I bought some parts of a guy in Glos. off ebay and picked them up off him yesterday.He has a load of bits and pieces for sale,any way,while i was in his garage browsing,as you do,he showed me a cooling jacket off the discs."Never seen one of them before" i said."they keep the disc cooled from the engine cooling system" was his reply.
QUESTION: Are they really nessecery,i dont have them on my car?

not strictly neccesary most of them fell off in short time

however if your taking the family camping in the Alps they help !

I think (correct me if im wrong) the likes of me and sam have them on our cars, the last 3 yeara of production have them.
The bracket that tends to hold them tends to snap. Look for a 10mm threaded hole iirc at the bottom ofthe top half nearest the front of the car of the disc.

The cowlings have holes, which takes air to them.
If your car didnt have them then dont worry! Like i said the bracket snaps and scrapes on the discs!!

Ps. Anyone out there know of a way to fix it? As the bracket on mine are snapped and nearly scraping?

Debatable.

If you're hooning up and down the Alps with a trailer-tent on the towbar and the car fully loaded, then probably yes.

If you're not going to such extremes, then probably no. I've always ripped the horrible rattly broken things off any car, and I've never cooked the brakes on any two-pot.

They were fitted as standard to any and all disk-brake 2cv or Dyane. I dunno about early wrong-way-round-caliper disk Amis, though.

ive persoanlly left mine on, as i thought, there there, not scraping, and left them for good measure!

Well I nearly went off the road coming down a mounting in Australia, when the master cylinder failed due to overheating of the disc. You do need them in hot climates otherwise no.

How does overheating of the disk cause the master to fail?

Surely the pads would gas up long before LHM boiled? Normal DOT fluid boils WAAAAY before LHM, even when new, and drops rapidly once it's been in the car a few years and absorbed moisture.

The Ami Super _really_ needs the cooling ducts - I managed to set fire to the pads in that once, but the fluid was still fine.

Lack of cooling will transfer the heat through the LHM and the pipes to the master cylinder and the seals fail sending the pedal to the floor. Seen it plenty of times but only in hot conditions. Not a worry in our part of the world.

always assumed the pedal to the floor was because the fluid had boiled and turned to gas, gas compresses

a cooling off and a quick bleed and the master was working fine for next 9 yrs and still is with no problems master end of the system
(the first few pumps resulted in green foam rather than fluid)

Where's Team Lumaca?
They had a 'boiled brakes' moment at the 24 hour, although that was triggered by someone forgetting to release the handbrake, iirc.

A quick pump through to clear the boiling fluid from the calipers and they were back in business...

ken.