Can washing your car destroy your brake discs?

[Monkeylegend]

LotusOmega375D said:

I've had a chance to sleep on this now and think I have come up with a plausible explanation.

I was brought up driving a diet of 1960s / 1970s / early 1980s cars. Cars of this ere were infamous for rusting, particularly around the wheel arches. I therefore got into the habit of hosing around the wheel arches to remove any dirt and salt.

I have carried on with this procedure through to the present day. I think this is causing the disc scoring: i.e. some of the dirt and debris from the wheel arches is splashing back onto the reverse side of the discs. This would explain why only the inside of the discs is affected, since the exposed side gets directly rinsed clean with the hose pipe after I have cleaned the wheel rims. Meanwhile the back of the discs remain coated with bits of hidden crap, which eventually ends up scoring the discs when embedded by the action of the brake pads.

What also supports this idea is that I had a similar issue with a 62 plate all-disc brake Polo 3 years ago. I didn't give it much thought at the time, since I bought that car second-hand and it had covered a good deal more miles. I just assumed that I was a tad unlucky and bought 4 pattern discs and pads and got them changed locally.

So, if true, the moral of the story is don't hose out your wheel arches, unless you take the wheel off and cover the disc brake assembly. It also means that it was my actions which led to the heavy scoring on the inside of each disc, so I can't blame VW after all.

My current Merc was used by me as a Chauffeur vehicle until I retired. During that time it covered 280k miles, was washed at least four times a week by me using a hose, often more in winter, sometimes twice daily, and always cleaned inside the wheel arches.

Since I retired my mileage has dropped to about 6k miles a year and I finally had to replace the original rear discs a few weeks ago at 305k miles.

The fronts are now on their 3rd set of discs, including the originals, each set did about 130k miles, and their 4th set of pads, and for the first 9k miles it was a Hertz hire car.

Th moral of this story is that washing regularly and hosing behind the wheel arches has bugger all to do with rusting, warped discs in my experience, although I suppose all cars are different.

[Mr Walker Said]

This has also happened to me sadly. Mercedes C Class AMG Line. Washed and parked for two days, at first the brakes were seized on, but once I got it moving there was juddering through the pedal and the steering wheel. I too thought it would clear with use but it now needs new discs and pads all around. A very expensive mistake!!

Edited by Mr Walker Said on Monday 22 February 20:47

[Chris32345]

Mr Walker Said said:

This has also happened to me sadly. Mercedes C Class AMG Line. Washed and parked for two days, at first the brakes were seized on, but once I got it moving there was juddering through the pedal and the steering wheel. I too thought it would clear with use but it now needs new discs and pads all around. A very expensive mistake!!

Edited by Mr Walker Said on Monday 22 February 20:47

you will have had issues long before you washed it


Simply washing an leaving a car sat for a few days won't cause that


Or else nearly every car at a dealership would have knacked brakes

[Monkeylegend]

Mr Walker Said said:

This has also happened to me sadly. Mercedes C Class AMG Line. Washed and parked for two days, at first the brakes were seized on, but once I got it moving there was juddering through the pedal and the steering wheel. I too thought it would clear with use but it now needs new discs and pads all around. A very expensive mistake!!

Edited by Mr Walker Said on Monday 22 February 20:47

Well when you have spent a lot of money getting them replaced make sure you never ever drive in the rain again

And never wash your car again.

Out of interest who said they needed to be replaced?

[Evoluzione]

I wonder if anyone remembers the Audi (R8?) driver on here a while ago. He'd washed his car and put it back in the garage, IIRC sometime after he dragged it out where it got stuck in the gravel half in and half out of the garage.
There was then the usual forum 10 page response which went on for a week or so with him arsing around and failing to get his brakes freed off.
I don't think we ever found out what happened.....

Remember it's not only water which gets in there, but also whatever chemicals you use which may cause excessive corrosion.