Mastercylinder chevette >< Kadett C CIH

[1000er]

is there a difference in the diameter of the mastercylinder of a chevette estate automatic and a kadett C /GTE ?
if i look at the ATE homepage, they should be the same, diameter 20,64mm. But the one i have in the chevette looks very different, maybe from an other manufactorer ?

i have the chevette mastercylinder, discs, calipers and drums from the Kadett GT/E and the feeling on the brake pedal is very weak.
i have read other thread with the same problem, is this a sympton of old age of the mastercylinder or do i have to change to the kadett part?

[Herbie_Flowers]

I'm pretty sure Vauxhall, in their wisdom or whoever was not on strike at the time, used 2 different makes of brakes Girling and ATE. As with the ignition side of the engine, Delco and Bosch, neither are interchangeable so the complete system must be used.

[Shoveitpusher]

In theory the mechanical properties should be the same regardless of make - ie a 6mm bore and 25 mm pistons will give the same leverage. the change in manufacturer will be pads and seals. saves testing and homolgating 2 cars. the look on the outside is not really relevant as long as the bore is the same and the pipes come out of the right places.

I'm not sure what you mean by weak brakes so:

is the servo working?

is the pedal hard or soft?

have you changed the pedal box?