Should I replace these calipers?

[Dad]

I noticed the rubber boot seals on my front brakes were perished so went ahead with replacing them only to find the cylinders wouldn’t budge. Took the air line to them and one of them came out with a loud ‘crack’ and in so doing bent the rim flange. Now it’s out you can see below it was quite badly corroded and therefore seized. Couldn’t get the other to move with the most carefully applied leverage and although careful I also knackered another flange. Even if I could restore the housings I’ll need new cylinders and worry they won’t fit with sufficient tolerance.

So the question is, do I splash out on a new pair of front brakes? What’s standard in this situation?

And is it feasible to move away from using Satan’s urine as break fluid (DOT 3) and move over to silicone-based DOT 5?

Many thanks for considering.

[abowie]

The pistons are a disposable item.
https://www.sngbarratt.com/English/#/UK ... 0piston%60

You seem to have S2 front calipers. So something like this is what you need
https://www.ebay.com.au/itm/28516559708 ... BMgoqH2sti

Looks like Moss USA have them too and also have the channel seals
https://mossmotors.com/xke-7827-front-b ... ser-ii-iii

Clean the housings, new kits and pistons and you're good to go.

Don't forget to replace the small channel seals between the caliper halves; you may need to go to a specialist brake place for these.

Check torque value for the joining bolts, scrupulously clean the threads and assemble dry.

For future reference, to remove pistons don't disassemble the caliper halves. Slide a piece of wood approximately the thickness of the disc inside the caliper between the pistons. Block all but one of the hydraulic fluid holes, then cautiously blow compressed air into the caliper.

Silicone vs mineral fluid is an endless argument on fora. To change you'd need to get all of the mineral fluid out of your system which isn't necessarily easy. I'd stick with what you have.

Caveat. If you are not 100% confident and experienced working on brake systems, get your local brake place to do this for you. It'll cost you double what the kit costs but brakes are mission critical and you really don't want to crash in a 60 year old car.

[Dad]

Andrew - *many* thanks for taking the time to provide such a helpful and informative answer. It’s a relief to know I don’t need to replace the whole unit.