Recently obtained an 04 Ranger in pretty good shape, just doing routine work on it to bring it back to life and I figured I'd do the coolant today.

It wasn't too dirty but I figured I'd change it anyways so I drained the radiator and pumped out the fluid from the reservoir. I filled up the reservoir with water, about a gallon, and the engine sucked it up just fine, then it stopped after the first gallon. I ran the truck for a good 15-20 minutes, trying to burp the hoses by squeezing them and revving the engine a bit, but the coolant level is just not going down. I only have maybe 1.1 gallons in the truck now but it calls for 2.55.


Is it just random coolant that was leftover in the heater core and engine or is it air? If it is air, anyone have any suggestions on how to bleed it?

 

Engine off and cold
Loosen and remove a heater hose, engine side of by-pass valve if so equipped.
Fill engine via rad cap opening until coolant is coming out hose/fitting
Reattach hose and tighten.

Start engine and turn heater to hot, defrost OFF, fan doesn't need to be on.

Let it idle with rad cap off, top up if level in rad drops, after engine runs for about 5 minutes coolant may start coming out of cap opening, put cap on.
Make sure overflow is at least 1/2 full.
Drive truck up and down a hill or two if available, this can help push air out of places it may be trapped.
Any air will end up at the top of the rad and will eventually be pushed out into overflow tank and bubble to the top, then when engine cools down coolant will be pulled back in via the second valve in the rad cap, the small center valve.

 

The 2.3 lacks a rad cap but I'll try elevating the rad tomorrow morning on my way to class. Gonna keep a few jugs of water in the cab just in case the level drops too much