Why are my discs warping?
Discussion
My workhorse is a 2006 C class avantgarde se with the sport pack (only gave the full Sunday name as its got the 330mm drilled discs as standard).
I've had the car 18 months, done roughly 40k in it and I've replaced the discs once and had a set skimmed too but they are now ready for doing again.
I bought Pagid discs and pads so thought the quality would be pretty good - I don't understand why they're constantly warping. I drive like I'm driving miss daisy, I do 100 miles a day all on the motorway and rarely use my brakes. I push it into N when at the lights but still the warping occurs.
Any ideas?
I've had the car 18 months, done roughly 40k in it and I've replaced the discs once and had a set skimmed too but they are now ready for doing again.
I bought Pagid discs and pads so thought the quality would be pretty good - I don't understand why they're constantly warping. I drive like I'm driving miss daisy, I do 100 miles a day all on the motorway and rarely use my brakes. I push it into N when at the lights but still the warping occurs.
Any ideas?
^ What he says. Discs don't warp, common misconception.
I was with the OP and fitted Pagid discs to my car and they were dreadful after just 100 miles. Pagid pads are great, but not had good experience with their discs. Amazingly in desperation I fitted a set of EBC discs and they were spot on
I was with the OP and fitted Pagid discs to my car and they were dreadful after just 100 miles. Pagid pads are great, but not had good experience with their discs. Amazingly in desperation I fitted a set of EBC discs and they were spot on
Mr2Mike said:
lanan said:
^ What he says. Discs don't warp, common misconception.
Discs certainly can and do warp, but the majority of brake judder problems are caused by other issues such as uneven pad transfer.I think I'll try a different type of disc, I chose pagid because they've always been good - might try textar
falkster said:
I do 100 miles a day all on the motorway and rarely use my brakes.
This is probably your cause.Driving without using the brakes generates DTV (disk thickness variation) which causes judder.
Check:
Wheel bearings for play
Hub faces for runout
Disks for runout (ideally when properly bolted up on the car)
Disks for DTV
You could also try giving the brakes a work out now and again to 'clean up' the DTV.
Edit:
You might find genuine Mercedes parts the best bet. They will have tested them for susceptibility to DTV generation and vibration during development. Pagid et al won't have.
Edited by blank on Wednesday 24th June 21:28
Are the calipers themselves clean and move freely?
How about the stub axle? if the surface the disc mounts to flat and corrosion free? Had a Porsche in that had a damaged mounting flange and when the wheel was bolted on it deformed the disc.
Also check the wheels are seated properly and if required the centralizing spacers are there.
Friend had very similar issues with a Merc people carrier. Turned out the wheels were the cause as they were moving slightly which caused judder under braking which felt like an out of true disc.
How about the stub axle? if the surface the disc mounts to flat and corrosion free? Had a Porsche in that had a damaged mounting flange and when the wheel was bolted on it deformed the disc.
Also check the wheels are seated properly and if required the centralizing spacers are there.
Friend had very similar issues with a Merc people carrier. Turned out the wheels were the cause as they were moving slightly which caused judder under braking which felt like an out of true disc.
blank said:
You could also try giving the brakes a work out now and again to 'clean up' the DTV.
Edit:You might find genuine Mercedes parts the best bet. They will have tested them for susceptibility to DTV generation and vibration during development. Pagid et al won't have.
Giving the brakes a good workout has cured rumble for me on a couple of cars!Edit:You might find genuine Mercedes parts the best bet. They will have tested them for susceptibility to DTV generation and vibration during development. Pagid et al won't have.
As for testing, vehicle manufacturers work with brake & friction material manufacturers when developing new vehicles, so the friction material manufacturer will be aware of any problems. Testing does, however, tend to concentrate on the higher end of the performance spectrum & is not done on vehicles which are a few years old . . . no point in testing the old model!
Mercedes OE pads are probably made by Pagid.
CrutyRammers said:
blank said:
This is probably your cause.
Driving without using the brakes generates DTV (disk thickness variation) which causes judder.
I may be being thick here, but how does not using the brakes cause the disks to change thickness Driving without using the brakes generates DTV (disk thickness variation) which causes judder.
It's certainly not cobblers. If it is then lots of car manufacturers are wasting huge amounts of money on testing.
blank said:
CrutyRammers said:
blank said:
This is probably your cause.
Driving without using the brakes generates DTV (disk thickness variation) which causes judder.
I may be being thick here, but how does not using the brakes cause the disks to change thickness Driving without using the brakes generates DTV (disk thickness variation) which causes judder.
It's certainly not cobblers. If it is then lots of car manufacturers are wasting huge amounts of money on testing.
fatjon said:
If the disk has runout then one cirumferential strip will be closer to the pad and wear in preference to the rest of the disk until such a time as the pads wear to take up the runout.
Read that back and see how daft it sounds. Pads can not possibly "take up" disc runout because the angle between the pads and disks is constantly changing as the disc turns. The pads will likely wear unevenly, as will the discs, but the wear can not compensate for the run outGassing Station | Suspension, Brakes & Tyres | Top of Page | What's New | My Stuff