400 braking improvements

[Superfine]

The 400 standard original braking performance is really inadequate for modern day traffic conditions and I intend to fit to my 400 a 405 front suspension unit complete with late type 405 disc brake wheel hubs using Coopercraft 4 pot calipers. I will also fit a brake servo, brake bias valve for the rear drum brakes, steel braided flex hoses and 405 anti roll bar.

With the improved braking I feel I also need to fit the wider 405 wheels in place of the narrower.400 wheels to increase the tyre contact footprint..

Has anyone got any hands on experience of a similar upgrade on a 400 please?

I am particularly concerned that using the wider 405 wheels,. there may be. interference with bodywork and suspension. I do realise that the spare wheel cover won't accommodate the 405 wheel and tyre..

Any advice would be appreciated. Many thanks

[Geoff Dowdle]

Superfine ,
I have disc brakes fitted to my two 400's .

400 chassis 650 has a 405 front cross member with 406 discs and 406 anti roll bar .The 406 bar is shorter overall and has a kinked vertical link to give clearance with the caliper on full lock.
Wider 401 - 405 and 175 x 16 tyres fit without a problem .
On the rear I fitted 7/8in diameter wheel cylinders with the STD drums . It was then not necessary to fit a brake bias valve .
The master cylinder was modified by removing or making the valve at the front of the cylinder inoperative.
A servo/booster is necessary.
The inner wings/guards have to be trimmed for clearance with the telescopic front shock absorbers.
New flexible hoses are needed
--------------------------------------------------------------------------------
400 chassis 452 has a 403 front cross member with telescopic shockers ,
405 stubs , steering arms & tie tubes , 406 hubs & discs and anti roll bar, Cooper craft calipers .(for many years it was fitted with 405 12 inch Alfin drums and STD drums rear,which were a big improvement over the STD 11inch drums ).
The rear is converted to disc using 406 rear calipers , modified BMW rear disc 11inch and custom made caliper bracket .
A servo/booster is fitted.
The master cylinder valve needs to be inoperative.
The car now has outstanding braking , as good or better than most modern cars
--------------------------------------------------------------------------------
Another option is using the standard 400 front cross member stubs & hubs with modified rear 11inch BMW disc , custom made caliper carrier, Cooper Craft caliper , servo , brake bias valve .
This will be a major improvement to the cars braking and probably the cheapest and easiest option.

Pls advise the chassis details of your 400 ??

Geoff Dowdle
Joint 400 Registrar