Rear parking brake Granturismo - Occasional scratching sound

azapa

Member
Messages
1,300
OK guys, car on jacks on driveway so quick answers appreciated.

Occasional scratch grumble from rear left of car, seems to be from the small parking brake drum inside the hub. I hardly ever use the parking brake, but it does cycle when I park.

It almost sounds like there is a small stone kicking around in there that catches once in a while.

Ideas? How hard is it to get in there and remove the drum to see the pads etc? Thanks
 

CatmanV2

Member
Messages
48,547
OK guys, car on jacks on driveway so quick answers appreciated.

Occasional scratch grumble from rear left of car, seems to be from the small parking brake drum inside the hub. I hardly every use the parking brake, but it does cycle when I park.

It almost sounds like there is a small stone kicking around in there that catches once in a while.

Ideas? How hard is it to get in there and remove the drum to see the pads etc? Thanks

No idea, but be careful. The shoes have a nasty habit of delaminating, and if they jam up inside its big bucks (apparently) especially if you're on the move.

If you change the shoes as well, I believe you'll need an SD3 to reset the EPB.

C
 

azapa

Member
Messages
1,300
Thanks Catman. It makes a sound just once on a while, like a few rotations forward, a few back and one scratch/grumble at no specific point.

I would imagine a de-lamination would make a constant sound, but it may just be loose.

I am thinking a small stone has got in there.. do i dive in myself or throw the MD some cash - that is the question..
 

CatmanV2

Member
Messages
48,547
Thanks Catman. It makes a sound just once on a while, like a few rotations forward, a few back and one scratch/grumble at no specific point.

I would imagine a de-lamination would make a constant sound, but it may just be loose.

I am thinking a small stone has got in there.. do i dive in myself or throw the MD some cash - that is the question..

I don't think the stone is likely but...

As far as I know it's pretty standard to get in there. As if you were replacing a rotor, so jack, secure, wheel off, pads retract a little, caliper off, rotor off.

I stand to be corrected, however, if Voicey or similar are reading.

Best of luck

C
 

azapa

Member
Messages
1,300
thanks catman. much appreciated. I am nervous around those carbon ceramics though. I'll probably just meekly show up at the MD..
 

Razz

Junior Member
Messages
123
Hi there
I did the rear brake shoes on my QP4.7s as a result of intermittent grinding noises.
When got to the shoes I was shocked at how scored and crumbly they were on both sides.
It is something that can be attempted by oneself and support from the forum.
Or a good indie can sort for a lot less than main dealer.

Best to have it seen sooner rather than later.

Razz
 

sofasurfer

Junior Member
Messages
398
Had a grinding noise occasionally when hard turning left. At Emblem they diagnosed that the EPB shoes had started to crumble and needed to be replaced. Hopefully it's that and not the ceramics.
 

CatmanV2

Member
Messages
48,547
Had a grinding noise occasionally when hard turning left. At Emblem they diagnosed that the EPB shoes had started to crumble and needed to be replaced. Hopefully it's that and not the ceramics.

I think the drums for the EPB are not carbon ceramic? I assumed they were a cast iron / steel bell. Totally might be wrong though.

C
 

azapa

Member
Messages
1,300
i think sofa's thinking maybe the grumbling is coming from the ceramics themselves, but I have checked all and see no signs of scoring.

In Razz and Sofa's case, how old and how many Miles were done? Mine has 12K miles now, but is a real garage queen and is has hardly even been driven in the rain. Maybe 3 days ever? Hard to imagine the EPB shoes crumbling??
 

FF1078

Member
Messages
1,123
I had this on my last GT/s
It ended up being a clip that holds the hand brake cable had snaopped and the cable was rubbing on the disc under ecrtain conditions. Usually after just setting off or driving slowly in town.
Inexpensive clip and an hours labour charge at MD
 

voicey

Member
Messages
660
My advice is to get the discs off and the shoes checked before it causes expensive damage.
 

sofasurfer

Junior Member
Messages
398
i think sofa's thinking maybe the grumbling is coming from the ceramics themselves, but I have checked all and see no signs of scoring.

In Razz and Sofa's case, how old and how many Miles were done? Mine has 12K miles now, but is a real garage queen and is has hardly even been driven in the rain. Maybe 3 days ever? Hard to imagine the EPB shoes crumbling??

Mine was about 22K when it needed the EPB shoes replacing. Mine was used as a daily driver and used in all weather conditions. When I bought the car it had 12.5K on it and was sat in the showroom for a few months with I'm guessing the EPB left on for a long time. I get in the habit of switching it off if not needed now. I would get the back wheels off and have a look as other have said.
 

azapa

Member
Messages
1,300
Mine was about 22K when it needed the EPB shoes replacing. Mine was used as a daily driver and used in all weather conditions. When I bought the car it had 12.5K on it and was sat in the showroom for a few months with I'm guessing the EPB left on for a long time. I get in the habit of switching it off if not needed now. I would get the back wheels off and have a look as other have said.

Thanks for the advice, all, Voicey. I saw on the other forum some howto's on the ebp shoe change, and it seems quite easy. I really should man-up and give it a go. Just a look at least. The cca disks have no ridge, and spin really freely, that means the calipers should come off quite easily without prying (gulp).

If i go in there I'll take a few pictures..
 

azapa

Member
Messages
1,300
Warning: gratuitous brake **** included.

So I dove in there. Everything came off and went back on easily. You can hear the original grumble/scratch sound in the video (turn up volume). I sanded the shoes a little and polished the hub. The sound has now completely gone, but there is something I just don't get: how can rear parking brake shoes show wear like this? I mean, they are only used when the car is stopped. maybe a couple of meters of rolling. How can they show wear like regular drum brakes?

I am guessing grit gets in there and causes this, and/or the shoes were set up too open by default. I was tempted to wind the adjusters back, but did not. I will be checking the other side too. ****, I even would consider deleting them all together, they are a waste of time in my usage scenario.

Farting around, as one does, I even weighed the disks, they are way within specification. Well, my car has only done 11k miles.

[video]https://youtu.be/6RJaMZPyH2Y[/video]

polished1.jpginner-wear.jpgshoe-wear.jpgWeight.jpg
 

bigbob

Member
Messages
8,952
Without a recent calibration certificate for the scales you used how do we know you are telling the truth? :thumb1:
 

conaero

Forum Owner
Messages
34,593
Did you use the scantool to retract the automatic hand brake and put it into service mode or did you manage it without?

I need to check mine so do tell.
 

CatmanV2

Member
Messages
48,547
Looks to me like they've been a bit snug to the drums. Perhaps the EPB needs calibrating. I guess Voicey could answer for sure.

C
 

azapa

Member
Messages
1,300
Wow great pictures, Thanks for posting.

Was it a difficult job to remove?

It was really easy. I have a ton of tools and stuff though, in my workshop. Polisher, compressor, stuff like that. But a quick Halfords visit would do. A 10mm (I think??) hex head socket will be needed for the caliper bolts.

Care must be taken around the brittle carbon components. Just taking the wheel off wrong could cost you 4 grand in disks if you drop it in the wrong place.