mc – Member

If new discs cure it, then it’s most likely a run out issue.

New discs have a nice continual thickness, but if they’re not running true, you get very slight rubbing at the high/low points. That very slight rubbing leads to uneven wearing/thickness, which is what causes the juddering. It doesn’t take much variation in disc thickness to cause a judder.

Ah OK, that makes a lot of sense- the way I was coming at it, it didn’t seem to add up but this is another route to the same result. Cheers!

maybe I use them a little harder than typical

No offence intended by my thoughts below but if you are warping the discs (as opposed to the other problems suggested above) then you need to consider for they are getting that hot that they’ll warp…

Do you use them forcefully a lot?
Do you carry a lot of weight?
Do you sometimes use them hard from high speeds regularly in short succession?

I’ve got a mk3 diesel wagon and it’s nowhere near that hard on its brakes.

My old 306 gti I could warp a set of new discs in about twenty minutes if I tried hard enough – on track.

The cause of the warping with that car was lots of sudden, hard decelerations without adequate cooling time between each use of the brakes. It has sweet fa to do with total miles driven.

If you are regularly hammering the car on twisty A roads or have a habit of being hard on and off the brakes and throttle at high motorway speeds (eg keep going down from 90-50 with the brake pedal on the carpet) then it’s conceivable you’ll be putting a lot of heat through the system but enough to warp three sets of discs would I guess take some serious abuse.

The brakes on the mark 3 are adequate but they’re not designed for really hard driving / repeated hard use.

Nah, nothing like that- like I say, just a little harder than might be average, but not frequent heavy use.

could it be something to do with the abs. probs not though if it stops with new disks.had the pulsing brake thing on a old n reg 306 sedan many years ago after the rear axle was changed cant for the life of me remember how i fixed it. sure it was abs related though.

Used to get this on a Pug 206. Was going through a new disc per main service! Okay the service interval is two years, except it isn’t as you do an interim service for oil change. Someone suggested this is part of the problem as the service intervals are done to keep the fleet market happy and they put harder pads in to keep it going, but these are warping the discs.

Don’t know if that’s true, but something was wrecking them. Don’t think it’s a heavy foot or my car washing regime (or lack of) as hadn’t had this with cars before the Pug and not since. Honda Civ now and not changed the discs in 7 years.

cp – Member
I notice it quite a bit in borrowed or hired automatics I’ve driven – I guess the tendency to hold on the brake pedal is even higher.

I’ve found this too with hired automatics. I’ve mainly only driven them in the US, but frequently they’ve had this. Especially the SUVs and 4x4s. Tends to be on ski trips and coming down from mountain elevations I think people are sat on the brakes a lot.

OK cool, thanks folks, pretty clear courses of action then. Ta!

Having had the last person to change the pads on my Mazda 6 not check the sliding pin seals were in place and having just had to get a blowtorch on the carrier holder to get the pins free again; I do sympathise Northwind. Replacement cariers (no pins, seals or calipers) are £240 each from Mazda!!!

I had original discs on a Zetec Mk3 at 75k.

Never warped them after braking late and sitting at the lights.

Had problems with the rear calipers sticky handbrake – never bought a Ford again.

stopped rather than standing on the brakes in drive?

No-one puts a car in park while waiting at the traffic lights. You’re not even meant to.

konabunny – Member
No-one puts a car in park while waiting at the traffic lights. You’re not even meant to.

Not what I was taught. At least not if stopped for any duration. Plus I learnt to drive in a very hilly and steep road area so handbrake hill starts at traffic lights were a necessity.

Anyway, on lighting – https://www.gov.uk/guidance/the-highway-code/general-rules-techniques-and-advice-for-all-drivers-and-riders-103-to-158

In stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again.

Note ‘should’. Advisory, not mandatory.

Plus I learnt to drive in a very hilly and steep road area so handbrake hill starts at traffic lights were a necessity.

Did you learn to drive in an automatic?

konabunny – Member
Did you learn to drive in an automatic?

Fair enough, no. Just realised previous comment was referring to automatics. Even then though, the highway code…

Actually, was driving an automatic in San Fran on those steep hills and I’d either sit on the foot brake or would use the equivalent of the handbrake (often a pedal) if a long wait in a queue.

Why are folk sitting with their foot on the brakes at junctions anyway? Don’t they teach proper driving these days?

Seemingly not, no. Last few folk I’ve heard of have been taught to use the foot brake rather than hand brake. No idea why as if you get rear ended then its instant loss of control and you are liable for anything you hit.

Seemingly not, no. Last few folk I’ve heard of have been taught to use the foot brake rather than hand brake. No idea why as if you get rear ended then its instant loss of control and you are liable for anything you hit.

If you get rear-ended the hand brake isn’t going to do much to stop you moving because it only acts on the rear wheels.

Try this, NW:

Take the wheels off and (carefully) give the surfaces of the brake disc a very thorough clean. Use wire wool and brake cleaner. You should (hopefully) feel the surface become smoother as you work, and the wire wool will grip less.

Give that a final clean with brake cleaner and a clean rag.

Now, offer a wheel up to the hub. Put the top wheel nut in, give it a few turns to hold it, then do the same with the rest. Try and make it no more than 4 full turns.

Then, going round in a star pattern, turn each nut twice. Keep going round until you feel the bolts bite the wheel itself. This bit won’t take long.

Finally, get your torque wrench, set it to the manufacturers torque settings for the nuts, and (still in a star pattern) start at the top, turn each but once, and keep going round until the torque clicks. Don’t be tempted to give it an extra turn for luck- just leave it at that.

Thats it. See if that helps.

chiefgrooveguru – Member
If you get rear-ended the hand brake isn’t going to do much to stop you moving because it only acts on the rear wheels.

The reasoning is that if you get rear-ended with your foot on the pedal your foot may slip releasing the brake and then you shunt the guy in front, and not only you are liable but it’s a bigger accident. Hand brake and car might move but will still be on the brake. Might still hit the car in front with enough force, but you aren’t liable.

I think the reasoning behind the advice about keeping footbrake applied at lights is so that brake lights are on and may alert the half asleep tosser who is about to run into you that you have brakes on and may be stopped.

(As an aside, if someone runs into that back of you with enough force to dislodge your foot from the brake, I think I would rather roll into the car in front and help dissipate the energy of the crash to protect my occupants)

I think the reasoning behind the advice about keeping footbrake applied at lights is so that brake lights are on and may alert the half asleep tosser who is about to run into you that you have brakes on and may be stopped.

It’s 15yrs now since MissT was taking driving lessons. When I questioned her on why she didn’t pull the handbrake on the answer given was that she had to be ready to move off when the lights changed without holding up other drivers 8O. Traffic lights around hear certainly seem to change faster than they used to, I’m more concerned about stopping distances when approaching lights and being rear ended if I stop on orange!!!!

If I suspect someone is approaching me at speed I will just give the brake pedal a couple of taps rather than sit with foot on pedal.

Because they put it in park when stopped rather than standing on the brakes in drive?

I’ve lived in the USA for nearly 3 years. 90% of friends drive automatics. 100% of them never use the foot brake and never put the car in park unless they are parking the car.
None of them have had warped discs, despite having heavy cars and it being hot a lot.

Someone in a car park reversed into me a couple of weeks back as I was waiting to pull onto the road. I had the handbrake on. If I’d had my foot on the brake instead, and my foot had come off due to the impact, then I could have been catapulted into the traffic on that road. That would be a road with trucks, buses and fast moving traffic.

I like driving threads 😀
But then remember I miss Surfmatt 😥

scotroutes – Member

Someone in a car park reversed into me a couple of weeks back as I was waiting to pull onto the road. I had the handbrake on. If I’d had my foot on the brake instead, and my foot had come off due to the impact, then I could have been catapulted into the traffic on that road. That would be a road with trucks, buses and fast moving traffic.

“…and that’s why Northwind’s discs keep warping”