Novak Conversions Jeep Wrangler TJ radiator

Help with cooling system flush, thermostat & water pump

Redjeepht

Member
Original poster
Joined
Jul 8, 2024
Messages
75
Location
Colorado
Hey ya'll, I am preparing to change my thermostat and water pump, I know its recommended to flush, but i'm not finding out specifics on how people are tackling those jobs together.

One popular way to flush the cooling system is without messing with the thermostat, (using a hose or filling, drain, repeat). The other way, in the FSM, says to drain it. To flush the RAD. Remove radiator hoses, shoot water from bottom, then it will come through the top To flush the engine, remove the thermostat, replace housing(without thermostat) Add water from the large upper hose from radiator, and it will come out the bottom hose from the water pump that connects to the bottom radiator (where you put the water to flush radiator).

I do not have my heater core hooked up right now, the hose is bypassed. I'm nervous to do this flush, because theres a lot of different information on the forum and youtube...

Also, the thermostat & pump replacement have me confused. I've seen mixed claim (you need to put liquid gasket on the gaskets, you dont need to, you need to teflon all WP bolts, only 1, or blue threadlocker on some or all).

From what i'm thinking, according to the FSM, I will start my flush "mid way" through the thermostat replacement, install new thermostat, WP, then fill it with coolant. I'm sure this is much easier than i'm thinking about it. but for some reason the flushing part is adding some confusion to everything. I'll attatch some pictures showing where I think the water will enter/exit during the flush.
 
https://wranglertjforum.com/threads/jeep-wrangler-tj-water-pump-replacement.279/

I recall this being a very good write up...and the video is solid.


On the flush. If you are looking to do that, I believe Thermocure to be the best.

It needs to be run in the system for a day or so, let it eat up the rust in there etc, if that is what you believe is the issue.

Is your Water Pump leaking badly? Or can you run it for a day off an on? If you can, here's what I'd do..

Add Thermocure. Let some coolant out for room if needed.
Close it up, and run it for a day off an on, maybe 2.
Then, let out all the fluid.
Change the water pump, and leave the Thermostat out.

Fill with Distilled water ONLY.
Start it and run for 3-4 minutes.
Drain all the water.
Repeat until the water is clear. The engine won't get too hot, that's why you don't run it long, with no Thermostat it goes everywhere to clean it out.
When it's clear, take off the thermostat housing and put in a Mopar 195 Thermostat.
I would drill the hole in it to burp. and put it in by the video above.
Fill with Zerex G05 Coolant 50/50 with Distilled water only.
Fill the overflow.
Run the engine on a hill with the front end higher, not "Needed" but helps sometimes to burp the system.
Let it cool, open and fill, then make sure overflow bottle is full.
 
Novak Conversions Jeep Wrangler TJ radiator