New brakes fitted but a knocking sound from the rear... - Page 2

d_a_n1979 · 7th September 2011, 08:56

Any more suggestions?

I've ordered some OEM MG pads from Rimmer Bro's so hopefully they'll be with me tomorrow and I'll be able to see if that cures the knocking

Could the caliper be at fault at all; if so what may have failed? Or could the rear disc be warped so the contact between the handbrake shoes is off slightly?

It's just strange that the noise is only coming from the rear n/s caliper and not the other side as well; the same pads have been fitted on both sides!

d_a_n1979 · 7th September 2011, 19:13

Anyone Have any other suggestions?

spyder · 7th September 2011, 19:38

How about the handbrake shoes. The retaining pin could have come loose, allowing the shoes to knock against the brake disk.

Craig

Typhoon190 · 7th September 2011, 20:29

Quote:

Originally Posted by spyder

How about the handbrake shoes. The retaining pin could have come loose, allowing the shoes to knock against the brake disk.

Craig

I've had that happen to me too, and boy does that make a bang when the pin catches!

d_a_n1979 · 8th September 2011, 19:31

Right... Still struggling with this

We changed the passenger side rear caliper today as we'd noticed that on the run from my home to the garage; the disc was still dirty and not warm at all whereas the drivers side rear disc and caliper were clean and very warm in deed (a spririted run down the bypass)!

Caliper had seized and lossened off but was starting to seize again so swapped them over (easier than faffing with a caliper rebuild kit)

Unfortunately the knocking in still there

The 'knocking' starts when I put on the brakes hard from a speed to around a dead stop; the knocking slows down as the car slows down

Could this posibly be a warped rear brake disc???

We're going to swap discs around on Saturday (R to L and L to R) and so if the knocking moves sides we known then it's the disc

Also; would I be able to get a refund or direct swap on this from Brakes Direct (seeing as it's les than a week old and with les than 50miles on it) or will I have to fork out for a new disc?

Thanks

Mike Noc · 8th September 2011, 20:02

In my experience you can feel a badly warped disc through the brake pedal - it will judder at road speed when you brake. When changing discs it is good practise to check for runout using a DTI or clock gauge.

Max runout on front and rear discs is 0.06mm for the 75/ZT.

Mike

damienp · 8th September 2011, 20:04

Put the old brakes back on and see what happens

VMax1000 · 8th September 2011, 23:29

Warped discs don't knock, they vibrate.

Front you'll feel in the steering, back you feel in your seat.

If it knocks during braking check the caliper fitting to the hub to start with.

d_a_n1979 · 9th September 2011, 08:00

Well it appears that the pads and disc arent making the best of contact as the rear passenger side disc still has surface rust on it even after a good drive out whereas the drivers side is nice and clean!

Could the pads be too shallow or the disc mishapen allowing this to happen?

spyder · 9th September 2011, 08:04

Are the slip plates all clean, with a nice layer of copper slip, on them. too much dirt and rust will cause them to jam and not release either. They need to move freely.
Don't rely on your abs at the moment.

7th September 2011, 19:38	#13
spyder This is my second home 75 CDT Auto Tourer , Rover 45 , Astra, Zaffira, Chev Captiva Join Date: Mar 2011 Location: Wilts Posts: 3,342 Thanks: 203 Thanked 436 Times in 360 Posts	How about the handbrake shoes. The retaining pin could have come loose, allowing the shoes to knock against the brake disk. Craig __________________ Chrome skull caps, EGR cleaned (original housing), Mondeo lower mounting, 12V outlets in the armrest and tourer boot, cat fixed, working FBH, Lidl plenum covers, DD with reverse camera.New speakesr/Tweeters with MDF rings. wood dash, Memory leather seats, wooden finished steering and handbrake, Xenon headlights.

9th September 2011, 08:04	#20
spyder This is my second home 75 CDT Auto Tourer , Rover 45 , Astra, Zaffira, Chev Captiva Join Date: Mar 2011 Location: Wilts Posts: 3,342 Thanks: 203 Thanked 436 Times in 360 Posts	Are the slip plates all clean, with a nice layer of copper slip, on them. too much dirt and rust will cause them to jam and not release either. They need to move freely. Don't rely on your abs at the moment. __________________ Chrome skull caps, EGR cleaned (original housing), Mondeo lower mounting, 12V outlets in the armrest and tourer boot, cat fixed, working FBH, Lidl plenum covers, DD with reverse camera.New speakesr/Tweeters with MDF rings. wood dash, Memory leather seats, wooden finished steering and handbrake, Xenon headlights.

7th September 2011, 08:56	#11
d_a_n1979 Banned 2004 MG ZT-T 190+ Join Date: Jan 2010 Location: Preston Posts: 957 Thanks: 97 Thanked 109 Times in 85 Posts	Any more suggestions? I've ordered some OEM MG pads from Rimmer Bro's so hopefully they'll be with me tomorrow and I'll be able to see if that cures the knocking Could the caliper be at fault at all; if so what may have failed? Or could the rear disc be warped so the contact between the handbrake shoes is off slightly? It's just strange that the noise is only coming from the rear n/s caliper and not the other side as well; the same pads have been fitted on both sides!

7th September 2011, 19:13	#12
d_a_n1979 Banned 2004 MG ZT-T 190+ Join Date: Jan 2010 Location: Preston Posts: 957 Thanks: 97 Thanked 109 Times in 85 Posts	Anyone Have any other suggestions?

8th September 2011, 19:31	#15
d_a_n1979 Banned 2004 MG ZT-T 190+ Join Date: Jan 2010 Location: Preston Posts: 957 Thanks: 97 Thanked 109 Times in 85 Posts	Right... Still struggling with this We changed the passenger side rear caliper today as we'd noticed that on the run from my home to the garage; the disc was still dirty and not warm at all whereas the drivers side rear disc and caliper were clean and very warm in deed (a spririted run down the bypass)! Caliper had seized and lossened off but was starting to seize again so swapped them over (easier than faffing with a caliper rebuild kit) Unfortunately the knocking in still there The 'knocking' starts when I put on the brakes hard from a speed to around a dead stop; the knocking slows down as the car slows down Could this posibly be a warped rear brake disc??? We're going to swap discs around on Saturday (R to L and L to R) and so if the knocking moves sides we known then it's the disc Also; would I be able to get a refund or direct swap on this from Brakes Direct (seeing as it's les than a week old and with les than 50miles on it) or will I have to fork out for a new disc? Thanks

8th September 2011, 20:02	#16
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: 11,567 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	In my experience you can feel a badly warped disc through the brake pedal - it will judder at road speed when you brake. When changing discs it is good practise to check for runout using a DTI or clock gauge. Max runout on front and rear discs is 0.06mm for the 75/ZT. Mike

8th September 2011, 20:04	#17
damienp This is my second home skoda estate Join Date: Feb 2009 Location: sheffield Posts: 3,474 Thanks: 15 Thanked 122 Times in 68 Posts	Put the old brakes back on and see what happens

8th September 2011, 23:29	#18
VMax1000 Passed Away MG ZT260 Join Date: May 2007 Location: Swindon Posts: 2,805 Thanks: 62 Thanked 325 Times in 249 Posts	Warped discs don't knock, they vibrate. Front you'll feel in the steering, back you feel in your seat. If it knocks during braking check the caliper fitting to the hub to start with.

9th September 2011, 08:00	#19
d_a_n1979 Banned 2004 MG ZT-T 190+ Join Date: Jan 2010 Location: Preston Posts: 957 Thanks: 97 Thanked 109 Times in 85 Posts	Well it appears that the pads and disc arent making the best of contact as the rear passenger side disc still has surface rust on it even after a good drive out whereas the drivers side is nice and clean! Could the pads be too shallow or the disc mishapen allowing this to happen?