Caliper work

[diabloam]

Hey all, I work offshore so my 86' Turbo sits for periods of up to to three weeks while I am away. When I was home last my drivers side caliper was showing certain signs of siezing, so I reckon I am going to have to strip them when I get home off this job. Whats the parts I need (plates, springs etc), where is the best place to get them and whats the job involve as although I put braided lines on for MOT couple of months ago I aint done anything to calipers and keep reading that its a bit of a mission to get these so called plates out etc, any advice greatly appreciated from all, cheers

 

[morris944s2john]

When are you planning on doing the work?? If you can wait a while I'm going to do an on-line guide complete with photos and text on how I rectified the plate lift on the callipers of my 1990 S2.

The work is not that hard but there are a few tricks and things to bear in mind.

 

[diabloam]

Just home, so might start it in next couple days. The big springs, which way do they come out, do I just remove these and tap pads out etc. I am thinking might not need parts, just strip and clean and get rid of any white powder (rotted alloy) clena behind the plates. Are the plates screwed in, if so what fitting is it a torx or allen key or something. Keep us posted on how you get on also John, be well interested, will take some pics myself if it helps with the how to, any further advice appreciated all. Went for spin in car, leisurely one didnt really brake much but could hear them rubbing, although at least I didnt roast them this time (think it boiled fluid last time), cheers

 

[diabloam]

Well took pads out and cleaned them up, I do have a bit of plate lift so probably going to have to address this further down the line, but that caliper isnt sticking at the moment so all good. Had a wee look at the plate retaining bolt, it looks highly unlikely to move easily. Whats the program with removing them, is it true you heat them up first to remove loctite thats applied. I take it if that fails to get it moving you have have to drill them out. Whats everybodys experience of this before I start on them, thanks all

 

[paulf968]

best trick if you fail to get the plate screws out is to weld an M6 nut onto the top -- should then come out quite easily with the application of some heat

paul f

 

[zcacogp]

The screws are the problem. Sometimes they can be a real pain to shift. The worse the corrosion, the more tightly the screw will be held AND the less screwhead will be remaining to grip onto ...

Advice seems to be to heat the screw if it won't shift (take care not to cook the caliper piston seals.) I found that if you cut a slot in the top of the screwhead (to allow you to fit a long screwdriver into it) then the vibration of the cutting loosens the screw a little; I had one that wouldn't move for love nor money, so I cut the slot, put a large screwdriver in, and it turned with very very little force at all.)

DON'T try drilling them out. The screw is harder than the surrounding aluminium of the caliper, and if your drill wanders even fractionally off the centre-line of the screw then it will disappear into the (softer) aluminium very very quickly, and the caliper will then be scrap. If you get to the stage that you simply can't shift the screws then send the calipers off to be professionally rebuilt.

When you re-assemble, you can use standard M6 bolts with hex heads. This DOES work, and the pads WILL clear the heads of the bolts, making it much much easier if you need to do the job again. (I used marine-grade stainless steel bolts as well, so they won't rust.)


Oli.