Radiator Help

[Ole Blue 68]

Ok, my radiator's been pushing a lot of anti-freeze through the overflow tube, (to the point where my radiator's half empty). So my first question is where should the proper fill level be for one of our trucks? This seems way too low for me but who knows.

Second question is, if this is too low what could be causing it? Clog in the radiator? Stuck thermostat? Although, I don't think it's a stuck thermostat.

[OLDIRON69]

about an inch below the filler... Is the truck running hot? If it is running a little warm and suddenly drops back down to operating temp it most likely is your stat.

[jhow66]

Change your rad. cap first. The release spring is probably broken in the old one causing it to open at to low of a pressure.

[Ole Blue 68]

OldIron- This is way down. I can't see it without a flashlight. I figured about an inch would have been normal.

Jhow- Never thought of the rad. cap. Would that effect the overflow tube?

[jhow66]

Originally Posted by Ole Blue 68

OldIron- This is way down. I can't see it without a flashlight. I figured about an inch would have been normal.

Jhow- Never thought of the rad. cap. Would that effect the overflow tube?

Yes. If you have a 16 lb pressure cap, the cap will release pressure to the outside at this # so as not to burst hoses or anthing else. Plus the higher the #'s, the higher the boiling point. So if your cap is worn out ( broke or weak spring) it may be releasing fluid at ,say 8lb. Try it. Might be a cheap fix. Also fill rad. and leave cap off and watch it after it warms up. If you see air bubbles. you may have head gasket problems or a cracked head.

[Ole Blue 68]

Originally Posted by jhow66

Yes. If you have a 16 lb pressure cap, the cap will release pressure to the outside at this # so as not to burst hoses or anthing else. Plus the higher the #'s, the higher the boiling point. So if your cap is worn out ( broke or weak spring) it may be releasing fluid at ,say 8lb. Try it. Might be a cheap fix. Also fill rad. and leave cap off and watch it after it warms up. If you see air bubbles. you may have head gasket problems or a cracked head.

I was afraid of head problems at first too but after filling and checking it w/ the cap off, everything looked ok; no bubbles.

I checked out where the overflow tube comes in at and see what you mean with the cap. So, I bought a new 16lb cap at NAPA and I'm hoping that it proves to be the cheap answer to my problem. That's why I love this forum!

Thanks for the info!