A. Install Bypass Valve

1. Remove the heated air tube (Figure 1).

2. Slowly remove the coolant bottle pressure cap (when cold) to relieve system pressure. Discard the cap.

WARNING:
Do not loosen the coolant bottle pressure cap, hoses or bleed screws while the coolant is still hot and the system is pressurized. Hot engine coolant can cause severe burns. Allow the system to cool down before starting the service procedure.

3. Disconnect the engine to coolant bottle hose from the engine (Figure 1). Drain the coolant into a container and then disconnect the hose from the coolant bottle.

4. Disconnect the engine to heater core hose from the engine (Figure 1). Drain the coolant into a container.

5. Disconnect the heater core to coolant bottle hose and small upper hose from the coolant bottle (Figure 1).

6. Release the coolant bottle retaining strap. Remove the coolant bottle from the bracket and set it aside (Figure 1).

7. Disconnect the two hoses from the heater core (Figure 1). Discard the hoses and clamps.





8. For Vehicles Equipped with an Automatic Transmission Only:
Remove the speedometer cable from the plastic retaining clip (Figure 2).

9. For Vehicles Equipped with an Automatic Transmission Only:
Secure the speedometer cable to the existing hole located approximately 2" (50 mm) below the plastic retaining clip (Figure 2) with one of the provided tie straps.





10. Install the provided protective hose over the two (2) fuel lines as shown in Figure 3.

11. Secure the protective hose with two of the provided tie straps, place one near the top and one near the bottom of the hose.

12. Slide the hose down until it rests on the clamps at the base of the fuel lines.





13. Install the short end of the two (2) provided 900 formed heater core hoses on to the heater core nipples (Figure 4).

NOTE:
Both heater core hoses have the same hose diameter on both ends. The hose with the air bleed valve should be connected to the forward heater core nipple.

14. Install the supplied bypass valve on the two heater core hoses installed above (Figure 4). Tighten all four hose clamps securely.

NOTE:
The vacuum motor on the bypass valve will be oriented in the UP position when correctly installed.

15. Reinstall the coolant bottle. Secure the bottle with the rubber retaining strap.

NOTE:
On 1988 model year vehicles, ensure that the vacuum hose on the vacuum canister, located behind the coolant bottle, has not been dislodged during bypass valve installation.





16. Install the bypass valve to coolant bottle hose (Figure 5). Use one of the large hose clamps on the coolant bottle end.

17. Install the coolant bottle to engine hose (Figure 5). Use the other large hose clamp on the coolant bottle end.

18. Install the engine to bypass valve hose (Figure 5).

19. Secure the brass part of the bypass valve to the plastic trough with one of the provided tie straps (Figure 5) and then tighten all hose clamps securely.

IMPORTANT:
Make sure that there is sufficient clearance between the protective covering on the fuel hoses and the bypass valve to allow proper operation of the valve (Figure 5).





20. Locate the vacuum hose that connects the throttle body housing to the charcoal canister. Cut that hose 7-1/2 from the throttle body housing (Figure 6).





21. Route the bypass valve vacuum hose along the plastic hose trough assembly at the rear of the engine compartment (Figure 7).

22. Install the plastic vacuum tee at the end of the bypass valve vacuum hose between the cut ends of the throttle body vacuum hose (Figure 7).

23. Secure the vacuum hose to the plastic trough assembly using three (3) of the supplied tie straps (Figure 7).

24. Secure the vacuum hose to the throttle cable using one (1) of the supplied tie straps (Figure 7).

25. Reinstall the heated air tube.