Series 1 rear brake callipers

[rayloud@outlook.com]

Hi All. I've fitted a new master cylinder and it's caused my rear brake calliper seals to fail. I've had quotes to fix it which are ridiculous so I've decided to lower the rear IRS myself. Some advice please - I have new seals but with all the effort I guess it's best to be safe than sorry, so should I replace the complete callipers, or replace just the pistons? It's a 1966 series 1 with the 4 bolt on cylinders. Any advice of which option and which ones to use would be great.
SNG are quoting £117 ea for a type that comes without the retraction pin. This is what it says on SNG:
Cast iron housing, S/S piston. Does not have the retraction pin for pads as OE - this is not required as pads will retract naturally. Copper grease on back of pads will assist retraction.
You guys are great and have been of help before so here's hoping the same is true here.
Regards
Ray

[mgcjag]

Hi Ray...if your dropping the irs then well worth checking everything....so a good oppertunity for a full refurb..there,s always more that needs doing once you drop the irs......Steve

[bitsobrits]

You will likely find the rear calipers to be a corroded mess, unless the brake fluid was changed regularly over the the last 40 years...unlikely due to difficulty in bleeding the rear (top tip-fit remote bleeders while the IRS is out and you will find it convenient enough you will gladly do a fluid change every couple of years).

My car had gone 60k miles when I dropped my IRS to deal with a caliper leak. Was really surprised at the corrosion given I'd done a fluid change every two years since 2004, but no idea how the previous owners viewed that part of maintenance. After weighing the time/cost of replating/rebuilding, I went with replacement piston assemblies (Fosseway alloy-just because). I saved the crusty originals for a future purist restorer.

[Jeremy]

...and when you've finally got it all back together you may well conclude the quotes were not so ridiculous after all....

[Heuer]

[bitsobrits]

...and when you've finally got it all back together you may well conclude the quotes were not so ridiculous after all....

Yes! Agreed.

I had a pro rebuild my diff unit (probably not really required) and I redid everything else "while I was there" as the IRS had never been 'down' before. My total spend was about $3k (~£2500) and about 60 hours of my time spread over 4 months (waiting for parts, plating, powder coating). U.S. Jag specialists quoted me prices in the $10k to $15k range for a total IRS restoration, and after I was all done the $10k seemed pretty reasonable. Seems like a lot, but there is a lot to do here. So it all depends on what you want. Just a once over on the calipers? Or not having to think about the IRS again for the duration of your ownership. You will find other things besides the calipers needing attention.

[lestere]

Just drop out the IRS and fit new piston assemblies into the callipers. Not worth resealing 50+ year old units since the will most probably be worn and corroded inside. Most of the Jaguar suppliers sell them and all looked very similar to me when I replaced those on my ’66 S1. As others have said, worth checking over the complete IRS while it’s out of the car.

[mtnjag]

If you are just replacing pistons you can do it with calipers in place. I have done so on my 62 on jack stands.

If replacing calipers you can do it without removing the cage or diff by dropping the suspension. Best done on a rack bit doable on stands, and if you have the later cage easier still, out the front.