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Bleeding air from coolant system

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Old Apr 9, 2008 | 03:40 PM
  #1  
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Default Bleeding air from coolant system

Does any one know where I can find the procedure for bleeding air from the coolant system? I want to know before I change the thermostat.

Thanks,
The Big Dog
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Old Apr 9, 2008 | 03:58 PM
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Draining and Filling Cooling System

Caution
With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.

Important
If the procedure below is not followed a low or high coolant level condition and/or vehicle damage could result.


1) Park the vehicle on a level surface.
2) Remove the surge tank cap:
3)Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
4) Place a drain pan under the drain plug.
5) Open the radiator drain plug .
6) Allow the cooling system to drain completely.
7) Inspect the engine coolant for the following:
Discolored -- follow the flush procedure below.
Normal in appearance -- continue with the next step.

Notice
When adding coolant, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner-at 50 000 km (30,000 mi) or 24 months.

Notice
Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


8) Close the radiator drain plug. Tighten.
Tighten the radiator drain plug to 2 N•m (18 lb in).

9) Fill the cooling system through the surge tank.
10) Fill the cooling system with a 50/50 mixture of DEX-COOL® coolant and deionized water.
11) Start the engine.
12) Allow the engine to idle for 1 minute.
13) Install surge tank cap.
14) Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant temperature reaches 99°C (210°F).
15)Shut off the engine.
16) Remove the surge tank cap.
17) Start the engine.
18) Allow the engine to Idle for 1 minute. Fill the surge tank to 12.7 mm (0.5 in) above the COLD FULL mark on the surge tank.
19) Install the surge tank cap.
20) Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant reaches 99°C (210°F).
21) Shut off the engine.
22) Remove the surge tank cap.
23) Top off the coolant as necessary, 12.7 mm (0.5 in) above FULL COLD mark on the surge tank.
24) Rinse away any excess coolant from the engine and the engine compartment.
25) Inspect the concentration of the engine coolant.
26) Install the surge tank cap.
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Old Nov 3, 2017 | 12:08 PM
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How much air could possibly be in my cooling system? I've been bleeding it for almost 15 minutes and its still hissing out of the crossover lines from the heads...
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Old Nov 3, 2017 | 01:17 PM
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all I do is leave the reservoir cap off and let the car idle for a good 20-30 mins, never had an issue doing it that way
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Old Nov 3, 2017 | 01:37 PM
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I'm sucking air into my cooling system from somewhere...possibly my thermostat housing from when I changed my thermostat and didn't get the bolts tight enough?
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Old Nov 3, 2017 | 01:49 PM
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Originally Posted by Ironworker48okc
I'm sucking air into my cooling system from somewhere...possibly my thermostat housing from when I changed my thermostat and didn't get the bolts tight enough?
If the housing bolt are loose I'd suspect it would be leaking coolant rather then sucking in air.
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Old Nov 3, 2017 | 03:03 PM
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Was my thought as well sg Lou...here's the deal....when the car is idling and I have the crossover lines from head to head loose they never stop pushing air...I can kill the car and let it cool and completely fill everything with water while they are loose and it starts pushing water out after about 2 1/2 gallons....it runs at temp for about 20 minutes before starting to get hot again. Could that still be the surge cap? I have no clue about the hoses....will have to let the car cool and get back to you on that one.
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Old Nov 3, 2017 | 03:40 PM
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Also forgot to ask if it would still suck air from the top if the cap is left off? Because it still moves air regardless...my thoughts would have been that it wouldn't be pressurized so it would just cycle the water without the cap on like any other vehicle...but I'm quickly finding out how temperamental these damn cars are! She has definitely earned her name "Agnus."
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