Cooling clarification

[capt ford]

Recently purchased a low mileage 1992 Explorer Sport, to replace my venerable old (1988) Bronco II as a thrash and tow vehicle. It periodically burps coolant. Never overheats, though once on a hard tow, it smelled hot. The amount of coolant it loses is not great, but it is repatative, but irregular. I need to add a quart of water to the burp tank about every 500 miles.

On Bronco IIs cologne engines, you had to remove the upper radiator hose and fill, then reattach, and fill the radiator the rest of the way. Failure to do this resulted in numerous cracked heads and blocks. I do not find a similar instruction/warning for the 4 liter V-6 in the '92 Exp which is also of course powered by a cologne v-6.

Has anyone else had this problem, is there a better way to fill the coolant jacket? Is there a problem with an air pocket in the water jacket????

 

[jmdirk]

Getting all the air out can be a bit problematic. The factory procedure is pretty basic. Others on the site have found it help to have the nose of the truck elevated somewhat helps in bleeding it the system.

COOLING SYSTEM BLEEDING
AEROSTAR, EXPLORER & RANGER
1. Fill cooling system with 50/50 mixture of coolant and water. Pause several minutes
for circulation. Fill radiator to filler neck seat. Install radiator cap fully, then back
off to first stop.
2. Turn heater controls to maximum. Start engine and operate at 2000 RPM for
approximately 3-4 minutes. Turn engine off. Using a protective rag, carefully
remove radiator cap. Add coolant to filler neck seat.
3. Install radiator cap fully, then back off to first stop. Start engine and allow to
operate at 2000 RPM until upper radiator hose is warm. Check heater output. Turn
engine off. Using a rag, carefully remove radiator cap. Add coolant to filler neck
seat if necessary.
4. Tightly install radiator cap. Remove small cap (large cap is for windshield washer
reservoir) on coolant recovery reservoir. Add 1.1 qt. (1L) of 50/50 mixture of water
and coolant to reservoir. Install reservoir cap