warped disks, can they be saved ?

[Diagro]

Your best bet imo, is to replace pass and disks. Whilst your at it but some maintenance kits for the calipers. Clean the piston, and replace the pins.

 

[Vince]

I seriously doubt you've genuinely warped that many discs. More than likely you've not warped any, it's actually very rare.

In all likelihood it's a result of what Lashout describes but it may also be worth getting the fittings checked thoroughly, make sure it's not just a bolt or something routinely working loose.

Also agree, I would bet it's an issue with the guide pin. I have this exact same issue on my little clio and pulled the caliper apart and sure enough there was a big dirty groove in the pin where a small stone or something got in, or a previous mechanic has done. I have a new caliper which I keep meaning to get around to putting on. But yea the judder under breaking is real in that little car.

 

[jpaul]

Yeah you're gonna need to explain how you came to this conclusion.

obvious no ? the thickness/thermal conductivity/expansion across the machined disk will vary , so, if it really warped once, will be doubly prone.

 

[Firestar_3x]

I love a good warped brake disc "story".

From Alcon:

https://alconkits.com/technical-info/brake-tech/56-the-myth-of-warped-brake-discs

Have you ever heard someone say they had warped brake discs? Typically someone had the discs resurfaced to cure the problem and after a relatively short time the roughness or vibration came back.

In almost every case, this problem is not caused by a warped discs, but that the brake pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation or run-out due to hot spotting that occurred at elevated temperatures.

Shocker.

 

[dvinell]

One of the worst things you can do to a disc is to come to a full stop from high speed then sit hard on the brakes.
The disc cools unevenly, bits of pad end up fused to the disc, it’s not great.
But to actually warp a disc? I’m not sure how that would happen unless there was a huge amount of heat due to something being stuck.

 

[MassiveJim]

So I've ordered a set of pins, I will ask the garage to give the calipers a good ole' cleanup. Including disk mating surfaces and the back of the alloys. Maybe can clean the disks themselves up with some cleaner.
Take it for a run do some heavy braking and then we'll see where we are at.

Then I'll have a think about replacing £180 quids worth of disks and pads.

 

[tl45]

If you're replacing the slider pins is it also worth replacing the rubber boots the pins fit in to?

Could be some wear there that's contributing, Ford parts diagrams show them as individual items so should be obtainable and not too costly on top of the cost of the new pins.

 

[eviled]

Cementite deposition is the issue usually

Warping from high temps or sitting on the brakes at lights is an old wives tale

Go to a private strip of road and continually brake from high speed to 10mph and that might work, it did on mine

 

[area51]

One of the worst things you can do to a disc is to come to a full stop from high speed then sit hard on the brakes.
The disc cools unevenly, bits of pad end up fused to the disc, it’s not great.
But to actually warp a disc? I’m not sure how that would happen unless there was a huge amount of heat due to something being stuck.

Hi was just about to say the same thing! driving autos is the worst for that mind most bod just hit the brakes then hold the pedal down till need to move again instead of feather the pedal off as slow down so don't get the jerk as car stops one of the worst is dam bus drivers everyone jolts up and down the bus.
Brake hard the start to release the pedal as slowing don't need maximum pressure anymore.

 

[Scania]

I bought a 2nd hand set of calipers/disks/pads off ebay

IMO this was your biggest mistake, second hand brake components, just no.

As for warped discs, it’s largely unheard of tbh in anything other than hearsay, truck discs (which have a very much harder life than cars) don’t warp, even after getting red hot (you can see the glow through the wheels at night!)

As said, it’s the pads that tend to be the issue, assuming the callipers are ok which in your case OP it’s hard to prove they are ok given they were used to start with, if you do replace the discs & pads, get new (emphasis on new) callipers also.

I’m not sure why this is all bold?

 

[MassiveJim]

little update

given the advice in this thread, I decided to do a couple of hard stops this morning, on the 3rd or 4th hard stop I had huge brake fade and left a little cloud of smoke behind me.

After that the vibration was massively reduced, there was definitely some vibration still there although i cannot be 100% certain that isn't a wheel balancing issue.

That being said it does appear that this could be down to a caliper issue, when the car goes in to the garage I will have him service the calipers and hopefully that should resolve the issue.

IMO this was your biggest mistake, second hand brake components, just no.

As for warped discs, it’s largely unheard of tbh in anything other than hearsay, truck discs (which have a very much harder life than cars) don’t warp, even after getting red hot (you can see the glow through the wheels at night!)

As said, it’s the pads that tend to be the issue, assuming the callipers are ok which in your case OP it’s hard to prove they are ok given they were used to start with, if you do replace the discs & pads, get new (emphasis on new) callipers also.

I’m not sure why this is all bold?

The car is a 16 year old Mondeo ST220, and the standard brakes have a reputation for being poor so I upgraded the brakes to calipers/disks from a Focus ST. This is why I bought 2nd hand.

 

[Scania]

The car is a 16 year old Mondeo ST220, and the standard brakes have a reputation for being poor so I upgraded the brakes to calipers/disks from a Focus ST. This is why I bought 2nd hand.

By all means do the upgrade, I understand why you’d want to, but second hand is often just a false economy, as your finding out given your in all likelihood going to end up with new anyway.

Do a few more hard stops,hopefully for you it may well get better assuming all is ok.

 

[vanpeebles]

I have no issue with second hand calipers as long as they were a good make/OEM rather than a knock off clone. If they looked too cruddy or rusty, then they would need the seals doing etc. 2nd hand pads and discs are false economy, unless you are totally skint

 

[InvaderGIR]

I have no issue with second hand calipers as long as they were a good make/OEM rather than a knock off clone. If they looked too cruddy or rusty, then they would need the seals doing etc. 2nd hand pads and discs are false economy, unless you are totally skint

Indeed.

I bought a bigger brake set up for my car a couple of years ago, second hand...they don't make the brakes anymore so it was that or spending about 5x as much on a 'big brake kit'. I didn't get discs or pads, just calipers and spindles but the calipers weren't in the best of condition, being mechanically minded though it was less of an issue for me than it may be for some people. One caliper had clearly sat with some old brake fluid in and it'd oxidised and utterly grim sludge came out when I was cleaning it, it was also sticky so cleaning it was a good idea. Externally they both looked the same and looked fine but because they were second hand I made sure to go over them and ensure they weren't completely knackered.

 

[MassiveJim]

I have no issue with second hand calipers as long as they were a good make/OEM rather than a knock off clone. If they looked too cruddy or rusty, then they would need the seals doing etc. 2nd hand pads and discs are false economy, unless you are totally skint

Its a common mod on the ST220 as the standard brakes are the same ones used on all engine sizes for that car.

As for the ones I bought, they still had the original red paint on them and did not look appear to be in bad condition, that said a cursory glance to my almost untrained mechanical eye does not mean that the internals are in good shape.

As I said I will get them serviced with new pins and see how I get on, by the looks of things I have probably wasted £280 on 2 sets of disks and a set of pads up to now thinking the disks were warped when they were not.

 

[vanpeebles]

Its a common mod on the ST220 as the standard brakes are the same ones used on all engine sizes for that car.

As for the ones I bought, they still had the original red paint on them and did not look appear to be in bad condition, that said a cursory glance to my almost untrained mechanical eye does not mean that the internals are in good shape.

As I said I will get them serviced with new pins and see how I get on, by the looks of things I have probably wasted £280 on 2 sets of disks and a set of pads up to now thinking the disks were warped when they were not.

I had a mk3 2.2 tdci, and the brakes on that were probably the same, nearly caught me out a few times, and I'm not all that fast on the roads really.

 

[Phemo]

I had a similar problem on my old 320d. It was fine for ages then all of a sudden I started getting brake judder, most noticeable at 50mph and over. I changed discs and pads and it was ok for another few months but then it started again. I changed discs and pads again and then it came back a couple of months later. At this point I simply took the caliper and pads off, pushed the piston back in and then put it all back together and it was again ok for a few months so that was clearly caliper related.

 

[Howard]

Brake disks are more likely to shatter before they actually warp. It's just pad deposits. I've managed to cure it very occasionally with a few hard stops as Lashout said, but it's more often than not very persistent!