S2, front disk and pad replacement

[zcacogp]

Chaps,

Maybe this is the first contender for an FAQ thread, here goes ...

I need to replace the disks on the front of my S2. The manuals say that new disks are 28mm thick, and minimum thickness is 26.6mm. So, 1.4mm wear allowed.

I measured the size of the lip on the outside of the outer face of one of the disks on my S2 last night (easy to get to, just poke the vernier through the lovely D90's *) and took five readings of between 1.05 and 1.15mm. So, double this (two sides) and this suggests that I have total wear of over 2.10mm. So, the disk is past it.

New disks and new pads are therefore order of the day. So, some questions:

1. The manuals seem to suggest that it is a simple job replacing the disks and pads. Pads don't worry me, but the disk is a case of caliper off - two retaining screws on the front of the disk off - remove disk - replace disk - screws in - replace caliper - fit new pads. Is it really this easy?

2. Is it worth having a look at the adjustment of the hub while I am in there?

3. How long to front disks last? I know this is a "how-long-is-a-piece-of-string" question, but the car has 140k on the clock and I can't see anything in the history that suggests the disks have been changed. Is this possible?

4. I have ended up with Mintex pads. Are they OK?

5. What is the recommended procedure for wearing-in pads and disks? Should I avoid hard braking for some time, or actively seek to bring the car to a sharp stop from a high speed to bed them in?

All advice appreciated! Thanks ....


Oli.

* - For Nick, just to underline my appreciation for the D90.

(Anyone who mentions Seat's, diesels or welly boots in their reply will incur my eternal wrath. I hope this is clear. OK?)

 

[sawood12]

1. Yes, it is a simple job. I have a load of cable ties which I daisy-chain together and hang the calper off the front spring. The two retaining screws on the disk can be a bugger to remove, so might be worth having an impact driver at the ready.

2. Not sure what you mean by adjustment of the hub - but i'd say yes! My indy checks my hubs as part of the cars annual service so i've never had to worry.

3. They don't last 140k! Even if you were the lightest braker in the world they'd corrode through lack of use before you got to 140k. I guess you should expect at least 30k miles of normal road use? Say 3 years?

4. I think Mintex pads have a good reputation and in previoius 'which pad' threads Mintex has regularly been recommended by several people.

5. I think 'breaking in pad' procedures are a load of hype. The fact that so many people advocate such a wide variety of procedures that they swear works for them proves it. And of course all of them have been divulged in secret by a mate who works in F1! Just drive your car normally for a few hundred miles or so to allow initial wear in so the pad surface shape wears to the disk surface shape to give you full engagement of the surfaces before you start any heavy braking. If you start heavy braking from new I worry about hot spots due to pad and disk surface shape mismatch meaning you don't have a uniform braking force distributed accross the pad surface. This can lead to disk warping.

 

[xenon]

Short 'n sweet:

1. Yes
2. Eh?
3. No
4. Yes
5. What Scott said.

[]

Re. The retaining screws - a dollop of wd40 a few days before doing the job works wonders. I had an impact driver at the ready but they came out easily, whereas my wife's 3 year old Mini was a nightmare.

 

[zcacogp]

Chaps,

Thanks - good consensus of opinion there (2 replies, both of which agree with each other.)

I take back my comments about the disks not appearing to have been changed - a more careful look over the service history shows that they were done (with the front pads) at 107k miles (by an OPC, at terrifying expense!) Now at 141k, so 34k miles; Scott's guess was remarkably accurate - thanks. (This does seem like quite a short life for a pair of disks tho'. And only one set of pads - usually I'd expect pads to last 2 or 3 times as long as the disks - are my expectations wildly out?)

I'll take some piccies of the job as it gets done and post them up here.

Thanks Scott and Ian for your help.


Oli.

 

[xenon]

To be honest I don't think 35000 miles is too bad for discs if you drive enthusiastically. It's not great but I got through a set in 9000 miles in my old Astra....[8D]

Try and avoid Zimmerman discs - reputation for warping.

 

[zcacogp]

Enthusiastic driving; yes, but alot of those miles have been done in commuting 'round the N Circ, which is a journey I always do carefully (can't be done with wasting petrol or mental energy when going to and from client sites.) Mind you, quite a lot of it has also been done in enthusiastic trips 'round Scotland, N Wales and Shropshire, and also quite a lot of in-town driving, all of which will be hard on the brakes.

Disks are whatever Bert delivers. But I did ask for anything but Zimmerman, and (I think) he stocks Sebro. I'll find out tomorrow.


Oli.

 

[zcacogp]

Chaps,

Thanks for the input. Job now done - and it wasn't hard. Checked the front wheel bearings as well, and both were correctly adjusted (according to the factory manual) so no worries there.

Running in the new pads and disks at the moment, so am going fairly carefully, but it feels better than it did before.

Only snag was that I completely forgot to take any photos!

Thanks for your input.


Oli.