Dealer coolant change

Ditto TnShooter. The radiator petcock drain has an o-ring so you just close it until it stops.. no need to go any further. It's very unlikely to back out on its own as well.

 

I've had many of those stupid plastic petcock snap off as soon as you try to twist it. I found this tool that helps getting at the ones buried deep down where there's not a chance you'll get your hand on it. It doesn’t lock on like a normal socket so I usually tape it to an extension.

Thexton THE485

 

I'll give it a try next time but does that really work?
I thought it was simply a flat blade to grip pliers onto

wow had no idea such a tool existed
I need that...

 

Curious if the petcock drain plug can be fully removed and then coated with a light amount of silicone so that it doesn't "stick" and break later.. probably would contaminate the cooling system so not worth it.

 

It does have wings.
But the socket fits right over them.

FWIW, I didn’t figure this out myself.
A Toyota Tech gave me that little tip

 

Another option is to replace the plastic thing with a brass petcock valve.

$7 Dorman 61104 Drain Cock-Brass-Standard-1/4 In. NPT Compatible with Select Jeep Models

https://www.amazon.com/Dorman-61104...616&sprefix=Petcock+valve+cool,aps,124&sr=8-2

Although it would be better to find one not made my Dorman.

 

Nothing wrong with a small dab of dielectric or caliper grease on a o-ring. Sometimes they'll be flat after sitting in the bore for so long, I keep a small o-ring selection close by so i can replace them as needed.

The only way those plastic petcocks will break is if somebody overtightened it

 

I'm guessing all radiators are 1/4" NPT petcock then
or whatever they are
the uniformity would make sense given they're all typically plastic flatblade valve and supplied to automakers by the same manufacturers (Nissens, etc.)

 

I'd expect more trouble with metal petcock than plastic. Metal will get corroded, especially mounted at the bottom of a radiator near the ground

 

yup! I use the socket to loosen it every time. Works perfectly

 

I’ve only ever seen 2 sizes. Small ones and big ones. I’m guessing there’s other sizes, I think the small ones I’ve seen aren’t pipe thread, and are metric, maybe m8 1.25. The majority of issues I’ve had with them is on water pump bleeders that use a plastic petcock.