Thermostat replacement

[Snap'd]

Why am I needing to drain the radiator to replace the thermostat? I understand there will be some fluid loss when I disconnect the hose, but I don't see the advantage of that much loss by opening the petcock.
Your thoughts please

 

[JerryD]

I don't. I use these to clamp the hose. When done, I burp & top off

 

[Speartip]

Just replaced upper rad hose & thermostat housing yesterday . Very little fluid loss.
When Jeep is cold not much up that high . Draining rad would be a waste .
Open rad cap to release any pressure . Disconnect hose, unbolt thermostat housing .
Replace in order . Good to go.
If it was lower rad hose that would be a totally diff story .
Welcome to the forum .

 

[JeepJeezy]

Why am I needing to drain the radiator to replace the thermostat? I understand there will be some fluid loss when I disconnect the hose, but I don't see the advantage of that much loss by opening the petcock.
Your thoughts please

Who said you needed to drain it? I didn't drain mine when I replaced the t-stat. Only the littlest bit of coolant was lost.

 

[JerryD]

Who said you needed to drain it? I didn't drain mine when I replaced the t-stat. Only the littlest bit of coolant was lost.

Prestone?

Actually, I've seen a lot of videos stating that you need to drain it for this procedure. IIRC, so does the service manual, but totally unnecessary.

 

[BLACKJKU]

Maybe when the T-stat goes bad most will figure it's time to also change and flush the cooling system.