Thermostat replacement instruction on a 1995 Volvo 850 T-5
If your car is not warming up properly you likely need to replace the thermostat. When you start a cold car, it is best to drive it gently until it warms up. If it takes longer than 5 minutes or 3 miles to warm up you likely have a bad thermostat. It's the cheapest link in the chain. It can have a bad spring or a broken bracket in it, either way, if you decide to replace it, use the instructions below. Should take about 30 minutes.
Tools / Equipment Needed:
| Thermostat | Drip Pan (to catch drained antifreeze) |
| T-20 Torque Bit | Torque Bit Driver |
| T-40 Torque Bit | 1/4" Torque Bit Socket Adapter |
| 3/8" to 1/4" Socket Adapter | 3/8" Socket Wrench |
| Gloves | Pliers |
| Rags | Speed Wrench |
- Allow the car to cool off.
- Open the hood and drain some anti-freeze from the cooling system. I did not do this, I just put the drip pan under the car near the passenger side front tire and let whatever fluid loss occurred to drain into the pan.
- Disconnect the coolant reservoir overfill line from the thermostat
housing.
NOTE: Get the other thermostat ready to install. - If you want, you can remove the radiator hose, I left mine connected.
- Remove the two torque screws that hold the thermostat housing in place.
- Once you have the screws removed, you can work the housing off. You lift the rear end up then slide it towards the radiator.
- Remove the old thermostat. Be careful not to drop any pieces of the old thermostat into the engine.
- Clean off the housing and the part of the motor it mounts on.
- Install the new thermostat with the seal that came with it. It is NOT necessary to put any kind of sealant on the housing.
- Install the housing.
- Connect the water hoses.
- Re-fill the coolant system.
- Wash down any coolant that leaked into the engine compartment.
- Start and run the car for a few minutes and re-check the coolant system.
- It would be a good idea to check the coolant level a few times to make sure you got it filled properly and that you don't have any leaks.
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End of instructions.