replace thermostat as part of PM

"If it aint broke then don't fix it"

 

CAT engines will let you know when you need new thermo. I drive slip seat in a fleet of about 45 tractors, and it's obvious. You're running cool then all of a sudden ya need to flip on the fan. Then it runs another 100 miles cool, then needs to be flipped on again. When there's no rhyme to the reason why it's cool or hot, then it's time.

 

Some of those bolts in the thermostat housing like to get seized up after a few years. If you are draining the coolant, it would be cheap insurance to change them now and put some anti seize on the bolts. Like the saying goes, an ounce of prevention...

 

I made the mistake of changing my thermo's over 10 years ago. I was told to change just cause they were original. the temp always worked great. after new thermo's. never the same. seems anything original works longer & better than replacements. my old temp would hold 190 if on a steep hill & I put the manual fan on, it would drop from 200 to 190 real quick while going up hill with 80,000 lbs. in your case I would just put a couple spare parks in side pocket, but not change anything that is working. you can get 2-3 bad thermostats in a row. quality is not in the parts anymore.

 

i used to change mine every time i flushed the cooling system about every 2 years

 

That is what parts warranty is for.

 

NO one warranties the labor though.

 

Ok well, that's what happens when you diy. If something is wrong with the part and you don't want to change it, who's fault is that?

 

Here is why I say if it is not broke do not fix it.. I am talking from experience. I have a 95' intl. I am the preventative maint type of guy. I also have learned quite a bit about certain parts. for example looking over my truck one day, I decided to replace one of my many air valves. it was 14 years old. still worked fine. just the age & the looks made me want to replace. the o.e.m. replacement was plastic & looked like a china cheap part. it lasted a lil more than a year, then started leaking. why did I replace? well for $10.00 I figured good preventative maint. I have done this many times, just to find the original part was better off in place until it no longer functioned. I have found a co that makes the metal valves. as far as many other parts. I do believe in replacing before they go bad, like belts hoses, batteries, thermostats are just not on my list. I guess it depends on how easy it is to change. if it is very difficult, then I would change them when in the engine, but if not hard at all do do, I would leave them in, if they work properly now.