a calliper? Why would it ever need replacing?

 

[user 3575]

It is mainly the piston seals, the piston can corrode especial if the piston boots deteriorate and allow in moister and debris, in the worst case scenario damage to the calliper body .

 

[jaapv]

The problem is that ABS systems must use Glycol-based brake fluid which can easily absorb moisture and thus cause corrosion. TheDOT5 Silicon-based fluids are better in that respect. However, they cannot be interchanged.

 

[littlescrote]

The PHEV caliper issues are generally neither of those 2.

For the fronts it is a bit piston corrosion, but also sliding pin corrosion. Both of these issues are nothing to do with fluid used etc, but are all about them not getting exercised much. The way that we tend to try and drive these things for best range means that we use regen braking and easing off the gas pedal rather than hard stops on the brake pedal which move the pistons significantly and frequently.

For the rears, it's a bit of the same of the fronts, but with the additional problem of the parking brake mechanism corroding as it doesn't always get used enough due to lack of piston movement and owners just putting it in P (or just switching off without applying the parking brake which defaults to P and locks the transmission negating the perceived need for the parking brake).

Both of these issues can be avoided by better quality materials, but as the calipers are platform shared with French cars, that doesn't happen due to cost constraints on the suppliers. So, as owners we have to take care of them ourselves by protection/lubrication (regular cleaning and servicing) and regular exercising of the calipers through hard braking.

Basically, they don't make 'em like they used to!

 

[BCbackroader]

My dealer here in Canada services the slider pins as part of every routine 8,000 km service. I now have 131,000 km on my '18, and the brake pads are not yet worn enough to replace.

 

[Nibbo]

My dealer here in Canada services the slider pins as part of every routine 8,000 km service. I now have 131,000 km on my '18, and the brake pads are not yet worn enough to replace.

Your mileage / wear ratio is what I would expect driving it the way I do with very little actual braking.
Perhaps MMC are aware of the issue but let it go on as a money spinner for the dealer network :twisted: