Mulestang

Been reading up on servicing my coolant, and have come across a few threads in which people recommend flushing the system with the thermostat removed. I have a bottle of Zerex flush I want to run through it, and plan on following the instructions (15 minutes of circulation when warm), but I'm concerned about flushing with no T-stat. When the T-stat is removed, will the housing and O-ring maintain a leak-free seal? It looks like the O-ring rests atop the T-stat. Has anyone flushed with the T-stat removed? Any advice before I tackle this tonight? Have all the supplies ready to go (gold coolant, distilled water, etc.) Thanks.

Martian

Give it a shot. You're not going to be just driving around without a seal, you're only doing a flush. If it does leak a ton, turn the truck off, throw the thermostat back in, and try again.

techrep

iTrader: (1)

This is the way it should be done...it will allow the flush to completely circulate throughout the cooling system right away vice waiting on the T-Stat to open and close..remove the T-Stat and bolt the housing back on..I believe the housing has it's own gasket. remember to select heat in the cab to ensure the heater core gets flushed too. you should install a new T-Stat after the flush is completed.

Martian

I don't remember if it has its own gasket or not but I know the two parts mate very well, I'd be surprised if there was a leak more than just a few drops if there wasn't a gasket.

Mulestang

Flush complete. I think the Zerex Super Flush was money well spent. Initial drain was rather clean. The flushes that followed initial Zerex flush treatment yielded a dark residue that settled to the bottom of my drain bucket. After 4 refill/flush cycles, the distilled water ran clear. Unfortunately, I was only able to get 1.5 gallons of coolant in after the final flush/drain...which was odd, because all previous drain/refills took 2 gallons. I need to drain a little more today and add coolant.