V50 Brakes : Do brake discs really warp?...I'm not so sure they do...

[DCN85]

The power or 'sportiness' of the car has little to do with the maximum temperatures you can achieve in the brake components.

It's simple physics...with a long and steep enough hill and a driver being silly enough to ride the brakes you could probably melt the brake discs if you really wanted to...Road car or otherwise. Although the brake fluid would start to boil somewhere in between...

This is why overheating and smoking brakes are common when drivers misuse them in mountainous areas.

[Volvo6]

The power or 'sportiness' of the car has little to do with the maximum temperatures you can achieve in the brake components.

Well if talking about 'spirited driving' or on a track, ie where one is likely to generate a large amount of heat in the brakes the faster the car the hotter the brakes will get...in general. Faster cars tend to have more powerful brakes, generating more friction and therefore more heat, the maximum temperature one could likely generate by a fast lap in a Volvo V50 will be less than say in a Ferrari.

It's simple physics...with a long and steep enough hill and a driver being silly enough to ride the brakes you could probably melt the brake discs if you really wanted to...Road car or otherwise. Although the brake fluid would start to boil somewhere in between...

I doubt you could actually melt them (the discs that is)! Obviously you will probably get serious fade but I think your brake fluid boiling would make the system lose effectiveness and ultimately reduce the friction on the discs before they had a chance to melt.

Interesting topic...

[DCN85]

Originally Posted by Volvo6

I doubt you could actually melt them (the discs that is)! Obviously you will probably get serious fade but I think your brake fluid boiling would make the system lose effectiveness and ultimately reduce the friction on the discs before they had a chance to melt.

Absolutely, I made the brake fluid comment in case someone would take the 'melt' literally. My point was simply that heat generation is not so limited as might be thought, regardless of the car. The topic was addressing whether sufficient temperature could be generated to warp the discs. What I'm saying is that with misuse of the brakes and a long windy downhill for example, overheating is more an expected outcome than a questionable one in my mind. Couple this with a subsequent stop and foot rested on the brakes...I can definitely see how warp would occur. Even road cars have their limits.

[Volvo6]

Even road cars have their limits.

Indeed...

Before this issue came up I'd never really given just using the footbrake a second thought, I guess it is a bad habit that a lot of drivers get into, especially since the 2.0D is very easy to get moving after coming to a stop, one just lifts the pressure off the brakes and the car is already moving without touching the gas. Even on a hill there is so much pull at idle that one doesn't actually need to use the handbrake, just lift and the car will move and then side one's foot across to the gas to keep the momentum going. Probably a habit picked up from driving a manual XC90 actually, I found the parking brake so awkward that I'd rarely use it while driving. I know better now...

[MikeLB]

Oh they do warp, but usually when they are worn down and considerably thinner than they used to be - Metal heats up and cools down, do this repeatedly over goodness knows how many tens of thousands of miles and the metal will start to change its inherent properties, leading to warping. Pretty fundamental science but it does happen.

I just changed my discs which were warped, the vibration became almost unbearable. What a difference. But granted, I never usually let discs get as worn as these ones were ...

[don kalmar union]

You most certainly can warp standard sized discs on most cars by repeated heavy breaking where the heat generated is not dissipating as it would in less arduous circumstances. If you are getting judder from warped brakes, then the simple remedy is not to drive in that way.... or, gets some air ducted into the centre of the discs, that will help.

It has also been mentioned earlier that uneven deposition of brake pad material can also cause judder, that is quite correct and can be avoided by proper bedding in of new pads on new discs, and not pulling the hand brake on when you have very hot discs, just leave the car in gear or wait for them to cool down, although, I have to say that you do have to be going some to heat up the rears as the front brakes do most of the work.

With many cars as they age the rears tend to get overlooked and do need a close look, a clean etc. from time to time.

Regards, Don.

[wimorrison]

I two cases, once on my v40 and then on my v70 I was told that I needed to replace the discs because they were warped and that I must be feeling a shake through the steering wheel. This is true, I'd feel a shake under braking but it was nothing to do with warped discs.

My issue was that a wheel had become dented on the inner rim and this imbalanced was noticed when braking.

I have told others to check the inside of their rims before changing discs and in all cases a dent on the rim has proved to be the culprit. Sometimes rebalancing will get rid of the imbalance, sometimes you need to have the wheel repaired but in all cases it was nothing to do with the diagnosed fault of warped brake discs.

[evil bill]

I wonder if we will see more instances of "warped discs" as more cars abandon the traditional handbrake for the electronic kind with auto hold?

My company car is a VW Passat 2.0 TDi and when I stop in traffic, my car is held by autohold which as far as I can tell holds the car on the front brakes only. If I am on a slight hill and manually activate the handbrake, you can feel the weight shift as it switches from auto hold to handbarake.

[nbuuifx]

I had new pads and discs fitted to a Celica good few years back. Within a few days I could feel a judder a went back.

They said I had warped the discs through too much heavy braking rather than bedding them in. (I had been down a local very steep hill). They were good enough to stick them on the lathe and skim them for me, and you could see they were out. Refitted and they were still perfect when I sold the car 2 years later.


I did have a caliper stick on, on a Ford Escort, that used to make the one disc glow orange at night - however even driving in rain it didn't warp. I got a 2nd hand caliper from the scrappies and continued on the same discs/pads.

[damienbuckley]

Greetings from Australia. Just came across this thread and thought I'd add my experience.

I have a 2008 2.4 Geartronic V50 R-design and today it's been returned with its third set (that's right 3) of brake discs. Last set was March. Since we've owned it they've also replaced drive shafts and replaced the front wheel hubs twice.

We've had the brake warping and wobble under acceleration issues described here and elsewhere in the forums since new and it appears there's no solution. It would also seem to be a problem common across the whole V50/S40/C30 platform.

Explanations provided:

Car could have been washed when engine / brakes still warm - Volvo's apparently can only be washed on a cold cycle…

Wheel nuts may not have been torqued down correctly - although serviced by dealer since new. Because we all carry torque wrenches in the boot…

We've today been told that he wobble under acceleration is 'a characteristic of the vehicle' from which I can only deduce that Volvo's are garbage? We've also been told that the brakes have been replaced 'as a courtesy' and as consumables are not warrantable items. It seems Volvo has a different concept of consumables than me. So I guess now we're stuck with this $50000 lemon.

Ridiculous excuses for extremely poor manufacturing. Time to own these issues Volvo while you still have a brand name worth a dime.