Keri-WMS

Er....... might be a idea to take it to a garage? Failing that - there should be two or three small (M6) threaded holes in the disc, these are so you can jack the disc off the hub (good thinking toyota!). Just grease them and wind bolts in, tightening them a bit at a time, alternating with giving the disc a "tap" with a large hammer. Keep upping the torque on the bolts and the size of the "tap" and in the end the disc will jump off the hub.

Drum brakes are more effective than rear discs...but the discs won't overheat. Most cars have to shift the bias to the rear if they have discs instead of drums. BUT...if you HAD drums but changed to discs you'll get a shift to the front as a result, which is what you want if you've got more grip (bigger/stickier tyres). The one I would really avoid is fitting drums to a disc-rear car (luckily no-one wants to), as you'll have waaaay too much rear bias and will be sideways into every corner!

Drums are normally the most torque you'll get for a given size (as the friction is all nearly at the outside diameter which in effect gives you a longer "lever") and as many drums are self-energising (which uses the rotation of the drum to increase the force on the shoe for "free", similar to how a servo creates extra line pressure using the "free" manifold vaccum). In fact if drums didn't overheat so easily they would probably have remained the best bet for the front too - but they do overheat hence the disc brake. Sort version - drums give you the most power for a one-off event like hitting the handbrake!

Return them and get the right ones? Far cheaper than anything else - don't take 5mm off the carriers for sure!!!

Seconded - those discs are too big for the carriers....

Thinking about this.......NOTHING getting stuck in terms of pads/discs/piston/caliper carrier/spring clips will leave residual pressure in the line once you are off the pedal. It can ONLY be an issue with the caliper/brake line join, brake line, brake line/metal brake line join, metal brake line, other hyraulics, or brake pedal. I'd bet on a pinched/failed brake rubber hose, or a damaged metal brake line, or crap stuck in a pipe somewhere.

Could be a duff wheel bearing that's causing the heat - or allowing the wheel/disc/hub to move enough to rub the pads and create the heat? Unlikely but another thing to check.

Something very wrong with / or object stuck stuck in / the ABS unit? I would have said internally collapsed brake line but you say you have a new one....

I can modify the 254mm diameter / 55mm bore WMS 110% discs so they come with 54mm rings fitted (assuming the 54mm GT caliper takes the same disc dimensions as the EP91 does) - adds £35.00+vat/pr making them £100+vat/pr. Any help? :-) Can do grooved and (probably) pads etc too.