Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET1999ASTRO VAN 2WD V6-4.3L VIN WREPAIR AND DIAGNOSISHEATING AND AIR CONDITIONINGHEATER CONTROL VALVESERVICE AND REPAIRSTANDARD
1999 Chevrolet Astro Van 2WD V6-4.3L VIN W
Standard
1999 Chevrolet Astro Van 2WD V6-4.3L VIN WSECTION Standard
Hot Water Bypass Valve Replacement
REMOVAL PROCEDURE
1. Remove the air cleaner.
2. Drain the engine coolant. Refer to Draining and Filling Cooling System in Engine Cooling.
3. Remove the hose clamps from the outlet pipe (6) and from the inlet pipe (5).
4. Remove the heater inlet pipe (5) and the outlet pipe (6) from the bypass valves (4).
5. Remove the bolts (3) that retain the valves (4) to the heater assembly.
6. Remove the bypass valves (4) from the heater assembly.
INSTALLATION PROCEDURE
1. Install the bypass valves (4) to the heater assembly.
NOTE: Refer to Fastener Notice in Service Precautions.
2. Install the bolts (3) that retain the valves (4) to the heater assembly.
Tighten
Tighten the bolts that retain the valves to 4 N.m (35 lb in).
3. Install the heater inlet pipe (5) and the outlet pipe (6) to the bypass valves.
4. Install the hose clamps.
Tighten
Tighten the hose clamps to 4 N.m (35 lb in).
5. Fill the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling.
6. Ensure that no leaks exist in the cooling system.
7. Install the air cleaner.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.