Proheat X45–School Bus - Manual (Page 29)

Figure 3-13 Engine Heat or Supplemental Heat
OPTION A – Engine Heat or Supplemental Heat
Instructions for Options A and B
1. Remove the radiator cap to release the system pressure.
2. Drain the coolant system.
3. Plumb the system as per Figure 3-13 or Figure 3-15
4. Add engine coolant to the system as per the specific engine
manufacturer’s recommendations and re-install the radiator cap.
NOTE: Plumbing the PROHEAT through the dash fan is not recommended.
NOTE: On coolant systems where the return from the PROHEAT is plumbed to
the bottom of the main coolant supply line from the radiator to engine
pump, the return line must be moved to avoid loss of heat through the
radiator.
DASH HEATER
ENGINE
RETURN TO ENGINE
SUPPLY TO PROHEAT
Figure 3-14 Correct Return Line Plumbing
® ®
ENGINE ENGINE
SUPPLY TO PROHEAT
RETURN TO ENGINE
SUPPLY TO PROHEAT
RETURN TO ENGINE
WARNING
Opening the radiator cap when
the engine is hot may cause
serious injury.
3-8 PROHEAT INSTALLATION & SERVICE
3.4.2