997 Cooper brake callipers

[rdcoulthard]

We are currently assembling our 1962 Austin Mini Cooper with with the original 7" disc brakes. I'm hoping someone can provide some clarity on the brake callipers. The car is being assembled with original 997 callipers, which are mounted on the car and fit the 997 brake pads. I note in the parts books, there are three part numbers for 997 calliper assemblies, and 2 part numbers for 997 callipers themselves. The later 998 callipers have a single part number for calliper assemblies, and another for the callipers themselves. I haven't been able to find any information on the castings or casting numbers to differentiate them by. I'm hoping someone may be able to recognize the castings and tell me which version of 997 callipers ours are.

We also have a set of spare callipers, and I'm not sure if they are 997 or 998 castings. I've attached images in the hopes someone can provide some guidance here as well.

thanks!
Roy

[Polarsilver]

I have a pair of nos Lockheed x 997 Brake Calipers for 7inch Discs.
Left Front Casting numbers show = Lockheed 3242-267C + 10 DA20270 .. note the 10 seems to be stamped into casting
Right Front Casting numbers show = Lockheed + 3242-267C + 8 DA20270 .. note the 8 seems to be stamped into casting
On Rear casting the Left Caliper has casting numbers= DA20266C+ 3242265
On Rear casting the Right Caliper has casting numbers = DA2026?? + 3242265C .. ?? numbers poor to read but could be 60 maybe.
Underside on the rear casting of right caliper is stamped number SJ 13 3
Underside on the rear left casting is stamped the number G21 8 S
The 2 x Clamp Bolts in the hex heads show up their id as GKN "S"
Hope this helps ?

[Dearg1275]

Morning Roy,

The 997 over the course of production was fitted with three different callipers. The first two were of the same type and used the small round pads and retaining spring clip. The pads were GBP101 on the unipart coding. The callipers were 17H7911/7912 for the earliest of this type and 17H 3522/3523 for the later ones. They were interchangeable.

The very late 997s received the callipers fitted to the 998 Cooper and used the square type pads GBP102 and no spring clip. These were 17H8217\8218 and were fitted from following chassis numbers

Austin RHD 382832 on LHD 382843 on Morris RHD 382183 on LHD 379926 on.

My October 1962 Cooper was fitted with the small round pad type callipers. The third and forth photos you have posted show the spring clip so these are the ones correct for your car but... The GBP101 small round pads are hard to source and you may be better fitting the 998 type calliper. Pad are readily available for these.

Hope this helps.

D

[Polarsilver]

Just to add .. there is no paint or any other coating protection to these nos 997 Brake Calipers & the GKN Bolts are black and are not plated.
These 997 Calipers were just wrapped in that BMC brown grease paper which has done a very good job in resisting corrosion for the past loads of years
So if you want to be 100% original in your 997 Cooper build = Make sure there is No Caliper Paint & have un-plated Bolts just to keep the "originality police" happy

[Peter Laidler]

Just as a little aside to this thread about calipers and Lockheed. Lockheed were big sponsors of stuff, expertise and training material to universities with Mech Eng courses during the 70's and we had a couple of chaps that used to come from Leamington (?correct me if I'm wrong) for different modules. They told us that many of the Lockheed inner calipers and the outer calipers were formulated to allow the use of type A outer caliper to be used with type C inner caliper to make up a type E caliper and so on. As a good example, an MGB OUTER caliper that was used on the MGB range and on plenty of other cars too could be mated to a Triumph 2000 INNER caliper - also used on plenty of other cars. Then, when conjoined, this NEW hybrid caliper could be used on a car with wider discs. That car was the MGB GT V8. This happened to plenty of others such as the disc braked versions of other BMC/BL cars. I often wondered if any of the smaller calipers used on the Coopers and S were hybrids, formulated from others in their stocks.

These Lockheed blokes had all these casting numbers etc etc at their fingertips. One of them had the use of a test car that was fitted out with all sorts of gauges, pipes, wires and 'stuff' that they used to come down in.

[rdcoulthard]

Thanks for all the feedback! The ones we've used on our car (July 1962 build) do fit the small pads, which we have, and have the same casting information as Polarsilver's NOS set. I'm not sure though if there were different castings for the different part numbers of these "small pad" callipers, or if the part numbers reflect other changes.

I'm assuming then that the first two photos I posted are of 998 callipers. Can anyone confirm this? They have "112832C" and "DA18810" in the casting. And a "1" stamped into them ahead of the "DA18810"

And Polarsilver, while I'd love to go with full originality, they look nicer painted in silver, so the "originality police" may have to issue me a ticket!

[Traveller63]

Hi all -

Reviving old thread. I was looking at some of my 997 small pad callipers and noticed that one is drilled differently. Most have the second drilled bolted off hole close to bleed nipple - but one has it on the outer half of calliper - see pics below as to what I mean. Never come across this before????