New brakes - issues?

conaero

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34,593
Whats great about these hub mount skimming machines is that it skims the discs to the fitment of the disc on the hub so you get a perfect result, probably better than when they are fitted new.

Had mine done on my GTS some years ago at HR Owen, about £260 from memory and worth every penny.
 

P R

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1,382
Yes and for a while it was ok, now they're going AGAIN, you can feel it at motorway speed braking. So that's now 1 set of semi worn discs (warped), 1 set of brand new discs (warped) and the re skimmed new discs (warped again).. all since the pads were fitted...
 

P R

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1,382
After reading this I'm now not sure whether mine have deteriorated after running them for the 3000 mile trip to Italy and back. There is what feels like a slight judder through the foot on initial braking contact. That said I didn't really notice it when I was away and braking ******* the mountain passes so maybe its my imagination. I'll keep an eye, or foot, on it and let you know if it gets any worse.

I'm not driving the Ghibli as much during the week at the moment so maybe I'll notice more when switching between cars.

Its very disappointing. I will talk to the dealer but they have an easy get out, in not getting the OEM Maserati discs fitted by them. Which is poor.. though I will give them a chance first. I suspect the pads are too aggressive?
 

conaero

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34,593
Yes and for a while it was ok, now they're going AGAIN, you can feel it at motorway speed braking. So that's now 1 set of semi worn discs (warped), 1 set of brand new discs (warped) and the re skimmed new discs (warped again).. all since the pads were fitted...

Sounds like the discs are thin and cant dissipate the heat so they warp. Another thing to try is make sure your pads are new or they transfer the warp pattern back onto the disc and that pads are not sticking in the callipers, you should file the edges so they drop in, not tap in and copper slip the guides.
 

P R

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1,382
Sounds like the discs are thin and cant dissipate the heat so they warp. Another thing to try is make sure your pads are new or they transfer the warp pattern back onto the disc and that pads are not sticking in the callipers, you should file the edges so they drop in, not tap in and copper slip the guides.

The original discs might have been worn but the brand new Maserati ones certainly weren't. Even after the cut they had virtually all their "meat" left on them.
Its looking like I will have to replace them again. The pads have barely done 20k now and the discs about 5k...
 

conaero

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34,593
The original discs might have been worn but the brand new Maserati ones certainly weren't. Even after the cut they had virtually all their "meat" left on them.
Its looking like I will have to replace them again. The pads have barely done 20k now and the discs about 5k...

Hum, not good is it. Check the pads are loose though.
 

P R

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1,382
Hum, not good is it. Check the pads are loose though.

They were very tight in the caliper I thought, but the bloke who was cleaning them (the one who did the cut) said that was normal as if not they'd rattle.
 

MrMickS

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3,951
Not so much issues but I've just had the report from the vehicle inspection on my service and my front brakes are at 70%. I've only done 5k miles on them. I must be driving 'enthusiastically' these days.

I've no idea how you can make a set of pads last nearly 50k miles. I'd have no chance.
 

RW3200

Junior Member
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295
Yes and for a while it was ok, now they're going AGAIN, you can feel it at motorway speed braking. So that's now 1 set of semi worn discs (warped), 1 set of brand new discs (warped) and the re skimmed new discs (warped again).. all since the pads were fitted...

This sounds like dodgy steel to me. Do you know who makes the OEM discs for Maserati?
The only other thing I can think of is the brake bias being well out, to the extent that the rears are hardly getting any pressure. Might be worth checking the factory figures and getting the braking forces tested to see if there's any discrepancy.

R
 

Mr S

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821
Had an issue with warped dics a few years back on my 350Z. Turned out the cause was the wheels had been painted and id fitted them without even noticing that the mounting face had also been painted, causing the disc to warp. Once if had the discs skimmed on the car, the mounting faces cleaned up to bare metal, brakes were spot on
 

P R

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1,382
This sounds like dodgy steel to me. Do you know who makes the OEM discs for Maserati?
The only other thing I can think of is the brake bias being well out, to the extent that the rears are hardly getting any pressure. Might be worth checking the factory figures and getting the braking forces tested to see if there's any discrepancy.

R

I thought it must be the discs but then the originals were fine until the new pads were fitted then they warped too.. Its in for service at the start of next month and one of the items is "brakes and calipers" so I'll make sure they give them a good looking over..
 

P R

Member
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1,382
Had an issue with warped dics a few years back on my 350Z. Turned out the cause was the wheels had been painted and id fitted them without even noticing that the mounting face had also been painted, causing the disc to warp. Once if had the discs skimmed on the car, the mounting faces cleaned up to bare metal, brakes were spot on

I saw the hub when they took the discs off to check it and they were fine.. It has then been skimmed on the hub and were ok for a few weeks, have gone again though
 

Mr S

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821
Im talking about the mounting face of the wheel, not the hub, but unless you have had the wheels refurbed, its probably something else. Il keep an eye on what you find, as my discs were skimmed before i got the car, but now judder under braking, and feels very much like the discs are warped.
 

P R

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1,382
Im talking about the mounting face of the wheel, not the hub, but unless you have had the wheels refurbed, its probably something else. Il keep an eye on what you find, as my discs were skimmed before i got the car, but now judder under braking, and feels very much like the discs are warped.

Ah right, Im with you.. well the wheels were refurbed around the same time (by dealer), they are diamond cut. Worth a look..
 

j s pollo

Member
Messages
162
Whenever you change pads you should have the disc skimmed clean out the holes and re chamfer 040 in make sure mateing faces on disc are clean and free of rust
I have been down this road and never had this problem
I drive the Mas 4.2 gt coupe I have since replaced the discs and pads new parts discs from Euro spares pads from my local spares shop using a softer pad
Front pads part number FDB 998
Rear pads part number GDB 379
Check for the min thickness for skimmed discs I have seen it mentioned some where on this forum
 

CatmanV2

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48,541
Well that's a new one. In all the sets of pads I've changed, I have never changed the discs, unless they were worn out.

C
 

rockits

Member
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9,167
I can understand that changing discs as well as pads or skimming the old discs when changing the pads is better and the ideal.

I guess it does depend on how bad the old disc surfaces were. If there are rippled or a fair off nice flat surfaces you can't expect them new pads to do the job as much as they could. If small imperfections are on the disc surface the new pads will settle in a be good enough but will still never be spot on. It is often good enough & so much better than the old pads were.

I wonder how much one of those machines is to skim them on the car? The off the car way is on a lathe I guess which is what Newton does I assume.

On a cheaper car never make sense to skim the discs as new discs are cheap enough. I guess on Maser's & other high end cars the discs are so expensive that a skim is better value.
 

P R

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1,382
Well I've booked it in with my "local" dealer for its 62.5k mile service for early Dec and have told them about the brake issue. One of the items of the service is "caliper and brake check" so I have asked them to tell me why it keeps happening. I told them it was fine until new brake pads were fitted and at the same time the alloys were refurbished.
 

rs48635

Member
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3,181
They were very tight in the caliper I thought, but the bloke who was cleaning them (the one who did the cut) said that was normal as if not they'd rattle.

This might lend a clue.
As you have replaced pads and disks, had disk skimmed they might be ruled out.
The callipers (and wheels) are the common factor. Struggling to think how misaligned wheel fitment might affect braking, but still worth a look. Hub to wheel mating surface must be flat, clean, paint and dent free. The wheel mounting flange should be clean bare metal not painted.
On my 3200 the calipers were defective causing pads to bind. This caused uneven pad wear, poor braking and heat! Temporary solution was to grind / file the edge of the pads until they glide in to place. If the pads stick in the calliper, they will remain in contact with disk surface even after the brake pedal is released.

Eventually I Swapped out the callipers and will have the old ones re-built, No more braking issues. BTW no need to get stung with OEM brake pads, there are lots of suitable alternatives. I started with a Ferodo pad which used the identical friction material and have progressed onto Green gripper and finally EBC.

my two cents - but get a trusted local mechanic to give thew brakes a proper re-assembly. Any decent mechanic will autonomically detect and fix these simple issues.