Coolant noise inside cab, need help

[Old Blue]

I've got an issue going on with my '99 obs K1500. I recently replaced the radiator (after some stop leak didn't fix the leak). I let the truck run as I was filling the radiator, but it didn't take very long for the the bubbles to stop coming out, so I thought it purged all the air out. Now I get what sounds like water sloshing around under the dash on the passenger side. It only does it under acceleration. I'm not sure what's the best way to remedy this

 

[someotherguy]

Park the truck on an uphill incline like a steep driveway, engine at the high end. Run it with the cap off in an attempt to burp the system some more. If you don't have an incline then throw it up on some jack stands/ramps.

If that doesn't get it, you have a leak somewhere. Bet on it. May be so small you can't immediately see it, but it's there.

Richard

 

[RichLo]

Had that problem forever with a blazer, it took several times parked on a hill to finally get it out.

 

[Old Blue]

Thanks guys

 

[DerekTheGreat]

Hah, I've got the same issue now that I back flushed my heater core and the entire dham system. I like it, the sound of powah! /s

Welp, now I know how to fix the issue, thanks fellas

 

[Nathaniel2g]

Make sure you have your heater on fully when you're bleeding it. Should help get the air and the coolant stuck in your heater out.

 

[90halfton]

What these guys said. On a separate note, leak stop usually just plugs up all the passages except for the leak you were trying to "bubble gum" shut. Not good stuff at all.
When I fill coolant on a motor/radiator that has been drained out I usually pull the temp sensor out of the intake manifold so air can escape naturally out the top. Just an idea. Most newer vehicles have a small valve up high somewhere to open that will allow that to happen.

 

[Nathaniel2g]

What these guys said. On a separate note, leak stop usually just plugs up all the passages except for the leak you were trying to "bubble gum" shut. Not good stuff at all.
When I fill coolant on a motor/radiator that has been drained out I usually pull the temp sensor out of the intake manifold so air can escape naturally out the top. Just an idea. Most newer vehicles have a small valve up high somewhere to open that will allow that to happen.

As far as I'm aware the radiator fill cap or coolant bottle fill on pressurized systems should always be the highest point in the system. Theoretically all air should be pushed there.

 

[DerekTheGreat]

Funny that a pocket of air gets trapped in the heater core.

 

[90halfton]

As far as I'm aware the radiator fill cap or coolant bottle fill on pressurized systems should always be the highest point in the system. Theoretically all air should be pushed there.

If the thermostat is closed air will be trapped in the intake manifold. Especially if you have scrapped the quick disconnect hose in favor of a male adapter, in which case the heater hose travels higher than the radiator cap (due to the loop the hose now has to make). Coolant will fill the heater core, radiator, water pump etc, but trap air in the intake manifold and top heater hose. Have done it a million times without pulling the sensor. Just gets all the air out more quickly and efficiently.