GMC 12632948 Thermostat,Engine Coolant

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Before condemning the thermostat, it is important to check the coolant level, drivebelt tension, and temperature gauge or light operation. If the engine takes a long time to warm up, it is likely that the thermostat is stuck open and should be replaced. On the other hand, if the engine runs too hot and the upper radiator hose is not hot, it indicates that the thermostat is stuck closed and needs to be replaced. However, if the upper radiator hose is hot, it means that the coolant is circulating and the thermostat is open. It is worth noting that if an engine has been overheated, there may be damage such as leaking head gaskets, scuffed pistons, and warped or cracked heads. To remove the thermostat, start by disconnecting the negative cable from the battery and draining about two quarts of coolant from the cooling system. Then, remove the air cleaner assembly and detach the upper radiator hose from the thermostat housing cover fitting. Remove the bolts and detach the thermostat housing cover and gasket. Lift out the thermostat, ensuring to note its installation orientation. Clean the gasket mating surfaces with a gasket scraper and lacquer thinner or acetone to remove any old gasket material and sealant. To install the new thermostat, apply a thin layer of RTV sealant to the gasket mating surfaces of the housing and cover. Install the new thermostat in the housing, making sure the correct end faces up. Position a new gasket on the housing and align the bolt holes. Carefully position the cover on the housing and tighten the bolts to the specified torque. Reattach the radiator hose to the cover fitting and tighten the hose clamp. It is recommended to check and replace all cooling system hoses and clamps at this time. Finally, refill the system, run the engine, and carefully check for any leaks.

Remove the thermostat.

It is important not to drive the vehicle without a thermostat as it will cause the computer to stay in open loop, resulting in decreased emissions and fuel economy. Before condemning the thermostat, check the coolant level, drivebelt tension, and temperature gauge (or light) operation. If the engine takes a long time to warm up, the thermostat is likely stuck open and should be replaced. If the engine runs hot and the upper radiator hose isn't hot, the thermostat is probably stuck shut and should be replaced. If the upper radiator hose is hot, it indicates that the coolant is circulating and the thermostat is open. In cases where the engine has been overheated, there may be damage such as leaking head gaskets, scuffed pistons, and warped or cracked cylinder heads. To replace the thermostat, drain about three quarts of coolant from the radiator until the level is below the thermostat housing. Disconnect the upper radiator hose from the thermostat housing cover, remove the nuts/bolts, and lift off the cover. It may be necessary to move the belt tensioner bracket aside and tap the cover with a soft-face hammer to break the gasket seal. Take note of how the thermostat is installed, then lift it out. Use a scraper or putty knife to remove any old gasket material and sealant from the mating surfaces, being careful not to let any fall into the coolant passages. Clean the mating surfaces with lacquer thinner or acetone. Apply a thin layer of ATV sealant to the gasket mating surfaces of the housing and cover, and install the new thermostat in the engine with the correct end facing up. Position a new gasket on the housing, ensuring the holes line up with the bolt holes. Carefully position the cover on the housing and install the bolts, tightening them to the specified torque without overtightening to avoid distortion. Reattach the radiator hose to the cover and tighten the clamp. It is recommended to check and replace hoses and clamps at this time. Refill the system, then run the engine and carefully check for any leaks.

You can check the temperature of the radiator hose that leads from the thermostat to the radiator. If the hose is not hot, but the engine is, it is likely that the thermostat is stuck closed and should be replaced.

Ensure the correct end faces out, with the spring directed toward the engine.

Begin by draining about three quarts of coolant from the radiator until the level is below the thermostat housing. Disconnect the upper radiator hose from the thermostat housing cover. Remove the nuts/bolts holding the cover and lift it off. It may be necessary to move the belt tensioner bracket aside and tap the cover with a soft-face hammer to break the gasket seal. Note the orientation of the old thermostat and then lift it out. Use a scraper or putty knife to remove any old gasket material and sealant from the mating surfaces, being careful not to let any fall into the coolant passages. Clean the mating surfaces with lacquer thinner or acetone. Apply a thin layer of ATV sealant to the gasket mating surfaces of the housing and cover. Install the new thermostat in the engine with the correct end facing up. Position a new gasket on the housing, ensuring the holes line up with the bolt holes. Carefully position the cover on the housing and install the bolts, tightening them to the specified torque without overtightening to avoid distortion. Reattach the radiator hose to the cover and tighten the clamp. It is recommended to check and replace hoses and clamps at this time. Refill the system with coolant. Run the engine and carefully check for any coolant leaks.

Use a scraper or putty knife to remove any old gasket material and sealant from the mating surfaces.

It is important to check the coolant level, drivebelt tension, and temperature gauge (or light) operation.

If the engine runs hot, the thermostat is probably stuck closed, preventing the coolant inside the engine from escaping to the radiator.

You can check the temperature of the radiator hose that leads from the thermostat to the radiator. If the hose is not hot, but the engine is, it is likely that the thermostat is stuck closed and should be replaced.

Remove the thermostat.

This thermostat opens at 180 degrees