PA 22 scott brake master cylinder

[sierauniform]

hi folks,
our piper colt 1961 fitted with disc brakes sometime in its past.original Scott diaphram master cylinder retained.braking applied through single lever rather than toes.braking almost non existent even though calipers function,disc and pads ok and fluid levels checked.suspect master cylinder inappropriate for the disc conversion.A/C on C of A.
Any ideas?

[SkyHawk-N]

Coincedently the guys in the next hangar to mine has had a similar problem with their Tri-Pacer. Check the flexible hydraulic lines for blockage.

[Them thar hills]

SU

Have the brakes always been like this or is it a new symptom ?

FWIW the pistons in the calipers may need removing and cleaning.

The Scott master cylinder was better matched to the Goodrich bladder type wheel cylinders. Because the disc brakes displace much less fluid than the bladders when they operate, the hydraulic ratio isn't the same, which means more pressure is required on the brake lever, for less braking effect.

tth