Ian C Posted July 14, 2014 Share Posted July 14, 2014 Hi all. The dust seals on my UK spec fronts have been iffy for a while (read: years) and now the front left wheel doesn't spin freely by hand, it's stiff to turn, so I'm assuming it's really time to rebuild the blighters. So, I'm lining up the bits and the info I need to get the job done. I've got the seal kit for all four calipers, it seems easy enough - for each piston there is a dust boot, a brass spring to hold the boot in place, and a pre-greased seal ring to go (I assume) at the rear of the piston. There are also four small copper rings that look like some sort of crush washer, not sure where these go, I'm assuming one per brake caliper so maybe where the brake line goes? It's been a while since I delved around that area My neighbour has an air line so I'm thinking I can use that to push the pistons out once the calipers are off the car, using clamps to hold each piston in until they are all out. Once out, I can clean them up with a fine abrasive like emery cloth (or dilute t-cut?), clean up the bores, and refit the seal ring, piston boot etc.. Sounds almost too easy, does anyone know what the gotcha's are? I'm sure I saw an exploded diagram of the brake caliper once but can't find it now, that would help. Also any sequence of reassembly would be cool if anyone has it I'll be able to work out where stuff goes on pulling one apart in the first place but it's always better to know as much as you can before diving in. -Ian Quote Link to comment Share on other sites More sharing options...
Al Massey Posted July 14, 2014 Share Posted July 14, 2014 Use wood in between the pistons when using an airline so the pistons don't pop out and to keep them even. Then split apart and take out the pistons. In your refurb kit you should also have small seals. You will easily see where they go once split. Also the larger seals seat inside the cups about half way down. And when rebuilding, I found it best to place the pistons in slightly, and slowly press in bit by bit until I could fit the dust covers and retaining ring, then pressed further in and out the two halves together again Quote Link to comment Share on other sites More sharing options...
Nic Posted July 14, 2014 Share Posted July 14, 2014 The crush washers go between the caliper and brake lines. Remove the caliper then pump the brake pedal to push the pistons out. Compressed air works if you get stuck but be careful as the pistons can eject from the caliper at speed! I used electrolysis to remove the heavy rust on my MR2 calipers, write up here http://www.mkivsupra.net/vbb/showthread.php?268930-Brake-Calipers-Electrolysis-Rust-Removal I then soaked the calipers and bolts in Hammerite Rust Remover Dip http://www.hammerite.co.uk/guide/rust_remover_dip.jsp and finally finished the calipers off with a wire brush drill bit before painting with 2K Foliatec brake caliper paint http://www.demon-tweeks.co.uk/performance/caliper-paint/foliatec-brake-caliper-paint-and-engine-lacquer Once you have all the parts cleaned up it's an easy enough job to rebuild them, I used Fuch Red Rubber Grease around the seals and molybdenum grease around the slide pins. http://www.mkivsupra.net/vbb/content.php?57-Brake-System Quote Link to comment Share on other sites More sharing options...
bignum Posted July 14, 2014 Share Posted July 14, 2014 Btw you don`t have to split the calipers unless you`re getting them powder coated.easier to leave them whole. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 14, 2014 Author Share Posted July 14, 2014 Spiffing, thank you. I checked that link earlier Nic and it didn't work on my main PC, it was a blank page. My netbook showed it just fine though . Plenty of red lube then, and I won't be cracking the calipers open - they aren't rusty at all. Should be easy if done methodically Quote Link to comment Share on other sites More sharing options...
mellonman Posted July 15, 2014 Share Posted July 15, 2014 This may help http://www.mkiv.co.uk/vbb/showthread.php?244873-uk-brake-refurb&highlight=brake Quote Link to comment Share on other sites More sharing options...
Dnk Posted July 15, 2014 Share Posted July 15, 2014 (edited) If you did take them apart you'd need extra seals that you don't get in the Toyota seal kit, they go between the the two halves, where the blue arrows are. CW sells them along with st/st pistons & pins. I clean up the pistons with 1200 wet & dry paper with WD40, if the pistons are pitted on there outer diameter replace them The calipers are also handed L and R which is cast into both halves of the caliper Brake cleaner is very useful to clean though the fluid lines once you have them apart, Halfords sell it in spray tins Look in the Brake system PDF, page BR-36 and BR-38 Use the lithium grease on the new seals when you fit them, only a small smear is req, also use this on the piston when you refit them Makes sure they are 100% clean before fitting new seals pistons etc, be very careful not to get any dirt etc in the brake runs as it gets stuck where the two halves of the caliper meet and is nigh on impossible to get it out without taking the caliper apart. I know this from experiance after shot blasting a set so be very careful. Be very careful using compressed air to get the pistons out and keep your fingers out the way Much better to pump them out whilst still on the car, if one is seized you will need some grips to rotate it to free it off enough for it to push out.BR.pdf Edited July 15, 2014 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 15, 2014 Author Share Posted July 15, 2014 Thank you Dunk and Mellonman, both of those are extremely useful Especially that bit about fitting the rings and clamping braided hoses! Quote Link to comment Share on other sites More sharing options...
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