I decided to take the calipers apart to check the condition. I managed to do this to the piston.
I then decided to try that electrlytic cleaning on the main bit of the caliper. A lot of rust did come off but the inside of the cylinder presumably
should never have come in to contact with the water and is now ever so slightly rough rather than the silky smooth it was before. Are they still
usable or should I just bin them and buy some more?
Cheers
You could bung 'em back together and get some exchange reconditioned calipers from Brakes Int.....at about £40 each.....
http://www.brakesint.co.uk/
Front brakes have got to be the most important part of any car...
Like said I would slap them back together and get exchange units...
£40 a side is a small price for piece of mind ,and thats what ive done..
I polished the pistons untill I had gone through the chrome trying to remove the pitting
cheers for the advice. I'll do that then. No point in having a car that doesn't stop.
I wouldn't be that hasty myself...
Firstly - electrolysis does not effect clean metal (only rust) so machined surfaces like bearing seats, caliper cylinder bores etc will not be
damaged. The roughness you have is probably a tiny amount of oxidisation caused by the water drying, or just residue from the electrolysis tank.
Just clean the bore gently with a brillo pad type thing (maybe the ones suitable for teflon pans) and some brake fluid, or even just kitchen paper or
something. Electrolysis wont have damaged the bore. The surface finish of the caliper bore is hardly critical anyway IMO (to the degree we're
talking about here).
Secondly, looks like the notch you've taken out of the piston will be above the seal in the cylinder even with the piston pushed right in.
You'd need to check, but if that's definately the case then that dont matter either. All that matters is that the seal can do its job
properly.
At the end of the day though you have to be comfortable with your bits!
Liam
Hmmn. The surface is certainly not badly damaged at all. Just not as smooth as previously. The seal was obviously good before I took the thing apart
as there is no pitting or scoring of either the piston or the bore. I think you're right about the notch being ahead of where the seal will be.
It's interesting to hear that the surface finish isn't critical so I might actually try cleaning it and see what happens.
If I put it together and test it and it leaks I buy another one from brake international otherwise just use it as is.
I will definitely be ordering some refurbishing kits from them though. And those springy metal bits and some nipples so the link was certainly useful.
It is obviously important you're comfortable with your bits. Otherwise you're just rummaging round and scratching all day.
Thanks for a different view point Liam.
Seeing as you seem to know something about this electrolysis lark I've got another question for you.
Am I right in assuming that it doesn't matter as much if the cathode goes in the water? I know it's the anode that gets eaten away and so
the positive terminal from the charger should be kept out of the water.
I had a bit going overnight and it fell over leaving the negative charger clip in the water. It doesn't seem to have been eaten away but it would
be nice to know for certain.
Oh, one more thing. I'm getting green gunk as well as rust forming on the cathode. Is this expected? I had a read of the electrolysis thread and
found someone complaining of the same problem but no answer.
And no my anode isn't stainless steel and the water hasn't gone yellow. Green and brown instead.
IMHO...
Brakes, steering, and suspension parts are what I call "Mission Critical" parts.
They are fundamental to your safety.
How much is your life worth? (and that of your passenger / Son / daughter / wife etc)
What ever you end up doing... Make sure its 150% SAFE and done correctly.
Personally I would never use any part in these areas that is even slightly dubious.. Your lives may well depend upon it doing its job properly.
I will only ever use Manufacturer boxed, or OEM parts. I wont even use Pattern Parts in Mission Critical areas.
Its false economy to do anything else.
quote:
Originally posted by wilkingj
Its false economy to do anything else.
If you are asking the question then you must have doubts. In my book doubts over brakes are not good.
I got exchange recon calipers from local motorfactors for about £28 each (fronts). Not worth the hassle of overhaling old ones yourself imho.