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MG Midget and Sprite Technical - Brake calipers ruined?

I am restoring a 79 midget, and am now starting on the front end. Currently replacing the disk pads and brake lines, so I removed the brake calipers off the brake disk, but then unbolted the two caliper parts.

Naturally I then read the manual, which says "never break the caliper in half". I can see that the brake fluid has to come from the "inside" part of the caliper to the "outside" of the other caliper so both pads can be moved. So now I'm worried that I will be getting brake fluid leaks, and air intake into the brake lines through the join.

Do I now need to buy new calipers, or is there something that can be smeared on the inside joining parts of both caliper halves to make them air/fluid tight?
w butler

I've split many calipers over the years.

You need to make sure that the mating surfaces are spotless and you use a new bridge seal - 17H7679. Moss describe it as an O-ring, but it's actually a square section.

You should really use new bolts and torque to between 33.5 and 37 lb.ft. according to the BMC manual.
Dave O'Neill 2

No not ruined. I agree, not a big deal. Just fit new seals and reassemble.
Lawrence Slater

I always used to take them apart makes it easier to fit new seals and new pistons if necessary.

I have never fitted new bolts but wouldn't want to suggest that was the best course of action but I have never ha a problem.

As I say I USED to, more often nowadays I simply buy exchange refurbished items, far easier and fairly economical.
Robert (Bob) Midget Turbo

As above, I've never fitted new bolts either.
Dave O'Neill 2

Thanks very much for putting my mind at rest. I can now replace the new pistons and rings much easier - as suggested.

New bolts sounds like a great idea as well.

Thanks
Wazza
w butler

New bolts need to be the right grade, otherwise you are much better with the old ones. Sorry, I can't recall the grade off the top of my head, but very unlikely to be standard high tensile S grade, I would expect the originals to be T grade. Check the markings on the head. problem too is that the grading designation and markings have changed, so unless 100% sure you have equivalents I would suggest you are better off with the old ones.
Paul Walbran

Good thinking Paul, I'll have a look at the heads and see if there are any markings. I have kept the old bolts, and they actually look in good condition, so I always have a backup.

wazza
w butler

This thread was discussed between 02/10/2011 and 03/10/2011

MG Midget and Sprite Technical index

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