Does the 6 cyl engine have a bleed valve to purge air when the coolant is replaced? My buddy can't find the owner's manual and just did a "drain 'n fill" with fresh Prestone (All Makes All Models).
'06 Trailblazer - coolant bleed valve?
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You'll probably be OK.
Keep an eye on the recovery tank for several days, after a few hot/cold cycles.
Keep an eye on the recovery tank for several days, after a few hot/cold cycles.
There's no bleed that I recall on the Atlas/Vortec 4.2L, nor do I think you'd need one. The water pump is mounted lower than the top hose, overflow tank, etc. You can see the water pump to the left of the alternator:
Joel
Joel
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What a Frankenstein of an engine!
I'd be more concerned about the Prestone all makes/models than the bleed valve.
But there is not bleed valve. Here is GM's procedure:
xTooltipElement
Service Information
2006 Chevrolet TrailBlazer - 2WD | Envoy, Rainier, TrailBlazer, Ascender (VIN S/T) Service Manual | Engine | Engine Cooling | Repair Instructions | Document ID: 1361893
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Cooling System Draining and Filling (LL8)
Tools Required
• J 38185 Hose Clamp Pliers
• J 26568 Coolant and Battery Fluid Tester
Draining Procedure
Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
Important: Draining the cooling system with the pressure cap installed will syphon the coolant from the overflow tank.
Park the vehicle on a level surface.
Allow the engine to cool.
Remove the radiator cap.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
Place a drain pan under the lower radiator hose connection at the bottom of the radiator.
Using J 38185 slide the hose clamp back on the hose.
Slowly remove the outlet (lower) radiator hose and drain the coolant into the drain pan.
Inspect the engine coolant for the following conditions:
• Discolored appearance--Follow the flush procedure. Refer to Flushing .
• Normal in appearance--Follow the filling procedure.
• If a complete block drain is required, remove the plug located on the LH side of the block.
Coolant Filling Procedure
Notice: The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.
If a complete block drain was required, install the plug.
Install the outlet (lower) radiator hose.
Using J 38185 slide the clamp into the original position.
Lower the vehicle.
Important: Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system through the top of the radiator until full. Refer to Approximate Fluid Capacities .
Remove coolant recovery reservoir cap.
Fill the coolant recovery reservoir with the remaining coolant.
Install coolant recovery reservoir cap.
Install the radiator cap.
Start the engine.
Run the engine at 1,000-3,000 RPM in 30 second intervals until the engine reaches normal operating temperature.
Allow the engine to idle for 3 minutes.
Shut the engine OFF.
Allow the engine to cool.
Top off the coolant recovery reservoir as necessary.
Rinse away any excess coolant from the engine and the engine compartment.
Inspect the cooling system for leaks.
Inspect the concentration of the engine coolant using J 26568 .
© 2009 General Motors Corporation. All rights reserved.
But there is not bleed valve. Here is GM's procedure:
xTooltipElement
Service Information
2006 Chevrolet TrailBlazer - 2WD | Envoy, Rainier, TrailBlazer, Ascender (VIN S/T) Service Manual | Engine | Engine Cooling | Repair Instructions | Document ID: 1361893
--------------------------------------------------------------------------------
Cooling System Draining and Filling (LL8)
Tools Required
• J 38185 Hose Clamp Pliers
• J 26568 Coolant and Battery Fluid Tester
Draining Procedure
Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
Important: Draining the cooling system with the pressure cap installed will syphon the coolant from the overflow tank.
Park the vehicle on a level surface.
Allow the engine to cool.
Remove the radiator cap.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
Place a drain pan under the lower radiator hose connection at the bottom of the radiator.
Using J 38185 slide the hose clamp back on the hose.
Slowly remove the outlet (lower) radiator hose and drain the coolant into the drain pan.
Inspect the engine coolant for the following conditions:
• Discolored appearance--Follow the flush procedure. Refer to Flushing .
• Normal in appearance--Follow the filling procedure.
• If a complete block drain is required, remove the plug located on the LH side of the block.
Coolant Filling Procedure
Notice: The procedure below must be followed. Improper coolant level could result in a low or high coolant level condition, causing engine damage.
If a complete block drain was required, install the plug.
Install the outlet (lower) radiator hose.
Using J 38185 slide the clamp into the original position.
Lower the vehicle.
Important: Slowly add a mixture of 50/50 DEX-COOL antifreeze and deionized water to the cooling system through the top of the radiator until full. Refer to Approximate Fluid Capacities .
Remove coolant recovery reservoir cap.
Fill the coolant recovery reservoir with the remaining coolant.
Install coolant recovery reservoir cap.
Install the radiator cap.
Start the engine.
Run the engine at 1,000-3,000 RPM in 30 second intervals until the engine reaches normal operating temperature.
Allow the engine to idle for 3 minutes.
Shut the engine OFF.
Allow the engine to cool.
Top off the coolant recovery reservoir as necessary.
Rinse away any excess coolant from the engine and the engine compartment.
Inspect the cooling system for leaks.
Inspect the concentration of the engine coolant using J 26568 .
© 2009 General Motors Corporation. All rights reserved.
Dexcool!!!
They still use that stuff?
They still use that stuff?
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