put a new cap on that rascal too..

 

well pressure tester sure says there is a leak somewhere. loses about a pound every 8 minutes. spent about 20 or so minutes playing around with the tester. when i was done and removed coolant was down about a pint or so. who knows where that went? no signs of leakage anywhere externally. so if it is a really stubborn air pocket. how do i get it out?

 

well went out to see if the engine had cooled down. the top hose was sucked flat. - first time ever i have seen that. pulled cap hose popped back into shape and coolant was full. started and ran engine for a minute. coolant level started to rise up into the radiator neck as it got warm also a few large air bubbles. never seen that before. usually just the heavy white foam. revved the engine a few times and no heavy foaming like it usually does. but temp ran right up. when the gauge shows hot (near the top) the temp on the top radiator tank was around 230. hose from engine was around 200. bottom hose to engine 165.

 

Yep, still got an air pocket. If there is a big *** hill somewhere nearby, leave the cap slightly loose, drive there, and park the truck at as steep an angle as your butt will tolerate. Then try burping out the system.

Replace your radiator cap, it is supposed to allow the system, as it cools, to draw coolant from the overflow bottle, back into the radiator, the upper hose sucking flat, indicates that portion of the cap is malfunctioning.

 

replaced the cap with a stant safety cap. drove home now my overflow is overflowing. okay on the hill. tilt it left right up down? can i just jack it up 15" and then what?

 

Just drive straight up the hill.

Is your truck overheating??

 

the gauge shows overheating, seems to be running hot. but when i put the laser on it, it shows different temps. i think i posted them earlier. i think the top tank was 226 or so.

 

Three vehicles with the same problem, hmm...
What kind of coolant/water are you putting in the cooling system?

 

on the first two i used a store brand coolant concentrate and distilled water. i believe that 89 318 had a cracked head in the end. on the 96 it just started overheating one day and thats when i noticed the foaming in the radiator opening. so i just got rid of it. now this time same thing. over heating (on gauge) and pump went bad. so replaced pump and flushed radiator with vinegar. now i have it filled with autozone green conventional coolant and this time i used radiator additive instead of distilled water. it was 2 dollars for a gallon supposed to mix with the concentrate but better than just regular water. yesterday after i pumped all the pressure in and had to add more coolant it still ran the gauge all the way up when i drove it but a few hours later when i checked the engine that was the first time ever the top hose was flat. so i took the advice given and replaced the cap. on a side note now when i rev the engine with the cap off i just get some bubbles not the heavy foam.

 

Probably still have an air pocket in there.