4.3 Front Brake Skim

[Sussex_Paul]

Just out of interest, has anyone else had to have their from brake discs skimmed since buying a 4.3?

Mine started to produce a fluttering sensation through the brake peddle and the steering wheel upon light braking applications a few weeks back.

It's only done 6000 miles and yet the dealers said that the front brakes needed skimming.

They promptly booked the car in and did what was needed, but the service manager told me that if the problem persisits, then they'd fit new front discs and pads for me, under warranty.

The car feels fine now, and I'm hoping it was just a one off, but I'm interested to know of any similar experiences.

[bothwell_buyer]

Just out of interest, has anyone else had to have their from brake discs skimmed since buying a 4.3?

Mine started to produce a fluttering sensation through the brake peddle and the steering wheel upon light braking applications a few weeks back.

It's only done 6000 miles and yet the dealers said that the front brakes needed skimming.

They promptly booked the car in and did what was needed, but the service manager told me that if the problem persisits, then they'd fit new front discs and pads for me, under warranty.

The car feels fine now, and I'm hoping it was just a one off, but I'm interested to know of any similar experiences.

I don't know much about the discs on your model. However my '94 RAV has had 3 sets of Toyo discs; + I think they were skimmed twice; and then I went onto EBS discs which got wrecked when the dust shield disintegrated; and I switched to rotordiscs which are a funny shape, worked well, but distorted within 2k miles due to excessive heat build up and a mis-behaving caliper. In looking at the discs, they are slimmer (about 18mm?) than most I think and so maybe prone to heat distortion - I admit to driving my RAV hard. In asking garages around here, its becoming less common to have discs skimmed. The minimum thickness of the disc is apparently stamped on the inside of the disc (so the manual says).

If it was me, I'd be taking the car back to get new discs... whilst they pay. The last time I checked, I think the discs were coming close to £200 a pair.

[druand]

Never heard of discs being skimmed on nearly new car still under MANUFACTURERS WARRANTY. I would be wary of having to pay at a later date when fault could be classed as "fair wear and tear due to time and mileage".

Enjoy your new toyota.

[Sussex_Paul]

Never heard of discs being skimmed on nearly new car still under MANUFACTURERS WARRANTY. I would be wary of having to pay at a later date when fault could be classed as "fair wear and tear due to time and mileage".

Enjoy your new toyota.

Thanks for your constructive comment.

Hope you're enjoying your new but rather ugly HONDA CRV

[anchorman]

I worked in Research and Development for a major manufacturer of brake pads for many years.

There are 2 types of run out that will cause judder. The first is pure run out where the disc becomes distorted like a buckled wheel. That is normally caused by thermal shock. An example might be if you left the motorway on a slip road and left it until the last moment before putting a large amount of energy (heat) into the brake at the last minute. It is possible to wharp a disc by unevenly tightening wheel nuts.

The other source of judder is called DTV (disc thickness variation). This can be the other end of the scale where constantly low duty operation results in very little wear of the disc. However some wear is inevitable but tends to vary as the disc rotates through 90 degree segments and is partly due to the casting grain which runs across the disc. In one plane it is with the grain and the other it is across it so it wears thick/thin. The normal process of braking is usually enough to true the disc.

The disc is normal grey cast iron with a specified titanium content. It is possible for them to have a fault but usually has very little bearing on the matter. You will hear all kinds of nonsense about using this brand of disc or the other but invariably the only thing that differentiates one from the other is how well they have been machined.

The pads on your RAV are absolutely first class. We spent millions of pounds trying to develop pads to compete with the !Removed! but they have us licked. Their processes are too consistent for us to match without huge investment.

I suppose we have to wait while we all get some mileage up to know if there is a general problem but hopefully it is a one off.

Cheers

[Kev76]

Another cause of discs warping/distorting is if you cool them too quick!

If you went through a deep puddle or washed your wheels after a long run of heavy braking this would cause the disc to warp and judder under braking!

Let your brakes cool before washing the car!!

[Sussex_Paul]

The dealers told us that the two front discs had 'minor surface deviations', which was why they said that skimming would resolve the problem, but they have told me that if the brakes leave me in any doubt concerning their effectiveness at all, then they will change them under warranty.

I get the impression that it may just have been a minor manufacturing issue in the disc itself, rather than an problem that has been caused by driving the car.

I don't know if it is possible that imperfections may occur within the disc at manufacture and only become apparent as the disc wears down to the level of the imperfection??

They are working perfectly at present, so I'm hoping it's a one off as there are probably plenty of owners with more than the 6900 miles on their cars that are currently on mine, who have not responded with any similar problems.

Thanks for your feedback in any case

[druand]

I may now own a CRV but still enjoy this site. New car is all I expected, lots of thought into detail, i.e. tailgate,rear parcel shelf,rear tonneau,arm rests and many small improvements from Rav-2.

Performance and economy very good. 3500 mls over 3 months = 42.3 mpg

T 180 is a superb unit but could not justify extra 5-6k just to have cruise control ( an essential item due to hip problems) I will have to go to an automatic next time (not too soon i hope) and will have a complete rethink for an auto with diesel and cruise or suffer a petrol Rav or Crv.

Enjoy your motoring.

Drew

[anchorman]

Another cause of discs warping/distorting is if you cool them too quick!

If you went through a deep puddle or washed your wheels after a long run of heavy braking this would cause the disc to warp and judder under braking!

Let your brakes cool before washing the car!!

Correct Kev. That's another example of thermal shock but the rapid change is in the opposite direction.

Regards