I need a little info please. It's time to change the tstat and coolant. Will on the quickserve site i noticed they list a tstat and a seperate seal, the one I bought from cummins has a seal built onto the rim of the tstat. Can anyone tell me if the second seal is needed or not? I would also like to chemiclly flush the cooling system, anybody have any recommended products for this?
Alex

 

i dunno about the coolant or anything but i put a thermostat in mine from cummins jus like u said with the rubber seal around it and it works fine for me, no other seal or anything. no leaks either. hope this helps

 

Not to hijack, but does anybody have that cummins part number, I also need to service my cooling system. Thanks

 

i believe you are fine. but get a lower thermo 180 instead of 190 stops all the fluctuating temp.

 

Part number from cummins is 3946116. They only had a listing for 180 degree thermo for my cpl.

 

Dodge sells them seperate. tstat and then the seal. That seal is $11 by itself at the dealer.

Cummins sells it as a kit with the seal already attached to the tstat.

This is the standard part# 3967195

 

Cummins 180* T-stat (I recommend it also) - PN 3967195

RJ

 

Get the 180 t-stat, I just did, and then go to wal-mart and get the fleetguard antifreeze. You will notice a difference, just did mine 2 weeks ago and wish I would have done that a year ago. No more watching the temp guage go up and down all the time.

 

I've got thermostat, genuine cummins parts, on the box says 05014568AA. The rubber seal on the thermostat says 3934379, "towards radiator". The guy I got it from said he used the same number in his '96. Is this an old number or a part that won't fit?

 

That may be the 190* T-Stat.... which originally came with our trucks, and was redesigned by Dodge...for faster warmups.
If towing a lot, working/racing truck hard or living in the heat in the south, many have had better luck with the 180* T-Stat. It prevents the coolant temps from climbing easily and becoming the limiting factor.

RJ

 

Any MPG lost with the 180 deg vs 190 deg Thermostat?

 

Not by me, or anyone I've spoken with. Theoretically possible, I suppose, in cooler climate, but not with our mild winters and 7 months of summer!

FYI - for those interested. I have heard some crazy variations in price for the Cummins PN 3967195. Should be in the $30-40.00 range from any Cummins parts place. IMO, this is not a part to save a few bucks on from the local parts place.

RJ