Brake residual pressure valves??????

[NTEL]

Since installing fairly large 4 pot brake calipers to the front of my TVR tasmin racer, the pedal is now long and "spongy". I've put up with this for a while and just can't get on with it. Before I go down the route of installing a large master cylinder and servo unit I was thinking about fitting residual pressure valves. Has anybody else used these to overcome a similar problem?

[Scuffers]

NTEL said:

Since installing fairly large 4 pot brake calipers to the front of my TVR tasmin racer, the pedal is now long and "spongy". I've put up with this for a while and just can't get on with it. Before I go down the route of installing a large master cylinder and servo unit I was thinking about fitting residual pressure valves. Has anybody else used these to overcome a similar problem?

yes I have used them, but it's not going to solve your problem.

you have changes the ratio of MC to calliper (hydraulically), you need to redress the balance...

worth also remembering that this will have reduced the (relative) pressure to the rears, so your effective brake balance will have moved forwards somewhat.

[NTEL]

Thanks for the replys, I thought as much. I was trying to save a bit of time and money. I have got my hands on a servo unit and a l and 1/16" MC off a subaru Impreza. Doing the calcs it would appear that this should be spot on. I'll fit them at weekend.

[Graham]

which brakes have you put on? I've got ap 4 pots and 304mm disks on my taz and didnt have a problem.

Im actually looking though at changing the pedal box to give a twin m/c setup onthe brakes and dumping the servo all together..