Rear Caliper Upgrade - Few Questions

[Xiotis]

Hi all,

Car has failed MOT on the park brake efficiency, which I am told means rear calipers are seized up.

Has anyone successully unseized them? I was thinking of spraying WD40 on them (avoiding the pads and discs) and leaving it over night and then braking heavily. Worth a try or will I be wasting my time?

Also, what MK3 calipers do I need to find to replace mine? Must they be Golf GTI MK3 Calipers or will any Golf do? Will second hand do or should i fit new? And finally do the MK3 calipers use the same pads as the MK2 caliper?

Thank you!!

[Judderi]

I really dont think the wd40 and braking hard will do the trick.

As for the mk3 calipers, yes its your best option in the long run. You can also use mk4 ones if you get the braided brake lines to fit. And yes the pads are just the same as the carriers wont change. I think you need early mk3 gti's other non gti's will probably have drums on the rear.

[Xiotis]

Thanks very much for the info.

Can someone be specific as to which years of Mk3 GTI I can source the calipers from as I don't want to be getting the wrong ones! And knowing my luck....

Cheerz!

[redders]

think its a common problem on mk 2's, mine failed on lots of things...one of them being park brake efficiency down too 13%, so now mite be a good time to upgrade.


redders

[jimbo]

get the mk4 gti rear callipers! i did and haven't looked back. i have never had aproblem with them.
plus there should be quite a few mk4's in the breakers now and their brakes will be in much better fettle than the mk3 ones.

go on do it, you know you want to 

[Gambit]

here we go.....

early mk3 calipers are no good, they are the same as late mk2 calipers so therefore are prone to seizing - handbrake mechanism is on the outside!

late mk3 calipers are a stasight swap and have different handbrake mechanisms (internal) and therefore dont seize. you can tell the difference just by looking. the caliper will not have a spring on the outside like mk2 items

mk4 caliper are simply aluminium versions of the late mk3 calipers except with different pipe connections. so although they fit straight on you will need different flexi pipes

did the car fail on handbrake or just the calipers being seized when pressing brake pedal?

if its any use im replacing/refurbing my rear calipers this weekend (if dry) - so if you want you can hold of till monday & ill tell you how bad a job it was

[Xiotis]

Thanks guys really appreciate the info.

Jimbo, they sound great but as I am trying to keep costs down I will look for Mk3 ones so as to keep my flexi pipes.

Gambit, thanks mate - all so much clearer now!  . If you remember, please post and let us know how it went.

[Xiotis]

Forgot to answer your question!

It failed on "PARK BRAKE EFFICIENCY" it was only 12%.

I think this refers to just the handbrake but I am not sure.

[Gambit]

if its the handbrake mechanisms then you can free them up quite easy

disconnect the handbrake cables from the caliper
knock the handbrake mechanism/rachet out (of the caliper) about an inch
rub the exposed part with wet n dry untill all rust removed
smoother in wd40
then smoother again with grease
knock the mech back into caliper
reconnect the handbrake cable and give it a good working

[j_s]

Gambit is spot on with the details about the late mk3 calipers 
Doing exactly the same thing myself but rebuilding the rear beam - which means i've got to wirebrush/drill attached wire head the whole beam, replace the bushes, clean up the mk3 calipers (which i've done most of), send them away to be powder coated and then bolt it all on. I'm also changing over to a 256mm front setup which means i've got to clean up those calipers/hubs, replace the master cylinder etc etc, oh and the brake hoses are being replaced with Goodridge braided items, it's a long process