Some thoughts on brakes and bleeding:
- dual master cylinder assemblies are designed to apply equal pressure (via the balance bar) to front and rear calipers. This configuration only works if it is adjusted properly, and has regular maintainance. Trying to drive a car fast with incorrect front/rear balance is always exciting, and will sometimes get you extra TV time......occasionally even the 11 o'clock news.......
Replacing a dual master assy. with a single is a large step backwards.....
- when changing caliper / piston size, it is necessary to change master cylinder size at the same time - you must keep the same master piston - to - caliper piston ratio. Obviously, if you change from a 2 piston caliper to a 4 piston caliper, some calculations need to be done.....(Tilton's website has formulas)
- a larger master cylinder piston will pump more fluid, therefore giving a firmer pedal/shorter stroke. A smaller one just the opposite. If a driver likes to modulate braking by pressure, he will like a "rock hard pedal" with little travel, but if a driver prefers to modulate braking by travel, then he will like a softer pedal.
- Tilton makes a neat bleeding kit, containing 2 plastic bleed bottles with attaching cables, tubing, etc.....
- bleeding procedure:
> pump pedal 3-4 times, (not fast) then hold pressure (person in car says "hold")
> both people at calipers open bleed screws
> when pedal bottoms, person in car says "down"
> both people at calipers close bleed screws, and say "closed"
> pump again, repeat.....
- when bleeding a dual system, whether it is a "race" system with dual masters and a balance bar, or a "street" system with a dual piston master, it is necessary to bleed a front and a rear at the same time. If the calipers have an inner and outer bleed, do the inside first, then the outside.
- be very cautious when using a vacuum bleeder, as too much vacuum can draw air past caliper seals...
- when tightening bleed screws, use a torque wrench, as 10-15 inch pounds is usually sufficient
- clean all fluid from bleeder and caliper body, otherwise it will attract dust and grunge, jamming threads, and plugging bleeders, etc...etc...
- for competition, use a good 600 degree fluid - AP, Motul, Wilwood, etc. Also, use a fresh bottle. Brake fluid has a severe inclination to absorb water - a bottle opened and sitting for a couple of weeks(even closed tightly) may have absorbed enough water from the atmosphere to become useless.
Threaded Mode
