ls1tech.fan

iTrader: (6)

How do I bleed the air after a coolant flush ?

I read that the throttle body line should be disconnected and then the radiator filled until coolant flows steadily from the throttle body line ?

Can I do this without running the car with cold coolant or does the coolant need to be hot and the engine running in order to have the thermostat open allowing flow to the throttle body ?

Please explain in detail.
Thanks

RFERG43

Per the GM factory Camaro manual: Fill the radiator to the top, run engine until the thermostat opens. Add coolant as necessary. Run until no air bubbles are observed. It does mention opening an air bleed **** on the radiator but mine doesn't have one. I did leave the steam vent tube disconnected and jacked the front of the car up a little when I filled mine. This was on an LS1/RX7 swap. Also turned the heater control on so the heater core got filled.

ls1tech.fan

iTrader: (6)

Took off the throttle body coolant line on the drivers side and started the car. The fluid started flowing out . . . after 15 seconds or so without seeing any air bursts, I hooked the line back and turned off the car. Never waited for the engine to warm up.
Am I fine ? Cold level in the resivoir was fine. Radiator was full.

waterbug1999

iTrader: (3)

Once it does get warm/normal temp, turn your heater on. That will get some air out of the heater core/ lines as well. Saw my radiator "burp" after I turned it on.

jkichline

iTrader: (1)

Let your car run until the temperature rises... If the temp seems regulate around 190° you should be fine. If the temp keeps rising, you'll need to get the air out. This happened to me when I filled mine and kept me up til 2 in the morning trying to figure it out . There should be bleeder screws near the highest point of your cooling system. Mine are on a hose coupler near the front on the passenger side (I think there are two). Open those until coolant comes out. Then you should be good. Although, I have an LT-1. I'm sure what the setup is on an LS-1.

ls1tech.fan

iTrader: (6)

No bleeder screws on the ls1.

Is bleeding the air really necessary when the radiator is drained from its drain plug and then refilled from the cap ?

jkichline

iTrader: (1)

Yes. It is necessary to bleed the air because your fill hole is NOT your highest point in the cooling system. If you could imagine filling a cup from the middle, there will be air left above the fill hole. If there is air in the system, you will not have water flow. Without coolant flowing through the engine... well, you know what happens... Since I don't have the LS-1 I can't give you the exact procedure. But I can tell you from experience.... Air in the system is a BAD thing. Do you have a Chilton or Haynes book? They should tell you exactly how to do it.

Rokko

iTrader: (2)

I did the same procedure with the addition of this:

Now start the car and let it warm up with the radiator cap off and the heater on. You'll see the coolant level drop off when the thermostat opens and closes. Add the coolant mix as needed.

Mine took around a half an hour before the level finally quit dropping after the thermostat quit cycling open and closed the first couple times after a cold start.

I checked mine a lot after, that just to be sure that the level was OK. It was every time.

We skipped this step on a buddies car and took off due to time restraints. Bad idea, we were about only 2/3's full. The temp shot up past red in a couple blocks.