Heater Bleeding Instructions - Blue Bird Micro Bird Operator's Manual

MICRO - BIRD

HEATER BLEEDING INSTRUCTIONS

The following procedure must be followed to insure adequate
heater bleeding. During the bleeding process, it will be necessary
to remove the radiator cap and refill cooling system several times
to insure adequate coolant is available to replace purged air and
coolant lost when bleeding.
CAUTION: Extreme care must be used when removing
radiator cap. As coolant becomes hot, pressure is built up in the
cooling system. Rapid venting and/or removal of radiator cap
will cause coolant to boil up and spray out and can result in
serious burns. Slowly vent of pressure before removing radia-
tor cap.
Procedure
1. With engine off, shut engine heater return gate valve or clamp
closed heater return hose as close to engine as possible. Close
temperature control on dash by turning clockwise.
2. Fill cooling system completely, including recovery tank with
coolant and run engine for a few minutes to bleed air from
cylinder block and heads.
3. Open heater hose supply line by turning temperature control
on dash counterclockwise. Turn on heater water pump if
equipped.
4. Using a suitable container to catch the coolant, run the engine
between 2,000 and 3,000 RPM, loosen bleeder valve located in
heater hose return line. Bleed air and coolant through bleeder
valve until air is eliminated from heater system. (Stop bleed-
ing when condones stream of coolant comes from bleeder
valve.)
Note: It will be necessary every few moments to refill the
radiator.
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