Save yourself the oney of having someone block test it. Buy yourself a block tester kit. Find a local tool guy, Mac, Snap-on or whoever and buy one. It comes with a container of blue fluid and you just get the truck hot and take the cap off CAREFULLY and put the end of it in the opening of the reservoir and squeeze the ball a bunch of times. Dont suck in any anti-freeze if it's to high then suck some out. If the fluid turns yellow then so might you! Kits aren't to much, cheaper than a diag. charge. Good luck!

 

Damn, GREAT advice! Geez friend, thanks! I'll do that tomorrow once I get the new t-stat in.

Pat