Changing pads

944cabby · Jan 25, 2009

The brake pad wear sensor light started to show up on my dash a couple of weeks ago, and i suspected i had a sticking piston in one of the front calipers again as there seemed to be some "stiffness" in the steering.
Anyways, today i changed the fronts and fitted some new mintax pads.One of the pistons in the drivers side did indeed seem to be stuck, so i freed it up and fitted the pads which slotted straight in - no issues.
With the passenger side caliper - although all the pistons seemed free,it was difficult to insert the pads - not because of tightness against the caliper plates but because the pads were tight against the actual disc, even with the pistons pushed right back into the caliper.
Took it for a careful short spin and although it felt a better drive the steering still felt heavy - is this likely to change after the bedding in period of the pads?Or should the pads sit loose against the disc?

sawood12 · Jan 25, 2009

From what I remember about this when I last changed my pads is that it is a snug fit and I have even knocked in pads with a rubber mallet. It doesn't matter as the pad will bed in pretty quickly.

Though i don't understand why you think the weight of your steering is being affected by your brakes? Fair enough if the car is pulling to one side you might suspect brakes but for heavy steering I can't see how brakes can affect that. I find my steering is quite heavy but have always assumed it is just the way it is.

nick3814 · Jan 25, 2009

ORIGINAL: 944cabby
One of the pistons in the drivers side did indeed seem to be stuck, so i freed it up and fitted the pads which slotted straight in - no issues.

Interesting! One of the pistons in the front nearside caliper on my S2 is seized/stuck, the dust boot/cover is split and has obviously let a bit of corrosion in. How did you free the piston and was it easy. I'm gonna change my pads soon if not the discs and wondered how to sort this problem without rebuilding the caliper!!

944cabby · Jan 26, 2009

ORIGINAL: nick3814

ORIGINAL: 944cabby
One of the pistons in the drivers side did indeed seem to be stuck, so i freed it up and fitted the pads which slotted straight in - no issues.

Click to expand...

Interesting! One of the pistons in the front nearside caliper on my S2 is seized/stuck, the dust boot/cover is split and has obviously let a bit of corrosion in. How did you free the piston and was it easy. I'm gonna change my pads soon if not the discs and wondered how to sort this problem without rebuilding the caliper!!

Basically, removed the two bolts from the back of the caliper so i could lift it off the disc,removed the old pads and used a small g-clamp to exert some pressure on the piston to move.
Although my pads were quite worn, the stuck piston was out farther than the other so i'm thinking the brake pad was in contact with the disc, so affecting the steering.

morris944s2john · Jan 26, 2009

If the pistons move in easily and the pads are still tight to fit to the calliper, then I'm afraid you have the dreaded caliper plate lift. Corrosion of the aluminium alloy calliper pushes out the stainless steel plates and this squeezes on the sides of the brake pads making them difficult to fit- leave it like this and the brakes will get progressivley worse and sieze. The callipers need a re-build.

Heavy steering is nothing to do with brake pads- suspect power steering problem or tracking being out (toe out) could cause heavy steering- also check your tyre pressures!

peanut · Jan 26, 2009

whenever I change my pads I scrape all the crud off the caliper pistons and thoroughly clean out the pad housing beds all round.
They need to be really clean. A smear of grease to the caliper pistons before easing them back in will ensure that no rust spots or dirt ,damage the piston seals .
Its all about being meticulous with the cleaning. Be sure to put one of the old pads back in when priseing the opposite piston back into the caliper .

morris944s2john · Jan 26, 2009

If you put grease on the calliper pistons, use red rubber grease as any other type of grease will damage the calliper seals potentially causing failure, fluid leakage and brake failure. (On the Brembo calliper, the seal for each piston is in a groove in the bore and not on the piston).

944cabby · Jan 29, 2009

Changed the rear pads today and again one of the pistons on the nearside was stuck - the pad even had uneven wear.
Went for a run after but changing them and it seems to have made quite a big change to the feel of the car (moreso than changing the fronts) and the steering is defiinately better and it's not as heavy.
The only think i'm still not happy with is when i reverse out of the garage and do a full steering lock i still have a have a "crabbing" sensation from the fronts - it goes quite quickly but it's almost as if the front wheels are locking intermittantly as i reverse whilst steering - but it's only when i first use the car.
Any ideas what would cause this?

Fen · Jan 29, 2009

Tracking on full lock; the tyres are fighting each other and one skips across the surface

I have to second an opinion I think was experessed above - the brakes will make no appreciable difference to steering. i know you say you feel a difference but I have to say I think it's "clean car syndrome" where you'd swear the car drives better after a wash when it's been filthy.

nick3814 · Jan 29, 2009

My tyres do that when coming off the drive way on full lock, sounds really odd sometimes, my last 944 did the same, must be the way they are set up! None of the other cars I've had have done it.

ashley · Jan 29, 2009

ORIGINAL: nick3814

My tyres do that when coming off the drive way on full lock, sounds really odd sometimes, my last 944 did the same, must be the way they are set up! None of the other cars I've had have done it.

mine too, thank god its not another problem I'm going to have to sort!!!

Neil Haughey · Jan 29, 2009

My 968 does it as well, my S2 doesn't and I forgot that it used to do this. Its caused by a combination of geometry and suspension bushes that are not stiff enough (likely worn). With new 968 castor mounts and new or solid top mounts it should stop, same effect in reverse adds weight to the steering when turning into corners and slows the steering responses of the car.

sawood12 · Jan 29, 2009

Yep, another here. I can appreciate the skipping sensation when reversing on full lock. I had always assumed it iwas because there is a bit of a step off the lowered kerb onto the road where one wheel drops off before the other but it sounds like it's one of those 944 "they all do that sir" characteristics.

nick3814 · Jan 30, 2009

Well I contacted our local OPC at Newcastle this morning to get a price on a set of discs and pads! We have a really good relationship with our parts centre, the best they could do (this is ordering two sets of front pads and discs as Ash needs a set too) was as follows;

£99 per disc instead of £135
£85 per set of pads instead of £110

these prices were before you added vat! Not upgrades just the regular equipment!

Gave Andy a call at Pro Max, the exact same equipment (Sebro painted discs and Pagid pads) almost half the price and including the vat, so guess who I placed the order with!!

They sounded very knowledgeable too, really good to talk to, sounded genuinely interested in their custom [

]

Fen · Jan 31, 2009

Bert Gear at Berlyn Services just quoted someone via Titanic last week for S2 disks and pads at about half what the OPC quoted.

Bert doesn't just sound like he knows what he's talking about either; he genuinely does know. He also gives up his time to be a technical advisor to the Club, even though he was treated very shabbily by them when the forum started. Her really should be everybody's first port of call outside the OPC network for parts IMO.

nick3814 · Feb 6, 2009

Fitted my discs and pads today, changed the discs no problem, putting the pads in, what a swine!! Set of standard Pagid pads, same part number as the ones I took out but for some reason the plate section of the pad was that tiny bit bigger than the old ones and was really tight when sliding it into the caliper top and bottom, ended up filing them a bit to get them to fit!

Is this a result of plate lift?? Old pads fitted without a problem.

Fen · Feb 6, 2009

Did you fit the old pads? If not what's to say they weren't filed too? Sounds like plate lift to me I'm afraid.

nick3814 · Feb 6, 2009

No Fen, the old pads were in it when I got it but they dont look filed just a slightly different shape but the same part number on the pad! The plates don't appear to be lifting, sit quite flush with the body of the calliper, is plate lift something to really worry about? Brakes have been workin fine (apart from flippin ABS but thats another story) thought I might rebuild callipers next time I change pads as I have a couple of torn dust boots and one piston was seized.

Fen · Feb 6, 2009

I guess it depends how likley it is that Pagid have changed the backing plate, or made a faulty batch. Given the known issue with plate lift I would assume that that is more likely than a manufacturing issue, but having said that if the old pads came out easily and were not filed that does suggest the new ones are not quite the same size.

Plate lift is a problem to be concerned about as eventually it compromises the brakes by preventing the pads from moving freely, either not clamping the disk properly when the brakes are used or not allowing the pads to release it properly (binding brakes). Left too long it can also get bad enough to write the caliper off.

It doesn't sound like yours is bad, and maybe you don't even have any at all, so I think you may as well leave it now until next pad change. If you do have a small amount of lift and fix it now your new pads will be too loose after filing them anyway, and I don't think it will get chronic for some time yet by the sound of it.