single vs. dual diaphragm booster

[sellersrodshop]

i'm putting together a 4 wheel disc setup & am curious what the performance differences are between a 7.25" dual diaphragm & 9.5" single diaphragm booster would be?? any differences in pedal feel? i like the solid pedal feel of a non power system, but having some back & leg problems kind of dictate an assisted setup.

[ProdigyCustoms]

Then forget both ideas and use Wilwoods 7/8" bore master. Exactly what your looking for, semi power feel!

I do not use 7" boosters, not enough umph! 7" booter is not enough and 9" booster is too much. We use dual diaprhram 8" boosters, found that to be the perfect compromise. But you probably will never see a booster on one of my personal cars. If you need one I have them in stock.

[Skip Fix]

A WORLD of difference between the big single booster and the smaller dual diaphragm for 81 TA 4WD. The dual diaphragm needs a pedal with LESS leverage just to keep the feel right.Speaking from personal experience swapping one on with the old single booster pedal.Stopped good but I could use my little toe on the pedal!

[Tony_SS]

My 78 came with a single from the factory. I installed a dual booster with the correct master and the pedal was hard as a rock.. it felt like manual brakes from the 60's. Later that day it got to the point the brakes just stayed clamped for some reason. I went back to a single setup.

I still have no idea why the swap didn't take... ??? I don't pedal leverage was the only incompatible part though (in this case).

[sellersrodshop]

thanks guys! i may go with frank's recommendations. the 7/8 bore m/c will require less pedal effort than the 1 1/8" bore, kind of a "tweener" between manual & boosted version.

tony, almost sounds like you had a residual valve problem with your system. it wasn't leting the fluid return back to the system when the pedal was released.