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Hoping someone can help out here. My mate at work bought a brand new x trail in 2006. He has done 16,000 miles only. He took it to the nissan dealer he bought it from after he suspected something was a miss. They told him the front discs are warped. Like him i can't believe this on such a new car. He has been in touch with nissan but i don't think he has got any satisfaction of them as yet. Can anyone pass comment here please, have they experienced this. I have looked on technical side can't see anything. Hoping X trailman comes on line and puts an angle on this. Thanks in anticipation. By the way it's the diesal X trail.
Edited by Pugugly on 19/07/2009 at 21:50
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Discs can become distorted for a number of reasons. For example, if machining cuts are too deep, stresses can be built into the discs during the manufacturing process. When the brakes are used the stresses become relieved and the discs distort. This occurred on early production of Hillman Hunter derivatives. The manufacturer refined their machining process and the problem disappeared.
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They are very cheap to buy just replace them.
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.......... just replace them.
It's advisable to fit new pads at the same time as new discs.
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its hardly new is it?
people say to me it had a new exhaust and battery and you look at the scrappy receipt and its something like 3 years ago they were exchanged
consumables its the new in word/
don"t leave foot on brake after youv"e cut all the traffic up to shoot off at the next motorway exit (not that you would ,im speaking hypothetically, Nissan X-Trail drivers dont do such silly things)
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I veha an 07 Xtrail - service twice but I felt the brakes were not 100%.
Took it to my local Indie and asked them to look into matters - they stripped the brakes back and front and found the pistons had seized on 1 side on all 4.
Problem is that 2 @ 12 and 24 mth services are little more than oil changes at a main dealer.
The Indie always strips the brakes when he services my other (older) car. A 30 mins of labour is cheaper than seized pistons and warped disks.
Part of the OP's problem is low mileage and lack of use of brakes - that is what my Indie said was my problem.
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OP says warped rather than sticking FB
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OP says warped rather than sticking FB
The sticking pistons can cause build of heat and therefore warping!
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Why would holding the car on the foot brake be detrimental it just the same as putting the handbrake on unless its the model with rear drums.
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Sticking piston means pad does not lose contact with the disk whilst driving - friction ( and higher fuel consumption!) and build up of heat on disk / pad leads to warping!
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If you brake from speed, the front disks will get very hot (they do most of the braking)
If you then hold the brakes on, once you have stopped, the heat can't dissipate as the pads are touching, but the rest of the disk cools - this imbalance in temperatures causes the warping.
MVP
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Exactly the same as putting the handbrake on its a old wifes tale it makes no difference.
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Whatever the reason for the warp then even with a full dealer service history you're not likely, given the age, to get a penny from Nissan. Best to just get them changed and move on.
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Andy... brakes have to dissipate a phenomenal amount of energy. You must have seen ceramic brakes on fire after hard stops; well, the same energy still has to go into the steel discs.
The handbrake ususally works on the rear wheels, and often on a separate drum brake. You only need the tiniest amount of warping to give an awful vibration through the wheel when braking gently at high speed.
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On my CRV the dealer told me that if I had complained in the first 12 months they would have replaced them under warranty as I complained at 20 months I was told I would have to pay.
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Andy... brakes have to dissipate a phenomenal amount of energy.
I have to agree with Andy. There are thousands if not millions of motorists who leave their foot on the brakes without suffering warped discs. It's an old wives tale. Even with your foot off the brakes the pads are very close to (if not lightly touching) the discs.
The handbrake usually works on the rear wheels and often on a separate drum brake.
Zafira, Vectra-C, & Astra-H, to name but a few use the rear discs for both the foot and hand brake.
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>>a few use the rear discs for both the foot and hand brake.
They're all awful designs!, done properly, a small drum is used inside the disc. This is how Vauxhall used to do it, as fitted to Senators (B), Carltons (Omega A), and the faster mkII Astras and mkIII Cavaliers.
Disc warping is quite unusual. It's more common to see either variation in disc thickness, or transfer of pad material which manifests itself as a thickness variation.
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It's this intense heat that causes rotors to warp. With conventional and even metallic brake pads, the brake pads and rotor rub against each other; the pads make the rotor hotter, while the rotor makes the pads hotter. This keeps going back and forth between the pads and the rotors until they get intensely hot. Then, when the wheel finally stops turning, you have a piping hot pad sitting in one place of the rotor. What happens then is the rest of the rotor cools off a lot quicker than the spot where the hot pads are sitting. This is where the warpage comes from.
for rotor read disc-------
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>>It's this intense heat that causes ...
That's the generally held view, but, as ever, I'm not sure.
So often it turns out that the generally held view is not correct that in terms of motoring failures which are popularly ascribed to one cause or another without evidence, I've become "rather difficult to convince". [there's a shorter word, but I would doubtlessly spell it badly!]
Edited by Number_Cruncher on 20/07/2009 at 22:19
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>>It's this intense heat that causes ... That's the generally held view but as ever I'm not sure.
I'm not sure its the heat that warps them either. Plenty of people take road cars on track days and push the brakes to the limits without warping the disks.
I've often wondered if over or uneven tightening of wheel bolts could be a cause. Or even corrosion on the wheel causing uneven pressure to be applied. Just an idea mind, I'll never be able to prove it to NC's satisfaction and peer review :)
The truth is probably that there are many reasons why disks warp.
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Rubbish,why did they never warp on my stroker Camaro which often ran at over 200mph and 80k kilometers were still like new.They warp because they are not seated properly, going on short journeys, getting wet and then dry as in off roading,poor quality or getting worn they don,t warp being used as they should.
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If warped discs are his only problems on a XTrail then he should consider himself very lucky !!
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Thank you everyone for your input. Some interesting replies. I think modern manufacturing techniques should now produce a near perfect disc. interesting about the peripherals pads shoes not serviced correctly could be a cause. Seems general concensus is change pay up and shut up. X trail man must be on hol. Thanks ill let me mate know what you all said.
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just to add,in the old days of real discs and real man pads made of asbestos we never really had warped discs till they were so thin they looked like a 78rpm record,these days you look at modern pads and im sure they have old bits of nails and lino in them
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....... same energy still has to go into the steel discs.
I thought they were generally cast iron.
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like drain pipes
nice
:-)
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Have a read of this:
tinyurl.com/b58pz
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So to quote
"...never leave your foot on the brake pedal after you have used the brakes hard. "
The discs don't warp, it's material from the pads sticking to parts of the disk after getting very hot that causes the juddering.
MVP
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seems like it but it still stands that the old wives tale is based on fact though
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So to quote "...never leave your foot on the brake pedal after you have used the brakes hard. " The discs don't warp it's material from the pads sticking to parts of the disk after getting very hot that causes the juddering. MVP
Maybe.........................How does the pad material transfer to the disk though, by holding the car on the foot brake after repeated heavy use?
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From the article it sounds like the pad melts onto the disk
MVP
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From the article it sounds like the pad melts onto the disk MVP
When the disk / pad is cold and stationary or after heavy braking and the driver holding the car on the foot brake?
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Dox
Why don't you just read the article Andy P has posted?
MVP
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>> Steel >> I stand corrected.
On second thoughts .........
Extract from Andy P's link.
"MYTH # 2 - RACING BRAKE DISCS ARE MADE FROM STEEL
To digress for a moment "steel discs" are a misnomer frequently used by people who should know better. This group includes TV commentators and drivers being interviewed. Except for some motorcycles and karts, all ferrous discs are made from cast iron - an excellent material for the job. While steel has a higher tensile strength, cast iron is many times stronger than disc brake requirements. Its thermal transfer characteristics are significantly better than those of steel so that the heat generated at the interface between pad and disc is efficiently carried through the friction faces to the interior surface of the disc and into the vanes from where the heat is dissipated into the air stream. Cast iron is more dimensionally stable at elevated temperature than steel and is a better heat sink - so let us hear no more talk of "steel" brake discs."
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why do they rust then
plus my car isnt a racing car
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Iron + water + oxygen = iron oxide (rust)
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I always thought they used ceramic on racing cars thats whats on F1,2,3 cars.
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Carbon fibre discs and pads on F1 AFAIK.
Ceramic an option on road going Ferraris and that ilk.
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Certainly not cast iron or steel.
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