Now if you're talking about hydropneumatic brakes, such as the old Citroen Xantia, they didn't work at all without hydraulic pressure - the foot brake was effectively a valve which allowed stored hydraulic pressure to operate the brakesHi Robin,
How true! I had a Citroen BX with the hydraulic suspension and brakes. Start the engine and the car would go up, although you could control how high. It suffered from dud "balls", and leaky rubber pipes. Luckily, the steering was not power assisted. I replaced the balls (£££) but was scared off by the complicated
pipes enema hoses that connected everything together. I think it drank about a litre of the special fluid per week ... at something like £15 a litre. I was very glad when somebody crashed into the back of me.
Yes, no brake pedal, just a rubber button thingy on the floor. I can't remember which failed first ... hydraulic suspension, which would drop you down to about 4" ground clearance (avoid speed bumps), or the brakes, which just stopped working. Character building.
Occasionally I ponder on the
little V-belt driven pump, that sat on top of the engine. Can my memory be correct ... a pressure in four figures? Hmmm! Landy FFR engine with double crank pulley, and mount the pump where the 24V alternator sits.
But what would you do with all that pressure?
Just me, you understand, but I don't like the TRE in the middle of the track-rod.
Should I ever decide to have another S2 (I'm still yearning) and go for PAS, I would look into fitting a LHD drag-arm to the left hand swivel (so there are two drag-arms) and connect the hydraulic ram to the outer "eye" on the second drag-arm.
I have considered (but not in any depth) using the above idea, but with a power assisted rack and pinion bolted to the front bumper. Hey, that would work, in theory, using the original TRE "eyes". It might be a good idea to weld the bumper to the dumb-irons, and it would need a steering column with a couple of U/Js to avoid impalement.
To avoid bump-steer, it might be better to connect the rack to just one drag-arm, and retain the original track-rod.
Probably time to get my coat.
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