Honda K20C1 Operating Instructions Manual page 5

Engine Bleed Procedure
Please read the entire bleeding procedure in details before attempting to bleed a car.
During previous running, HPD has witnessed abnormally high water temperatures that
have been directly linked to poor bleeding of the cooling system. In an effort to reduce
instances of high water temperatures, teams shall follow the bleed procedure outlined
below.
Bleed procedure from an empty system:
1. Attach clear hoses to all bleed ports (LHS Radiator Fig.1, RHS Rad Fig.2, Oil cooler
Fig.3 and cylinder head port fig.6)
2. Position all clear lines in a position such that they are above the header tank. The
hoses need to be free of obstruction, open to atmosphere. It is recommended to use
clear hoses as it will be easier to witness the presence of bubbles.
3. Fill the cooling system with distilled water until no more air bubbles can be seen in
the clear bleed lines (~4 Gallons).
4. While filling up make sure that the water level is the same between the clear lines
and the water tank. The bleed line open ends will be slightly above the header tank.
5. Remove clear bleed lines. Ensure that the water level in the header tank is ~2in
below the bleed ports.
NOTE: As the clear lines are removed, a small quantity of air can be introduced.
Add water to the header tank to maintain the water level.
6. Connect two (2) full blead lines, one (1) from cylinder head port and one (1) from the
LHS radiator to the water header tank (do not overtorque).
7. Cap off the RHS radiator and the oil cooler bleed ports (do not overtorque)
8. Clean and dry any spilled water.
9. Start the engine and inspect for leaks. It is easier to detect leaks when the bleed
ports are dry and free of contaminants. Warm to engine to 70degC and always check
the water level at this temperature.
10. With the header tank cap off, monitor the water level on engine run-up, the water
level should be stable and should not have any air bubbles. Always monitor coolant
temperature on the dash while doing so. Do not exceed 90degC.
11. Inspect the cap seals for defects. Close the header tank ensuring that the cap is
closed tightly. It should have a positive feel. If the cap feels loose, replace
immediately. Check for leaks in water system once more.
This document is confidential and is supplied on express condition that it shall not be lent, copied, or
disclosed to any other person, or used for any other purpose without the written consent of Honda
Performance Development.