Brakes; Aerodynamics Considerations - BOMBARDIER 1996 Ski-doo MX Z440 Handbook

Section 03
CHASSIS PREPARATION
, A06DOJS
1. Hold bleeder adaptor while opening bleeder
2. Clear hose to catch used brake fluid
Pump a few time brake lever and while holding brade lever depressed, open bleeder and check for
air to escape.
Repeat with the same bleeder until no air appears in hose.
Proceed the same way with the right side bleeder.

BRAKES

To achieve maximum top speed and proper brake functioning, it is important to make sure the
brake disc is loose on the countershaft to allow the disc to float and remain centered between the
brake pads. The shaft should be Iubed to maintain the floating disc.
If extreme brake use is anticipated, use 3 inch diameter dryer hose (or equivalent) to route outside
air directly from the hood vents to the brake area.
Both the Wilwood and Brembo hydraulic brake systems use DOT 4 brake fluid. For conditions
where extreme brake heat is generated, DOT 5 fluid can be used. DOT 5 has a higher boiling point
but it is more susceptible to moisture intrusion and should be changed on a regular basis. DOT 5
should not used for long, multi-day cross country racing where maintenance is minimal.
If the brakes become "spongy", the system should be bled to remove any air bubbles. If the brake
fluid is dark and/or cloudy, flush the complete system and refill with fresh brake fluid.
When refilling the injection oil container be careful not to overfill as excess oil can drop onto the
brake disc and impregnate the brake pads. If this happens the brake pads should be replaced to
ensure maximum braking performance.
AERODYNAMIC CONSIDERATIONS
Yes, aerodynamics are an important consideration in snowmobile design. The horsepower re-
quired to overcome aerodynamic drag increases according to the cube of the velocity. At speeds
under 64 km / h (40 MPH), the aerodynamic considerations are not great, but when you approach
the 160 km/ h (100 MPH) mark, simply how you sit on the snowmobile can mean 6.4 km / h (4 MPH)
in top speed.
03-68
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