Brake disks

Rotated the tyres today and while I was at it I checked the pads and shoes for wear. Pads had 4.5 mm and the shoes about 3 mm to go. I also noticed the disks were shinny all around but only about 20 mm in width, the pads are much wider than that so obviously the pads are not making full contact. Its just passed the braking test for the mot and I've not noticed poor braking at all. Can anyone tell me if this normal to have only 20 mm surface contact, both disks on both sides are the same.
Cheers
Tony.

Should be full contact. I have saved brake discs sometimes by rubbing off rust and changing the pads. But most times you are better off changing both pads and discs if there is uneven wear.
There is a percentage of minimum area of the disc that can be rusted but not sure if this applies to all countries or how big it is.

Yakuza,, Thanks... I have two sets of new pads. They measure 38 mm in width. I'll try and source a couple o' disks locally and fit them soon. I don't think 20 mm is good enough. I just wondered as both were the same and on both sides of the disk this may be normal.
Cheers
Tony.

Check that the callipers are sliding well when you change the disks...

sniper

Will do sniper... I've got some silicon grease for that..

Red grease is the best

Not sure I'll find that over here in Bulgaria maverick,,,, I'll check around though. But silicon I know I do have got to make do sometimes.

Yes Kirthynut I know... Martin has sent wheel bearings and stuff for the death wobble, and a top rad hose I needed four years ago to Bulgaria. Before I drove the Jimny over from the UK I picked up some shoes and pads and two disks in anticipation but I only do between 2000 and 2500 miles each year so I still have them along with three sets of spark plugs (I didn't realise I had an iridium set already in)
I'll be over to the UK next spring (March) so I'll pick up some red grease from Martin then and pad/shoe clips, springs etc. I plan also to replace the rubbers and bolts on the calipers next year so the silicon grease is real only a stop gap.
My jimny has to last that's why I'm keeping up with the maintenance and with the help of the knowledgeable people here and my spanners, all is going well so far.
The Jimny had 32,100 miles on the clock Sept '14 and today it has 43700. 2000 miles of that was used up just driving over to Bulgaria.