Tips for coolant fill?

[bigmoe]

I'm getting closer and closer to start up. Going to install my RND rad today and hook up hoses. I still have to pick up a steam hose. I read on here a long time ago some tips for filling it with coolant and getting trapped air out but I can't find it doing a search. I've heard some guys jack the front end up to help get air out. Any advice?

[Rickysnickers]

I have no experience with LS engines, but I can't imagine they are that much different than standard engines. I have always filled my engine with coolant, about 2"-3" from the top of the radiator fill. Run the engine w/o the radiator cap on it and let the engine come up to temp. This "burps" the engine, getting out all the air. After that's done then I just fill the rest of the way up and put the lid on.

[mongocanfly]

well they are a little different...remove the top rad hose from the radiator ,tie it up and fill the engine thru the hose...itll keeping purging air..keep filling till no more air comes out of the hose..then hook it back up and finish filling radiator..make sure the heater hose can bypass as well...jacking up front end does practically nothing

[prodjay10]

Fill through top radiator hose. Connect top hose to radiator and continue filling through radiator. Make sure the overflow tank also has coolant.

[bigmoe]

Thanks guys. Through the top hose it is. Just have to get some heavy 1/4" for the steam line. I have a u-shaped hose on the heater hose outlets for now.

[MySons68C20]

Fill through upper radiator hose as stated but keep the steam line off until it flows from where it connects to the radiator.
I just did this and it works great.

[LS short box]

Couple of things I've done with my LS swaps.
1. If your steam coolant line is connected to the radiator fill just below it to watch for flow.
2. I get them up to temp and then loosen the temp sensor on the left head just enough to get some coolant flow. Be careful that coolant will be hot. And don't over torque the sensor it will break. As me how I know.

Also depending on your radiator setup with the cap off when the thermostat is open you should see a strong flow of coolant coming out of the cooling tubes.
Watch your temp gauge and it's a good time to make sure your fan kicks in if you are running a electric fan

[First c10]

My father-in-law was a heavy equipment mechanic. He told me always drill a 1/8” hole in the thermostat so it will always have a little flow through the motor. And fill as the rest described. Above all work as long as you keep an eye on it.

[mongocanfly]

the thermostat on mine came with the small id hole in it

[ls1nova71]

I think all thermostats have a small hole in them. The problem is, if you rely on that, you're essentially filling the block through an 1/8" hole, it will eventually fill, but will take a very long time. Filling through the upper hose is the best way to fill a swap that doesnt have a factory surge tank.

[Rickysnickers]

Originally Posted by mongocanfly

well they are a little different...remove the top rad hose from the radiator ,tie it up and fill the engine thru the hose...itll keeping purging air..keep filling till no more air comes out of the hose..then hook it back up and finish filling radiator..make sure the heater hose can bypass as well...jacking up front end does practically nothing

Thank you for sharing that, so now I know as well. I wasn't trying to lead anybody astray.

[sweetk30]

https://www.lislecorp.com/specialty-...ree-funnel-606

any coolant job these days this is the GOLDEN TICKET . had mine so long i had to buy the update parts that now come in the kits .

fill up till no more goes in . keep funnel 1/3 full only as heated coolant will make it fill up on the first big open cycle .

when all done and happy pinch a big hose by hand and hold it . install plug in funnel . let go of hose . remove funnel kit and adapter and install cap for a 99% no spill job .

[mongocanfly]

shucks Ricky...aint nothing but a thang....the LS is bad to trap air for some reason...that's why we fill the engine thru the radiator hose...
and another thing is the loop hose on the heater hose inlet outlet...i was told not to cap off the heater hose fittings..at the minimum use a 180deg loop hose on them if your not running a heater core.. they say if you don't have flow around the thermostat , it wont open ,sometimes..like I said, some people havnt had any issues and some have..there have been a few on here that had overheating issues and its usually air in the block or heater hoses blocked off

[skyphix]

Originally Posted by ls1nova71

I think all thermostats have a small hole in them. The problem is, if you rely on that, you're essentially filling the block through an 1/8" hole, it will eventually fill, but will take a very long time. Filling through the upper hose is the best way to fill a swap that doesnt have a factory surge tank.

How about for those of us that DO have the factory (LS. 2006 Yukon) surge tank and radiator setup? I figure still fill through the top hose, then keep topping off the surge tank? The radiator is also bone dry (new radiator.)