405/406 Drake discs

[412usa]

Does anyone have a source for the 406 discs as used on later 405's with Dunlop calipers. I know it's a long shot but is there a cross

[Nick Challacombe]

I think these are the same as my 407 looking at the part numbers. They also fit an XK 120 and many early Jaguars.
Amongst other late 50’s and 60’s cars.
My parts are obtainable from Past Part in Bury St. Edmunds, Suffolk, UK.
4 Chase Road, Bury St. Edmunds, Suffolk, IP32 6NT
Email, restore@pastparts.co.UK
Www.past
Sorry web site PastParts
















Example Dunlop Rear Caliper rebuild and return £86.40

Hope this is useful they have supplied most spare parts for my 407.

[David C]

I believe BG developments in Bromsgrove have done these in the past. I knew the 406 shared callipers with some Jags but hadn't heard they also shared discs.
Please confirm when you know.

[412usa]

Hi Nick, Yes,I can get the calipers from the XK140 but I'm not sure if the diameter and offset od the discs themselves are the same as the Bristol. I can have the bolt holes drilled and even the diameter reduced but id the offset is wrong or the diameter is smaller then they won't work. Moss Motors in the US has the Jaguar Discs but shipping to Vancouver and then haveing to return then if they are wrong is a bit of a pain.

[Nick Challacombe]

Might I suggest that you email graeme.payne@cbcpc the newly set up Classic Bristol Car Parts Company who now hold all the stock of Bristol Spares that were with Bristol Cars and Graeme was parts manager at the now defunct Bristol Cars. Brian Marelli the fountain of all knowledge Bristol wise is helping out a couple of days a week.
I anyone know then they do, or know who to ask.
At least with email you should get a swift answer. The company was set up by members of the Bristol Owners Club with some very generous help I understand.
The front and rear discs on my 407 have 406 part numbers.
Kind regards,
Nick

[412usa]

Thanks Nick, I texted CBPC a few weeks ago. I know they are busy following the move but I will try an email.
Regards,

Peter

[Geoff Dowdle]

412USA,

I have two sets of 406 front discs fitted to my two 400s , one with Alloy Coopercraft 4 piston calipers, the other with Girling #17 cast iron Calipers.
Both work well compared to the standard drum brakes . A great safety feature driving a speed keeping up with today's traffic

Measurements of the 406 front Disc compared to a used/worn Britannia front disc

406 OD 11.25 inch , Britannia 10.875 inch
406 Offset 34mm , Britannia 28mm
406 thickness 13mm , Britannia estimated 13mm
Overall height when laid flat 406 47mm, Britannia 41mm

Brake Disc Rotors are available ex BG Developments/Bromsgrove UK HOME
406 Front BGD3993
406 Rear BGD4197
407 Front BGSD 121-10
409 Front BGSD 136-11B
411 Front BGSD 50-10
411 Rear BGSD 50-11

As you can see all the listed discs must have different dimensions .
I hope this helps .
Geoff

[412usa]

Thanks Geoff, Great information. I wrote to Moss Motors in the US to size the Discs they had for the XK140 but they are 12 inch Dia. 3/8 thickness and 2 inch offset

Regards,

Peter

[412usa]

As an update to this thread. I have 406 discs, which I bought from CBCP but am still having problems finding appropriate calipers. Can't seem to contact Coopercraft and BG Developments only want to sell both the discs and the calipers as a set. I'm in the UK from the 4th to the 13th of September, going to Beaulieu and Goodwood, and would like to source a set of Calipers when I am there.

[Geoff Dowdle]

Peter,
I heard that Coopercraft have closed permanently , which is a shame . I suggest you contact a Jaguar Specialist and get the measurements of a early XJ6 caliper which have three pistons and a large pad. These calipers are for a solid, non ventilated disc rotor and commonly fitted to XJ6 S1, some Ferrari, Lotus, AC Cobra and 410 - 411 Bristol
The fixing bolt spacings of these are 3.5 inch which is common on many Girling calipers

When I fitted the Coopercraft 4 piston alloy calipers to my first 400 I had no caliper carriers . It was not too difficult to make a caliper carrier to set the caliper in the right position and right offset to suit the disc .

There is surely other companies that offer XJ6 S1 replacement alloy or cast iron 4 piston calipers.

Both of my 400 have 406 disc on the front, one with Coopercraft 4 piston alloy and the other with Girling #17 cast iron calipers, used on Humber Hawk & Snipe 1960 onward .These have two large pistons of 2.25inch diameter but a smaller pad than any 3 or 4 piston caliper.

Geoff

[Geoff Dowdle]

Peter,
I searched Amazon US , they have replacement 4 piston calipers for XJ6 S1 left hand and right hand at reasonable prices . They look to be cast iron not Alloy.

Geoff

[412usa]

Hi Geoff,

Thanks. Would these have the right offset or are you suggesting that they can be shimmed?

[Geoff Dowdle]

Peter,
You might have to shim it or modify the caliper carrier to make this caliper fit perfectly .
As I mentioned I did not have caliper carriers and made them so the pad located correctly on the disc
and welded a flanged sleeve with threaded internal hole so it is not necessary to uses shims on the fixing bolts .

What is the distance between the centres of the fixing bolt holes on the Dunlop calipers ??

Geoff

[412usa]

Geoff, The bolts are .5" and 2.9" on centre. The distance from the back face of the mounting bracket is .72" and the disc is .5" thick..I have ordered a caliper, that is supposed to arrive on Tuesday so I can see if it might fit before I go to the UK. It will also be interesting to see the quality. As you say, they are reasonably priced.

[412usa]

Geoff, The Amazon Caliper did not fit. The bolt spacing did not work. I was fortunate to find a set of Coopercraft 4 pot calipers at Beaulieu that fit. I haven't put the front crossmember on the car yet, so can't report on effectiveness. They were advertised as being for a MK 1 E type and I checked the bolt spacing to match the Dunlops but the fellow also had a 406 he was breaking for parts so I took a chance.