Princess Calipers

Accompanied by the sound of a chisel on slate Paul, managed to produce the following words of wisdom

Because someone said so and everyone else said "Yes, that's right" and repeated it ad nauseum. In a recentish issue of PPC it was explained why they're not really that good a conversion compared to a lot of calipers that are more easily found now. Can't remember the ins and outs, but they're not really the be all and end all nowadays.

Accompanied by the sound of a chisel on slate Doki, managed to produce the following words of wisdom

Mondeo calipers seem to be the more modern way of doing it.

Quite good in their day though, having tried the ford twin pots & the princess four pots back to back on two different cars the princess ones worked better & where cheaper. You got more piston area further from the centre of the disc on average

They're four pot and a direct replacement for some two pot types. Other than that, nothing. They're not unique to the Princess either - some versions of the SD1 use the same.

I've a feeling modern ABS systems use a deal more power assistance than older ones. So a caliper which works well with those might not be so suitable for improving an older one.

However they're also stopping larger heavier cars. The only things that matter are piston area & distance from the centre. & to a lesser extent pad area.

And the pad material. Modern pads require more effort. Which means in practice more power assistance.

The other thing of course when thinking about upgrading brakes is that older cars usually had smaller wheels than is common today. So you might well not have room for a modern caliper - even from a fairly modest car.

Well it physically fitting is a given, otherwise yoiu won;t be able to get the wheels on. Which with princess calipers & 13" ford steel wheels would involve grinding the inner rim of the weld seam :-)

Mine came off LWB Transits

I've fitted XJS discs and calipers to the front of the SD1 now so have a decent pair (overhauled with new pistons a couple of years ago) of the original four pot ones spare. But mine has vented discs which may make it a problem for an upgrade to other makes - they have a spacer between the two halves.

Spacers (also seals and bolts) are quite easily available. It's a common upgrade for older Range Rovers to widen the calipers and convert to vented front disks.