Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Heater Control Valve: Service and Repair

Coolant Bypass Valve Replacement

Tools Required
- J 38185 Hose Clamp Pliers

Removal Procedure
1. Partially drain the engine coolant.







2. Using the J 38185 slide the hose clamp (2) back on the coolant bypass inlet hose.
3. Disconnect the coolant bypass inlet hose (1).
4. Using the J 38185 slide the hose clamp back on the coolant bypass outlet hose.







5. Using the J 38185 slide the hose clamp (2) back on the coolant bypass outlet hose.
6. Disconnect the coolant bypass outlet hose.
7. Disconnect the vacuum hose (1).







8. Using the J 38185 slide the hose clamp (1) back on the coolant bypass hose.
9. Disconnect the coolant bypass hose.







10. Remove the bolt (1) that retains the valve to the coolant bypass valve assembly.
11. Remove the coolant bypass valve.




Installation Procedure
1. Install the heater hoses to the coolant bypass valve.







Notice: Refer to Fastener Notice in Service Precautions.
Fastener Notice


2. Install the coolant bypass valve bolt (1).
Tighten the bolt to 6.5 Nm (58 inch lbs.).







3. Position the coolant bypass hose (2) into the original position.
4. Using the J 38185 slide the hose clamp (1) back into the original position.
5. Install the outlet bypass hose to the coolant bypass valve.







6. Use the J 38185 to slide the hose clamp (2) into there original position.
7. Connect the vacuum hose (1).
8. Install the bypass inlet hose (1) to the coolant bypass valve.
9. Use the J 38185 to slide the hose clamp (2) into their original position.
10. Refill the cooling system.