Noticed one of my front callipers was binding. Took it off and the piston is quite stiff, eased it a bit to get me by, not using the car much anyway. But so I don't have to pull the car off the road for a period of time I bought a 2nd hand set of callipers off eBay delivered for £80. There were cheaper ones but these looked in great condition... Anyway, they arrived and I'm really pleased, they're in excellent condition and the pistons move freely however, the dust covers are split. The idea was to fit these temporarily and then do a full refurb on mine, new pistons, seals, sliders etc, But I've changed my mind on my approach now, instead, I'm just going to fit new seals in these and fit them so I only have to do the job once. I've popped the pistons out and they are perfect, no need to replace them so I have ordered a seal kit. Can anyone confirm how the dust seal is fitted? There is no obvious groove, is it glued or something?
AFAIK there are two grooves inside the caliper bore, one for the sealing ring and the other for dust cover..
I agree, usually there is but the dust cover on these looks to be surface mounted over the lip if you get what I mean. I guess I'll just wait and see what comes in the new seal kit and take it from there.
caliper piston boot is little fiddly. you have to push boot up the bottom of the piston about half way up so the skirt is hanging out past the bottom of piston, locate the base of the boot into the caliper carefully then start pushing the piston in. as you go, slide the boot up the piston till it pops into the lip then finally seat the rest of the way. soak the main piston seal in fluid for an hour or so before you start, and some on piston as well just to make it easier to fit dont push it all the way in as far as it can go as you might find they're a pain to bleed if you do that, though I've only had this on the rears. but anyway, the piston only needs to go in enough so that you can slide over the pads with a wee bit of wiggle
FYI - for anyone else that gets to do this. Mk5 GTI ATE callipers DO NOT have an inner lip for the dust seal. The dust seal push fits over the outer lip. It's different to other callipers I've seen but does explain why it looked like it was external and hence my question, as the old boot had come away and looked like it was glued to the lip. It was in fact just a really tight stretch fit over the top edge. There's no groove or lip to locate it on the calliper body, just the normal groove in the piston. I did it 2 nights ago and my fingertips are still sore from trying to get the boot fitted securely without popping off. I can only assume VW have some kind of drift tool to do this job. All ready for the weekend.
I've got this same job to do tonight - great guide I'll try it. I've done the job once before and like Eddy found it royal pain to get the seal from piston to caliper with my fingers last time.
