Brake discs keep warping after seizure

[GSte]

My brakes seized up back in Dec 2010 and the RAC bloke unseized them by revving the engine and then letting the clutch out to give a sudden burst of power that unstuck the pads from the discs. Ever since then every set of discs I've had keeps warping. I've tried cheap generic ones and 2 sets of Brembos. The garage now wants to replace the wheel hubs (the disc that the wheel screws onto). Does this sound like a reasonable course of action? I've read elsewhere that this can be one thing to try but it just seems funny that this problem should only occur after the brakes had seized on. Does anyone know if something could have been bent during the RAC man's brake-freeing trick? Perhaps some part of the brake assembly or something else?

Just wanted to get some opinions on this before I spend another few hundred quid as this problem is getting to be fairly costly, and approaching the value of my car!

Car is a Peugeot 306 2001 1.8i XS.

Thanks for any help you can give.

 

[Burnerman]

Due to the high metal content of disc pads today, its common to have them seize on....but that really means that they just rust to the disc, and they'll come free when the car is moved - often with a bit of a clang.
This won't cause warped discs, but it may give a sort of high spot which will disappear after a few miles.
The pads will only lock in this way if the car is left outside and not moved for ages, or sometimes after its been washed and left for a while.
A warped disc will manifest itself by a slight bumping on the brake pedal as you slow down.
Hubs may be distorted if the old discs have been removed by using excessive hammer force to shift them from the hub...this is unusual, and once a hub is distorted it remains that way.
Just how often do your brakes seize on? I'm suspecting a collapsed flexible hose, or maybe a master cylinder fault, but first things first!
John

 

[GSte]

Thanks for the reply.

They just seized on the one time.... my power steering failed during a few weeks of heavy snow and I left my car sat on the drive for about a month until I could afford to have it repaired.

When the discs warp there is indeed a juddering sensation when I come to brake, accompanied by the steering wheel wobbling side-to-side. The problem also seems to throw the wheels out of balance/alignment, as the car becomes unstable at high speeds on the motorway too after a while.

I wonder if they used excessive force to remove the old rusty discs after they'd seized up and that that's why they think the hub(s) may be the problem.......?

 

[Burnerman]

There could be more than one issue here.....
You say the car becomes somewhat unstable at motorway speeds.....this is more likely due to worn shock absorbers or low tyre pressures (assuming the tyres themselves are ok, of course).
There should be no wheel wobble when you are not braking. If there is, its a wheel balance issue - if the wheel tugs and the pedal pulses when braking, thats a warped disc alright.
I'm wondering....is your garage replacing the pads as well as the discs?
Are they ensuring the hub is perfectly clean and rust free before the new discs are put on?
Hardly rocket science, any of my comments....but the Peugeot isn't especially prone to this more than any other vehicle.....indeed, vented discs are pretty hard to warp - assuming your car has them!
I'd like you to check that your brakes are fully releasing and not binding - after coasting to a halt, check each wheel is about the same temperature.
John

 

[GSte]

The garage is just replacing the discs but I think they tried the pads too originally.... I'll try and look back through the paperwork to check.

I assume that they are checking the hubs as it's in their own interest to do so as they have replaced the discs for free a few times, but I couldn't say for sure.

The discs are indeed vented, and the exposed parts of the hub that I can see in front of the discs look pretty rusty.

Apologies for the stupid question, but how do I check the wheel temperature after coasting to a halt?

 

[Burnerman]

Just with the palm of your hand against the wheel rim centre, mate - if one of the brakes is binding, that wheel will be hotter than the other.
Any part of the disc that isn't swept by the pad will be rusty after a while.
Its a pretty easy job to check for hub run out using a dial indicator - I would have hoped the garage would have done that.
Disc warping is usually due to a binding brake, causing excess heating.....the faulty side disc starts to discolour, usually to a bluish sheen.
It can be difficult to tell, without test gear, which side is actually warped.
I wonder if the garage are actually replacing the discs, or just turning them 180 degrees on the hub and then refitting them?
John

 

[GSte]

I'd hope that they're replacing them.... it's a chain garage so the guy I deal with said that it makes no odds to him to replace them as he doesn't own the company so isn't losing out.... But even if they aren't replacing them, they've certainly fitted two different sets of new ones at least (the generics and the Brembos) and both have warped.....

I'll check to see if the wheels are different temps and get back to you.

 

[AlanE]

There are disc AND drum brakes on the rear of these. Thoughts are that if the discs and pads have been replaced what about the callipers?

Think they are single cylinders with sliding pins. Are the callipers free to move as they should or are they sticking sometimes causing the disc to overheat?

Likewise does the handbrake free off correctly or are the drum brakes sticking and again overheating the discs?

 

[stuartturbo]

Wobble under braking could be track rods etc something I've had

 

[GSte]

There are disc AND drum brakes on the rear of these. Thoughts are that if the discs and pads have been replaced what about the callipers?

Think they are single cylinders with sliding pins. Are the callipers free to move as they should or are they sticking sometimes causing the disc to overheat?

Likewise does the handbrake free off correctly or are the drum brakes sticking and again overheating the discs?

Did wonder if some part of the calipers had rusted whilst it was sat on my drive for a month but the garage reckoned that they looked clean....

Think that the handbrake frees correctly..... it's the front discs that are warping though, doesn't the handbrake only work on the rear brakes?

 

[GSte]

Wobble under braking could be track rods etc something I've had

The actual steering rack or the track rod ends? Is there any way to tell if that's the problem without replacing them?

 

[GSte]

I'd like you to check that your brakes are fully releasing and not binding - after coasting to a halt, check each wheel is about the same temperature.
John

Just did this mate, both were equally cold....

 

[Burnerman]

Well, that just proves that the brakes are releasing as they should.....if that wasn't the case it would be an MOT failure anyway.
I sniff a bit of a rat here......I replace dozens of pairs of discs each year - I always fit new pads with them, always take the rust off the hub face, always apply a thin layer of coppaslip grease to the hub and they don't come back with a fault.
Your garage must be losing money big time, with all those replacements and not mentioning labour time.....yet they don't seem to be particularly concerned!
A couple of points....the handbrake only works on the back. If they are a disc/drum combination there's a small pair of brake shoes that hold the car on the handbrake...the disc pads only work on the footbrake in this system. We assume that these aren't warped but the symptoms could be the same!
Track rods and steering are easy to check - with the car body jacked up, the wheel is gripped at quarter to three and rocked to and fro.....wear on the track rod ends or track rods - even the steering rack shows up easily.
Personally I'd let someone else have a try - but there again it isn't me who is paying the bill.
John

 

[GSte]

Thanks for your advice and it all seems sound..... I could take it elsewhere but it's hard finding someone who'll do an honest job and at least this place always tends to take the cheaper option. Wouldn't go back to my local Peugeot dealer as they tried charging me £650 for work that didn't need doing (full exhaust system when car was 4 years-old due to heavy corrosion they reckoned.... got another garage to put it on the ramps and it looked fine and emissions were normal). The one advantage the current place has is that they're going to replace the discs for free again.... but maybe it would be worth going elsewhere just to finally get it sorted. Will see if there's anyone recommended on Honest John's site.