Coolant Service

[MarksmanAkula]

Looking to service my water pump, upper and lower hoses.

Whats the best way to drain the KJ's system?

 

[LibertyTC]

Since you will be replacing lower rad hose anyways, don't touch the rad's drain petcock. Known leaky issues or worse if you break it open.
I would just drill a 3/8 hole in the lower rad hose and let it drain out that way.
Install a new Mopar thermostat as well while u are there.
See HJ's post # 7 this thread> https://www.jeepkj.com/threads/radiator-questions.63242/
Also must add our Jeep's need HOAT coolant or Zerex G-05 only.

 

[uss2defiant]

remove thermostat housing and lower rad hose to drain. undoing the WP will drain as well.
I've used my petcock as well with no issues. YMMV

 

[MarksmanAkula]

Since you will be replacing lower rad hose anyways, don't touch the rad's drain petcock. Known leaky issues or worse if you break it open.
I would just drill a 3/8 hole in the lower rad hose and let it drain out that way.
Install a new Mopar thermostat as well while u are there.
See HJ's post # 7 this thread> https://www.jeepkj.com/threads/radiator-questions.63242/
Also must add our Jeep's need HOAT coolant or Zerex G-05 only.

Got a new thermostat and coolant as well. Just didn't know the best way to go about draining it.

Avoid the petcock?

 

[MarksmanAkula]

remove thermostat housing and lower rad hose to drain. undoing the WP will drain as well.
I've used my pepcock as well with no issues. YMMV

thank you!

 

[uss2defiant]

if you haven't touch your petcock in a while then I think most people avoid touching it.
There's an Oring on the end of it that may cause sealing issues if it damaged.

there's also the engine block coolant drain plug as well. Something that I don't personally dare to venture.

 

[MarksmanAkula]

if you haven't touch your petcock in a while then I think most people avoid touching it.
There's an Oring on the end of it that may cause sealing issues if it damaged.

there's also the engine block coolant drain plug as well. Something that I don't personally dare to venture.

I more just wanna replace the hoses and parts, not really looking to drain block either.

 

[uss2defiant]

probably a good opportunity to 'flush' your coolant.
What i've done in the past is drain as much as I can, install new WP and fill with DI water. Reinstall the old t-stat.
I run it till hot drain and refill with DI water. Repeat a few cycles then install new t-stat.
fill with 100% coolant to get your ratio.
Total in the 3.7 engine is 14 quarts so you can do the math.

YMMV since you'll have to deal with all the coolant to recycle.