Coolant bleeder valve
Thread Starter
Melting Slicks
Joined: Jun 2010
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From: Clinton MO
Coolant bleeder valve
I need to get the air out of my coolant system and i have no idea where the valve is or what it looks like. pics would be appreciated. car is a 86 with the L98 out of a 91
Drifting
Joined: Aug 2006
Posts: 1,624
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From: Canandaigua New York
Start the engine and run it up to temperature to make sure the thermostat opens.
With the engine running, remove the radiator cap and fill the radiator up just over the top of the fill tube. (look down inside of the outlet and you'll see the tube)
Make sure you use a rag and remove the cap slowly so it doesn't spray out.
Once it's full to the right level, replace the cap.
Make sure your overflow tank is filled to the proper level and you should be fine.
Just did this on my 87 after installing a thermostat.
With the engine running, remove the radiator cap and fill the radiator up just over the top of the fill tube. (look down inside of the outlet and you'll see the tube)
Make sure you use a rag and remove the cap slowly so it doesn't spray out.
Once it's full to the right level, replace the cap.
Make sure your overflow tank is filled to the proper level and you should be fine.
Just did this on my 87 after installing a thermostat.
Last edited by Keystring; Oct 6, 2010 at 07:11 AM.
Thread Starter
Melting Slicks
Joined: Jun 2010
Posts: 3,316
Likes: 0
From: Clinton MO
Start the engine and run it up to temperature to make sure the thermostat opens.
With the engine running, remove the radiator cap and fill the radiator up just over the top of the fill tube. (look down inside of the outlet and you'll see the tube)
Make sure you use a rag and remove the cap slowly so it doesn't spray out.
Once it's full to the right level, replace the cap.
Make sure your overflow tank is filled to the proper level and you should be fine.
Just did this on my 87 after installing a thermostat.
With the engine running, remove the radiator cap and fill the radiator up just over the top of the fill tube. (look down inside of the outlet and you'll see the tube)
Make sure you use a rag and remove the cap slowly so it doesn't spray out.
Once it's full to the right level, replace the cap.
Make sure your overflow tank is filled to the proper level and you should be fine.
Just did this on my 87 after installing a thermostat.
Drifting
Joined: Aug 2006
Posts: 1,624
Likes: 2
From: Canandaigua New York
Don't go by the feel of the cap temperature.
Feel the upper hose and make sure it's hot (touch it quick)
If it's not, then your thermostat hasn't opened yet.
225 deg should have been plenty hot enough to open it though since the stat is rated at 195.
Racer
Joined: Jul 2010
Posts: 308
Likes: 2
From: Kansas City MO
I would NOT recommend having the cap fully on when doing it - the buildup of pressure can be dangerous when released as hot coolant may spray - I like to put the cap on "one click" - the position where the cap is on but it's not "down" and can't really create pressure. Then start the engine, run it until hot and pull the cap, add coolant when it burps. Also - sometimes helps to run the heater in case there is air trapped in there too. The engine temp will keep spiking and then coming back down repeatedly until all the air is out of the system - you'll need to keep topping off the coolant until all the air is out.
Next time you replace the thermostat drill a tiny hole in the fixed portion of the thermostat - a small hole (like 1/16") will allow air to pass and burp it out quickly but not flow too much coolant to keep the engine from warming up in the winter.
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From: Fort Knox, KY
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Originally Posted by TheRenegade
so i should only have to do this once right? cuz i drove it the mile from my barracks to work and the sensor was reading 225* but the cap was still cool to the touch
Anytime you completely purge the system of coolant (i.e. water pump swap) and re-fill, you should keep an eye on your coolant level for a day or two after you refill.
I opened the bleed valve on my LT1 last Saturday after changing the WP and had to tap it off slightly on Sunday. The engine should be completely cool when you check it. It takes approximately two and 3/4 gallons of coolant.
so i should only have to do this once right? cuz i drove it the mile from my barracks to work and the sensor was reading 225* but the cap was still cool to the touch
Anytime you completely purge the system of coolant (i.e. water pump swap) and re-fill, you should keep an eye on your coolant level for a day or two after you refill.
I opened the bleed valve on my LT1 last Saturday after changing the WP and had to tap it off slightly on Sunday. The engine should be completely cool when you check it. It takes approximately two and 3/4 gallons of coolant.
Drifting
Joined: Aug 2006
Posts: 1,624
Likes: 2
From: Canandaigua New York
As stated before. He doesn't have a bleeder valve.
His 86 is the same as my 87.
Even if you completely drain the cooling system and flush it, you would still refill it the same
way I stated earlier.
The thermostat 'bubble' has nothing to do with how the thermostat opens.
The thermo 'spring' does, and that is what is in contact with the coolant.
As long as the water pump has coolant flowing through it, any air bubble will be displaced by the pressurized coolant and your thermostat will still open.
Once it opens, you add coolant, as it's running, and any air in the system will purge itself.
If you're not getting heat, at an idle, then you don't have enough coolant in the system.
And if you really feel it's necessary, you can loosen the radiator cap to 'bleed' air out. It would work the exact same way as a bleeder valve.
In all the cars I've ever owned, I've never had any problem with the coolant system by doing it the way I've stated.
His 86 is the same as my 87.
Even if you completely drain the cooling system and flush it, you would still refill it the same
way I stated earlier.
The thermostat 'bubble' has nothing to do with how the thermostat opens.
The thermo 'spring' does, and that is what is in contact with the coolant.
As long as the water pump has coolant flowing through it, any air bubble will be displaced by the pressurized coolant and your thermostat will still open.
Once it opens, you add coolant, as it's running, and any air in the system will purge itself.
If you're not getting heat, at an idle, then you don't have enough coolant in the system.
And if you really feel it's necessary, you can loosen the radiator cap to 'bleed' air out. It would work the exact same way as a bleeder valve.
In all the cars I've ever owned, I've never had any problem with the coolant system by doing it the way I've stated.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
[QUOTE=Keystring;1575540961]As stated before. He doesn't have a bleeder valve.His 86 is the same as my 87. QUOTE]
Not only that but it seems that many forget about the 2nd part of the recommended "burp" procedure: That the coolant by-pass hole behind the passenger side leg of the water pump be plugged.
Most everyone writes about drilling holes - the sizes and number of holes differ from poster to poster - but none mention plugging the by-pass hole. Guess there's too much work involved in doing that as the reason it isn't mentioned.
TPiS says BLOCK IT. They also recommend to drill different size holes defending on the season. Smaller for winter months and larger for the hot weather.
Jake
Not only that but it seems that many forget about the 2nd part of the recommended "burp" procedure: That the coolant by-pass hole behind the passenger side leg of the water pump be plugged.
Most everyone writes about drilling holes - the sizes and number of holes differ from poster to poster - but none mention plugging the by-pass hole. Guess there's too much work involved in doing that as the reason it isn't mentioned.
TPiS says BLOCK IT. They also recommend to drill different size holes defending on the season. Smaller for winter months and larger for the hot weather.
Jake
Thread Starter
Melting Slicks
Joined: Jun 2010
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From: Clinton MO
Heater core has already been bypassed by previous owner and to the other posters, the upper radiator hose is cool to the touch, there is no pressure in the system and the lower hose is barely warm to the touch. one of my buddies says its either a blockage somewhere or possibly a messed up temeprature sensor sending unit
Last edited by TheRenegade; Oct 7, 2010 at 12:39 AM.
Drifting
Joined: Aug 2006
Posts: 1,624
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From: Canandaigua New York
Heater core has already been bypassed by previous owner and to the other posters, the upper radiator hose is cool to the touch, there is no pressure in the system and the lower hose is barely warm to the touch. one of my buddies says its either a blockage somewhere or possibly a messed up temeprature sensor sending unit
Since you have no pressure, then my guess would be no thermostat.
When I got my 87 I asked the PO if the heat worked and he said 'yes'.
Problem was, the heat only worked when I stepped on the gas and the engine temperature only rose to 140 max, according to the gauge.
Upper hose always ran cooler than the lower as well.
I went and bought a 180 deg thermostat and installed it. Temps went to 180 and the heat worked fine afterwords. Also both hoses were pretty hot to the touch.
I'd check to make sure you have a thermostat installed.
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From: Fort Knox, KY
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Also, don't forget to close the radiator pitcock before re-filling with coolant. I almost did the dummy move last weekend while refilling my LT1.
