I originally posted a rough version of this in the 200/25/ZR section, but thought it better if I reposted it in here in a lot more detail as a guide, as hopefully it will help anyone thinking about doing the brake upgrade, (Hottubs guide on changing discs pads put the thought in my head)
282mm brake set ups can be found on any MG ZR 160/ MG ZS 180's, and are a straight bolt on fit, no modification is required to fit these to any Rover 200/25/MG ZR, im pretty sure these would fit 400's and other model ZS's though im not sure so will leave it for someone else to confirm.
Just to note, new 282mm discs and pads will also be needed when fitting the new callipers/carriers, you can not use your old discs and pads.
Worth mentioning is that the brake set up from a 620Ti (Which is also 282mm) will also fit, but will require slight modification to the carriers, 3mm's will need grinding off each side in the areas shown in the picture below.
The benefit to the 620Ti brakes, is that the pads are slightly bigger than the other 282mm brakes, and as such will have a larger surface area touching the discs, thus giving better breaking ( again I haven't got these brakes, so can only comment on what I have read)
I upgraded a members brakes, he had the 262mm solid disc brake set up, and he commented on just how rubbish they were.
The awfully rubbish standard 262mm solid disc brakes.
First of all I clamped the brake hose, with this little tool (Brake hose clamp, these can be bought from most Motor shops, theirs nothing special about this one).
Once the hose was clamped, I then removed the hose banjo bolt that attaches the hose to the calliper, again this doesn't require anything special doing, treat it as a standard bolt that you would remove from anywhere else on the car.
Once this was undone, and the excess brake fluid drained, I then removed the 2 carrier bolts.
Once these 2 bolts were removed the calliper and carrier came away as one unit, and I removed the old disc, by removing the 2 retaining screws that can be seen on the picture below this one.
I then fitted the new 282mm vented discs, by screwing in the disc retaining screws.
I then refitted the carrier by fixing the 2 bolts I showed earlier, and then refitted the calliper to the carrier, by these 2 bolts, one upper and one lower.
The callipers were already painted red before I was given them, and I have to say the job was shocking, as you can see the paint is all over the rubber protector, the callipers took over 4 hours to strip the old paint off and get rid of the layers of rust, before I repainted them.
I then slotted in the brake pads, i always apply a small amount of copper grease to the back of pads before I refit them, this helps reduce brake squeals, just be very careful not to put too much on, so that it could push out over the edges and contaminate the pad and/or discs, apply it with a finger to make sure.
You can see the amount of excess fluid that drained when I removed the old brakes, as the picture shows really, there isn't much excess fluid drained.
I refitted the brake pipe to the calliper, using the same banjo bolt I removed earlier, tighten the bolt to 34NM.
By this time Mick had done a runner and left me an Tim to fend for ourselves, so I couldn't take pictures of when I bled the brakes, and refilled with new brake fluid. The bleeding of brakes is very simple to do though, I used a draper brake bleeding kit that costs £6, apologies for the next advice not being more detailed but i did this a few months ago and cant remember bolt sizes etc.
I used DOT4 brake fluid
I opened up the brake reservoir cap, located in the engine bay
On the calliper itself is a little bleed nipple, these are usually covered with a small rubber cap, you can just see it in the picture below, its in the middle right hand side of the picture, just at the side of the clamp. The nipple is basically a nut, I placed the bleed kit pipe on the nipple then undid the nut a little, don't undo it too much.
Next make sure the engine is running, you will also need another person to watch the pipe connected to the nipple, and to keep topping up the brake fluid reservoir as needed.
With the above in place slowly press the brake pedal, the slowly release it, while you are doing this, the person watching the bleed tube connected to the nipple, will be able to see air bubbles coming out of the calliper and travelling along the clear tubing, you repeat this procedure until the air bubbles stop coming from the calliper (remember to keep topping up the brake fluid as your basically pumping out the fluid you currently have in your reservoir tank in the engine bay)
Tighten up the nipple nut (10nm), and replace the rubber sleeve, be careful with brake fluid it can be pretty harmful stuff.
I will warn people reading the above bleeding guide, this guide is here based upon my brake upgrade conversion, and is not the complete article regarding the bleeding of brakes on a car, if you want a complete guide pm me and ill do a separate write up for the people who require this
And finally the complete article.
If i've missed anything let me know so I can amend/add stuff, and if anyone has any questions ask away.