Where is the thermostat on a 1991 F350 diesel?

Answer 1

Just in the middle of changing mine. 7/31/2010 Remove both negs on batteries. Drain radiator down about 2 gallons. Remove top hose and plug motor hole with clean rag...nuts drop in any hole. Release belt tensioner slack belts and remove then remove bolts and alternator, wires ..watch wire. I broke one have to fix. Good luck getting it out if it is a Nevile like mine..large. Remove 2 bolts from air pump and let third rotate and hang loose and swing back from motor. Follow rag plugged line to engine. There is one stud /bolt and one bolt. Remove nut / strap from stud and then stud out. Remove other bolt. Remove the neck...you are now at the stat!!!... I just put mine in boiling water...it opened. Now I'm worried about a bad water pump or clogged radiator. Believe it is pump the rad looks good. Took about 3 hours to get here. Probably about 2 hrs back now I know what is where. Warning, the stat needs to be a exact match because there should be no by pass in the stat. The neck has a by pass and SS check ball which seems ok on mine. Should be clean and ez movement. Still forking out $15 for a new stat...too much work to not replace it. Will keep the used as a spare. GOOD LUCK!! PS....Hope I noted everything. Reverse order to install.