ST185 caliper rebuild - daft questions from the mechanically inept

[Gary.H]

Hi,

Just started the refurb of my ST185 single pot calipers but have a few (probably daft) questions as to how to progress.

Willing to accept obvious answers as spannering is not really my strong point :shhh:

Have dismantled one of the calipers and found the guide pins/runners looking pretty scored and pitted like this:

http://i142.photobucket.com/albums/r...s/DSCF0334.jpg

http://i142.photobucket.com/albums/r...s/DSCF0333.jpg

Does this mean they're fooked or can I just polish the scoring out ?

I'm also wondering how to prevent any sh*te from getting in the runner/piston bores and bolt threads when I wire brush/wheel the rust off the caliper ? Just stuff a rag down there or replace the bolts where possible ?

Atm I've left the piston and it's seal in place as it looks like a pretty good way of keeping the piston bore clean whilst sanding the rust off, good idea or not ?

Aware this kind of buffoonery doesn't qualify me to even hold a grinder :hidesbehi - but hey, got to start somewhere :blush:

Cheers - Gary

[keri-WMS]

Hi Gary - they look well past it to me, trouble is they'll attack any new bushes you might fit for them to run in... You could get them turned down slightly in the middle section ONLY, but then you'll have too much slack in the caliper.

I'm sure Toyota can supply new ones along with new piston seals and slider/bushes?

[adamh]

hello gary .. brakes international usually supply rebuild kits with guide pins included, i know mrT do a good deal but they dont usually' supply the pins, you can try them etc i'm not 100% on that. brakes international are generally more well known for supplying kits with guide pins. although, i might be abled to sort them out a tad with some diamond polish and mega rpm's if you can bring them round

when cleaning the caliper, strip it totally, dont worry about the bores getitng dirty, you really need to get them apart completely, then when finished wash thru with brake cleaner or brake fluid etc. a rebuild kit will come with new piston seals and clips etc. mate if you want to come over and need a hand one saturday its n/p you know where i am most weekends !.

[Gary.H]

Cheers Adam.

Unfortunately I've already ordered the caliper refurb kit from Mr T - without guide pins :shifty:

Will check the price of new guide pins from Mr T, existing ones are pretty deeply pitted and I'm concerned about taking a chance where brakes are concerned.

Have yet to strip the other caliper, maybe it won't be as bad :pray:

Cheers - Gary

[adamh]

try brakes international for guide pins on their own aswell, if you cant get the pins.. bring them round to me, i'll sort them out

[OlberJ]

I think i've fluffed up, thought my brakes were gonna be single piston, turns out they're twin pistons.

Is it the same refurb kit?

[adamh]

i wouldnt have thought so olber, they will be smaller pistons, needing smaller seals and clips etc, cancel the kit matey or sell it here, it'l go..

[Gary.H]

try brakes international for guide pins on their own aswell, if you cant get the pins.. bring them round to me, i'll sort them out

Cheers mate :thumbsup:

Had a look on the BI site. Looks like the pins only come as part of the caliper kit ( which incidently are £26.27 inc VAT per side - Mr T kit was £42.30 inc but that does both sides - but has no pins, as previously stated by Adam ).
Dismantled the other caliper last night/this morning (after getting back from the pub ) and the other two pins seem fine. I'm missing one of the brake pad clips as well as some of the anti-squeal shims - Toyota parts diagram for the ST185 says there should be three per caliper. Are the shims necessary ?

Anyone got any of these clips (the larger ones) or is it another phone call to Mr T ?

Cheers - Gary

ps HTF do I get the caliper pistons out without damaging them ? they seem pretty firmly in there !

[adamh]

soak the piston in wd40 to help out, makes sure seals are off, wrestle it out.. somehow lol .. all i can say is dont damage the bore wall or piston diameter.. try turning it by hand and pulling..caliper needsto be in bits for this. i probably used a blunt screwdriver under the sealing lip of the piston and levered it up.. but i was very careful and slow.. and held the caliper in a vice ...and have the facility to repair any nicks at my work place.. swiss files / lathes / polishing compounds. just careful thats all.

[keri-WMS]

People use air lines to blow pistons out but that's a tad....risky! Maybe sacrifice (cut up) an old brake hose and connect it up to a car FOOT pump via a bit of thick rubber/plastic pipe/hose etc with some small jublyclips to seal if off? Won't need to hold a lot of pressure unless it's WELL stuck and that way you won't fire the piston any anyone!!!

BTW, mineral oil/grease attacks the types of rubber they use for brake calipers seals so if you use oil get it WELL clean with spirits etc.....