My truck has been leaking coolant out of the overflow hose, I came out to it this afternoon and my wife was in it with it running and the AC on, the coolant was pouring out the overflow. we got it and took off, about 5 min. later the low coolant light came on. It has done this before too and I cant for the life of me figure out why? any ideas? -Jeff

your cap for the coolant might not be holding the psi that it needs too keep the fluid in the res, and might need a new 1 . oh and what temp is it getting to ? if its going above 210 your thermostat mite be shot too.

never goes above 210

have you ever heard of the cap going bad?

Yeah the dealer replaced mine the last time in for service. Did not know there was anything wrong but they said it was replaced adnI figured it was maybe because of something like this.

Brian

ttt

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when you have a blown HG does it always come out of the overflow tube? I would think there would be a diesel smell in it or oil in the coolant or coolant in the oil?

Last week drove mine for about 5 miles and it wasn't warming up, still was ambient temp. so i pulled over and shut it off and coolant was pouring out of the overflow. so when i pulled the cap it probably had about 30 psi behind it. So i put a pressure tester on it and let it run for about an half hour and the needle didn't move so i know it wasn't a head gasket or injector cup/s. Then when it blew the cap off i couldn't find it so i bought a new one and it seemed fine for about a day then it did it again. So i put both thermostats in it and have had no problem for about 2 weeks now. But does anyone know how to properly bleed the coolant system in an 01' lb7? any input would be apperciated.

My truck has been leaking coolant out of the overflow hose, I came out to it this afternoon and my wife was in it with it running and the AC on, the coolant was pouring out the overflow. we got it and took off, about 5 min. later the low coolant light came on. It has done this before too and I cant for the life of me figure out why? any ideas? -Jeff

Mine is blowing out the overflow too when it gets warm on me. Seems to be running in the 230* area. Clogged up rad, headgasket, EGR cooler maybe? I think i'll see what i can do to delete my EGR completely, just to factor that out. And a pressure test. As i don't see any leaks other than it coming out of the overflow.

wsucowboy. Were you the guy a while back that had oil in the antifreeze and there was something about a water pump?

If not, please disregard.

Check head gaskets.

Feel the hose on the driver side of truck when it is cold. If it is hard, get out your check book.

If not, you maybe O.K.

Don't freak out, do the simple stuff first like the cap, and then move from there. I would have sure the system is flowing good as well.

SDREESE, the only way I have ever done it is loosen the bolt on the upper hose neck, and fill the system till it pours out of that, then tighten it, and fill the res. the rest of the way, you may have to top off later, but I have never had any propblems doing it this way.

Good luck to both of you!

When I just did my water pump that is how I bled the syten of air.