having problems getting hand brakes to work

[stress]

I am paralyzed from the arm pits down .I am try to get hand brakes to work on a C-Moore buggy. I have a Pilot steering mounted on a C-Moore buggy with a steering quicker and power steering, so I can get to full steering lock in about 90 degree turn of the steering wheel. I am using Pilot Master cylinders with Wilwood calipers. I do not have enought braking power, I have maybe 40% of what I need. I think I need more flow volume get the calipers to work right. The Pilot master cylinder have a small piston diameter so I get a high line pressure but low volume flow. If go to a master cylinder with large diameter piston, my line pressure will go down but flow volume will up, but I think this will require more brake lever force. Right now I am pulling on the brake lever as hard as I can and have poor brakes. There is litte room between the calipers a the rim, so I do not think I room for bigger calipers. Does anybody have any ideas what I should try ? Does my thinking about bigger diameter pistons sound right ?

[Bugpac]

Sounds like you need a bigger master...

[Bugpac]

you could mount a larger wilwood cylinder down below, and run a slave cylinder off the pilot master to operate the larger cylinder, be like power brakes for ya....

[xmotorcr]

i'm in the same boat, i had to use a larger master cylinder when my hand controls were built.

i just found THIS it should have no problem pushing enough fluid since its for a road race bike running dual piston, and dual calipers

Originally Posted by stress

I am paralyzed from the arm pits down .I am try to get hand brakes to work on a C-Moore buggy. I have a Pilot steering mounted on a C-Moore buggy with a steering quicker and power steering, so I can get to full steering lock in about 90 degree turn of the steering wheel. I am using Pilot Master cylinders with Wilwood calipers. I do not have enought braking power, I have maybe 40% of what I need. I think I need more flow volume get the calipers to work right. The Pilot master cylinder have a small piston diameter so I get a high line pressure but low volume flow. If go to a master cylinder with large diameter piston, my line pressure will go down but flow volume will up, but I think this will require more brake lever force. Right now I am pulling on the brake lever as hard as I can and have poor brakes. There is litte room between the calipers a the rim, so I do not think I room for bigger calipers. Does anybody have any ideas what I should try ? Does my thinking about bigger diameter pistons sound right ?

[anasasisxenophontis]

Thats awesome that you still get into sand rails. Right on, man.

[Kludge]

Hi Stress,

Where are you located?

I have a hand master cylinder from a Polaris Victory motorcycle (big V-Twin) that I'd be willing to let you try out to see if it helps.

/Frank

[K-fab]

Smaller piston in the master cylinder makes for a longer pedal/lever throw and higher pressures at the caliper. It's the ratio of surface area from the master cylinder piston to the caliper piston(s).

Larger piston m/c will lessen the throw, but require more force to get the same amount of clamping force a smaller piston m/c can produce at the caliper.

If you need more squeeze power at the caliper, you need to go to a smaller piston master cylinder or a four piston caliper instead of a two piston caliper.

It has nothing to do with flow or volume - the displacement/movement of fluid is very little/small.

[Bugpac]

If a way undersized master cylinder is used, it will never displace the volume of 2 large calipers tho....You still have to push the large pistons out to apply pressure, and displace all the fluid are when it moves.... what is the bore of a pilot master cylinder, 1/2" maybe?

[masterfabr]

Originally Posted by Bugpac

you could mount a larger wilwood cylinder down below, and run a slave cylinder off the pilot master to operate the larger cylinder, be like power brakes for ya....

good idea

[grant_wt]

If your lever is going all the way to the steering wheel you need to get a larger bore master. I have also heard that stainless lines can help firm up your brakes, but I have a hard time believing since you still have rubber lines which have to flex more than steel.

If your lever feels hard, but nothing happens you need to go to a smaller bore master to increase your mechanical advantage.

I also like bugpacs idea. My dad did something similar with a 2.8 v6 powered buggy he had. Stock master just gave you foot cramps you had to push it so hard, so he ran a levered push rod to a power master that sat back near the engine. You could do the same thing with a cable or a hydraulic system in between. Firefly's and similar small cars have pretty small vacuum pots that can be hidden fairly well.

Grant