Front brake disc warp

Jeff Turbo · 1st August 2019, 15:36

Hi Guys, got a problem with my ZTcdti. Ever since I bought it last year the front brake discs keep warping.
I've now had 3 sets of discs, put new hubs, pads, calipers and flexy pipes but they still warp after about 3 months. The calipers weren't binding but I changed them anyway
As I've changed all at the front I've run out of ideas, Can anyone throw some light on this problem as its getting expensive.
Thanks

RoverP480 · 1st August 2019, 15:45

Are you sure its warping or disc thickness variation . Not knowing you journeys but stopping with ones foot on the brake, especially with the discs hot can cause localised heat variation which can warp the disc.

Jeff Turbo · 1st August 2019, 16:06

Quote:

Originally Posted by RoverP480

Are you sure its warping or disc thickness variation . Not knowing you journeys but stopping with ones foot on the brake, especially with the discs hot can cause localised heat variation which can warp the disc.

Thanks but definitely warping, with new discs on its smooth when braking but after about 1000 miles I can feel a vibration through the steering wheel that gets worse the more miles I do. I drive about 30,000 miles a year

HarryM1BYT · 1st August 2019, 16:07

Quote:

Originally Posted by RoverP480

Are you sure its warping or disc thickness variation . Not knowing you journeys but stopping with ones foot on the brake, especially with the discs hot can cause localised heat variation which can warp the disc.

Correct, it can.

OP - What makes you thin your discs are warping, is it juddering a bit on braking?

A solution I found some years ago, which has worked several times for me...

On an empty bit of road, get it up to 70 and brake as hard as you can, without actually locking the wheels, but (important) do not come to a complete stop. Repeat twice more.

Idea is, that the stops with your brakes applied, causes differences in ability for the disc to cool and sets up stresses in the steel and it warps. Getting them good and hot relieves the stresses - the not stopping completely, prevents more stresses being set up.

Jeff Turbo · 1st August 2019, 16:16

Quote:

Originally Posted by HarryM1BYT

Correct, it can.

OP - What makes you thin your discs are warping, is it juddering a bit on braking?

A solution I found some years ago, which has worked several times for me...

On an empty bit of road, get it up to 70 and brake as hard as you can, without actually locking the wheels, but (important) do not come to a complete stop. Repeat twice more.

Idea is, that the stops with your brakes applied, causes differences in ability for the disc to cool and sets up stresses in the steel and it warps. Getting them good and hot relieves the stresses - the not stopping completely, prevents more stresses being set up.

After about 3000 miles when braking the steering shakes quite a bit on braking and when stopping it's not smooth, . I've never had a problem like this in 45 years of driving and it's a big of a pain

Mike Noc · 1st August 2019, 17:26

If you have a clock gauge worth checking the run out when you next change the discs.

I had a recurring fault and it turned out to be a bent hub, but I see you have already replaced those.

Mike Trident · 1st August 2019, 17:30

I had a similar issue with our VW UP, it turned out to be the pads. Fake mintex we think.

We went through 3 sets of discs before we found the problem

HarryM1BYT · 1st August 2019, 20:13

Quote:

Originally Posted by Jeff Turbo

After about 3000 miles when braking the steering shakes quite a bit on braking and when stopping it's not smooth, . I've never had a problem like this in 45 years of driving and it's a big of a pain

Well, try the fix I suggested, its quick and minimal effort. I didn't believe it could work, the first time I read about it, but work it certainly did. I was on the point of swapping the disks.

Just get them good and hot, then allow them to cool gently.

BigRuss · 1st August 2019, 20:20

What discs and pads have you been using?

Russ

The Rovering Member · 2nd August 2019, 02:19

Quote:

Originally Posted by HarryM1BYT

Well, try the fix I suggested, its quick and minimal effort. I didn't believe it could work, the first time I read about it, but work it certainly did. I was on the point of swapping the disks.

Just get them good and hot, then allow them to cool gently.

I just tried this as l have had what feels like warped discs on my car a few months after l replaced the front discs & pads. Three times on an empty A127 at 2am.
As far as l can tell it does seem to have made a difference. I'll see how it is on my way to work tomorrow.

Thanks for the suggestion, Harry.

1st August 2019, 15:36	#1
Jeff Turbo Loves to post MGZT cdti Join Date: Mar 2011 Location: Lincoln Posts: 473 Thanks: 5 Thanked 28 Times in 24 Posts	Front brake disc warp Hi Guys, got a problem with my ZTcdti. Ever since I bought it last year the front brake discs keep warping. I've now had 3 sets of discs, put new hubs, pads, calipers and flexy pipes but they still warp after about 3 months. The calipers weren't binding but I changed them anyway As I've changed all at the front I've run out of ideas, Can anyone throw some light on this problem as its getting expensive. Thanks __________________ 1958 White Ford Consul Convertible 1965 Gold Ford Zodiac Executive 1997 Blue Jaguar Xk8 Convertible 2004 Monogram Poseidon MGZT cdti 2004 Pearl Black MGZT 260 Last edited by Jeff Turbo; 1st August 2019 at 15:38..

1st August 2019, 17:30	#7
Mike Trident Posted a thing or two Rover 75 CDTi Saloon & Citroen C1 Join Date: Jun 2016 Location: Oakenshaw, Near Bradford Posts: 1,622 Thanks: 385 Thanked 552 Times in 328 Posts	I had a similar issue with our VW UP, it turned out to be the pads. Fake mintex we think. We went through 3 sets of discs before we found the problem __________________ Rover 75 2.0 CDTi (131Ps) Conn SE Saloon. (Manual) 160 Remap, cruise control, electric window blind, temp gauge, Real walnut / ZT interior, FBH with GSM control. BORN Tuesday, 5th October 2004 @ 12:35:52 This vehicle was the 104,679th 75 to run off the production line, out of 112,381 This vehicle was the 3,318th 75 CDT Connoisseur SE (135) to be made out of 4,744 This vehicle was the 12,440th 75 in Starlight Silver (code: MBB) to be made out of 14,280 Starlight Silver 75s

1st August 2019, 20:20	#9
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,405 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	What discs and pads have you been using? Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

1st August 2019, 15:45	#2
RoverP480 Gets stuck in None at the moment Join Date: Jan 2018 Location: Hereford Posts: 501 Thanks: 1 Thanked 165 Times in 146 Posts	Are you sure its warping or disc thickness variation . Not knowing you journeys but stopping with ones foot on the brake, especially with the discs hot can cause localised heat variation which can warp the disc.

1st August 2019, 17:26	#6
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,543 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	If you have a clock gauge worth checking the run out when you next change the discs. I had a recurring fault and it turned out to be a bent hub, but I see you have already replaced those.