So we had my 1990 defender up on the ramp to give her a good look over, in the process of which my mechanic pointed out that the pads on my rear brakes seem to be overlapping the discs, the top edge of the face of the pad seems to be about 3mm higher than the outer edge of the disc, not a problem currently but I don't want to reach a point where the overlap is such that it prevents the pads from clamping on the disc. Is this normal or a case of wrong pads or just rubbish cheap ill fitting pads? Secondly, would my 90 have had rear discs as standard at that time or is it likely an upgrade, if it's an upgrade is it likely to be from a newer defender or from a similar era disco? Any way to tell? Any recommendations for a decent braking setup (I'm mainly using on road and green laning, no serious trials stuff) eg vented discs or braided hoses or is that overkill?

Standard defender brakes, provided they working fine, are perfectly good enough for dailying/green laning, what ever you wish to do in it provided your not towing a huge caravan down long hills and on the brakes all the way down like some people seem to do

I believe '90 is the year they changed it, so I guess you've got a 200TDI, in which case as far as I'm aware you should have disk rear axle from standard, don't know the different variants enough to know if theres a pad-caliper-disk combination that could end up with the pads clearing the disk though sorry

No the change to rear discs came with the 300 so yours would have had drums when new.[up to 93].
Just use good quality parts [there is some rubbish out there] and ensure that all caliper pistons are free.

I'd remove the pads and clean the insides of the calipers up. I had this on the 300tdi Disco once .. mud had got in between the pads and the caliper, forcing the pads out. Only a small amount, 3mm ish, but enough to create a similar lip on the top of the disk.

I've seen this on front and rear discs too.... usually, as above, it's caused by some crud in the way, lifting the pad out.... IMHO, just break the lip off the pad, clear the crud and carry on - if the pads are close to the end of their life, then they are so cheap this is not worth doing, and new ones are in order.

Just to confirm 1990 would have been drums on the back so you have a newer rear axle from a defender / disco / rrc

Thanks guys all very helpful, yeah there was a lot of muck in and around the calipers so that sounds likely, I'll have another look and might chuck new ones in for good measure. Is there any difference between the newer defender/disco rear axle or is it common to both?

You don't want newer than 1998 ish, when D2 came out, slight differences. Play it safe and order D1 rear disc pads, I'd say.