About to change discs and pads all round...

[shorn]

Hi all,

As per the title I am about to replace the front and rear discs and pads on my Mk1 Leon TDi 130. Picked up new discs/pads today from GSF, and also nabbed a caliper piston wind back tool from Halfrauds.

Whilst I was in there I picked up some new Brake Fluid and an Eezibleed system.

My plan is first and foremost to change the discs/pads, (this will be my first attempt) but from what I've been reading, it doesnt appear too difficult.

Providing all goes well, I decided it would be a good idea to change fluid as well, as current fluid has been in there for well over two years.

I'm less confident about bleeding the system and replacing the fluid than I am replacing the discs/pads all round, but I really want to give it a shot.

Just wanted to know if theres any tips anyone can give me before I set myself on it first thing in the morning!

Also I've been reading about bleeding the brakes, and cannot seem to come across a definate answer as to what order to bleed them in. Also, I am not sure if ABS will have any implication? (Will be replacing with standard Dot4 Fluid, via the Gunson Eezibleed)

Any help, tips, thoughts, suggestions all welcomed!!!

 

[RickC]

start with the furthest away from the brake res and work to the closest, so pass rear driver rear, pass front, driver front, do it 2 times. also do not over pressureise the easy bleed, think its 15 20 psi max it will say though. also use a ring spanner not a C spanner or adjustable or you will end up rouding the bleed valve off is they will be tight.

 

[shorn]

Great, thanks for the tips! Also I've been reading about the possibility of the handbrake needing adjusting once the rears have been done, is this the case?

Also, copper slip/grease, where to apply it??

 

[RickC]

Great, thanks for the tips! Also I've been reading about the possibility of the handbrake needing adjusting once the rears have been done, is this the case?

Also, copper slip/grease, where to apply it??

forgot to say bleed with handbrake off,

use a wire brush to remove old brake dust and crap, then make sure the pad slides freely, apply copper to the back of the pad and where it slides along the caliper, dont get it on the friction side of the pad.

 

[shorn]

Thanks again for that

The pads that I have, have 3M stickers on the back, once peeled off will have a sticky surface, shall I apply copper grease over this or scrub that off?

 

[RickC]

no, just make sure the surface you are sticking the pad to is clean.

 

[CupraUK]

Be careful when undoing the bolts on the rear calipers, I slipped on it and sheered the brake line that crosses the rear axle.

 

[BBoy82]

If you have a compressor, make sure you wear a dust mask, and use an airline to blow clear the ABS sensors and rings. Dust and crud blocks up the perforations in the ring, and the result is trigger-happy ABS, or buggered sensors!
Not what you want!

 

[shorn]

thanks for the extra tips! first quick ? though,

whats the best way to get the retaining clip out? it seems pretty wedged, but i dont want to bend it out of shape trying to force it!

 

[shorn]

Right not too worry, clips out, but the caliper seems planted! Quite tough to remove, both bolts are out, is there anything else I can do to help ease it out?

 

[CupraUK]

I use a club hammer

 

[shorn]

OK, first disc and pads have been replaced. Now all the caliper is back and bolted on, there is a bit of play in the pads from where the piston was wound back, Im assuming that once eveything is back together (i.e. wheel on) then it will tighten up when the brake is depressed?

Theres also another thing thats bugging me... The brake disc doesnt seem to run in the centre of the carrier, its more towards the rear of the carrier. Should it be dead centre?

 

[JamesL]

yeah once you depress the pedal a couple of times the pads should correct the way they are sat.

Not sure I understand what you mean about the disc position? As long as you put everything back where you found it, there is only way for it to fit all together, so it should be ok. Pics would help though?

you're going to have a fun few days of driving, new discs, pads and fluid all round!

 

[shorn]

OK, piccys here...

As you can see the disc runs very close to the fixed carrier. It looks to be very close! Looking at the old disc compared to the new the height of the new discs hub seems to be a tad higher than the old discs, therefore pushing the disc back further bewteen the carrier.

 

[shorn]

Old disc for comparison...

Old and New together (i think the hub part looks deeper on the new??

 

[JamesL]

it does marginally, but not sure there's anything to be worried about. I'm no expert but I think its ok, I seem to remember reading somewhere that rather than both pads squeezing the disc, one pad pushes the disc against the other - hence there would probably be a bit of bias front/back?

Hows the rest of it gone mate?

 

[S3 AKR]

Did you have to do anything with the handbrake once the new pads were in ? Doing mine tomorrow on the rear.

 

[shorn]

Well there going back to GSF on Monday, what a waste of a day!, I finally found a torch to get right behind and have a look, and the disc is rubbing up against the carrier! The hub is definatley deeper on the new ones. Pain in the ass as well as I had this weekend set aside for it!
This is the second time that I've been a bit dubious about GSF, last time they gave me 505.00 instead of 505.01 oil. Doesnt say much for a VAG parts dealer.

 

[Markyboyt]

Well there going back to GSF on Monday, what a waste of a day!, I finally found a torch to get right behind and have a look, and the disc is rubbing up against the carrier! The hub is definatley deeper on the new ones. Pain in the ass as well as I had this weekend set aside for it!
This is the second time that I've been a bit dubious about GSF, last time they gave me 505.00 instead of 505.01 oil. Doesnt say much for a VAG parts dealer.

Was it rubbing on the caliper carrier or the caliper? and also had you pumped the brake pedal at that point?

The reason I ask is that if its the caliper itself and you havent pumped the pedal then the caliper won't be sat in the position it will be in for use.
As the outer pad is in a fixed position on the caliper, a large gap between the pad and the disc will mean the caliper is sitting too far forward (outwards) so the back may well catch on the disc. Once the brake has been pumped up the gap will be taken up and the caliper will move inwards and as the pads wear will continue to go inwards as the calipers are floating.

Obviously if you had pumped the pedal and everything then ignore what i said above but I would be surprised if that was the case, I would think the few mm further back that the discs sit could easily be compensated for by the floating caliper but only you can be the judge of that.

hope you get it sorted.

 

[shorn]

No it was actually rubbing on the carrier, the caliper was fine and moved freely back and forth but the rear of the disc was actuallyvsitting against the back of the carrier (the side where it attaches to the hub. There was defo something off with it! Back they go!