Looking for opinions on my proposed cooling system overhaul

[strichzwei]

Hi guys, I have been doing a bunch of reading and greatly appreciate this forum, it would be reassuring to get a bit of feedback on my first ever coolant flush plan just to make sure I have assembled the information in this forum correctly for my situation. This is a new to me 2004 4.0 TJ with 90K miles, previous owner just replaced radiator with cheap aftermarket and is leaking, I believe all other cooling system parts to be original.

I plan on replacing most all cooling parts, in hand - radiator, radiator hoses, thermostat and gasket, water pump, fan clutch, heater hoses, new radiator cap, 2 gallons zerex GO5, auxillary belt, temp sensor (thanks for forum list).

Flush plan, prior to replacing any parts:

1) Drain radiator at petcock and drain block at block plug.

• Does this purge all coolant?

2) Remove heater hoses and flush heater core with distilled water in both directions (just planning on using a funnel to pour in a gallon of distilled water and letting gravity flush it out), reconnect hoses.

3) Remove overflow tank and clean.

4) Fill system with distilled water and Prestone “flush+cleaner”.

• Instructions say something about just draining radiator and refilling with “flush+cleaner” and topping off with coolant (?). Any issue just using all distilled water and prestone “flush +cleaner” or does the “flush+cleaner” need coolant in the system for some reason to work?
• Will I be able to refill radiator and block through radiator cap or do I need to remove the temp sensor to fill block?

5) Run car up to temp for an hour, let cool.

6) Drain radiator and block like above, and refill system with only distilled water

7) Run car up to temp for an hour, let cool.

8) Repeat #6 and #7 until drained distilled water is clean (if things look really nasty maybe start at #4 again and leave the prestone “flush+cleaner “ in for several hours of driving…….).

9) Drain radiator and block like above

10) Replace parts and fill with coolant 50/50.

11) check for leaks.

Thanks,
Scott

 

[Not_Invented_Here_]

Just some thoughts based on my experience - disregard if you already know or thought of these things...

I assume you mean this in steps 5 + 7(?) but don't forget to burp the system when you're done.
Check that metal inlet tube that goes to the thermostat. It can be a bitch to remove without ruining it and is cheap enough to just replace while you have it apart.
If you don't have any on hand, make sure to get some teflon tape for threads.
Inspect the belt tensioner and idler pulley while you're in there.
Gasket scraping is a PITA so get some razor blades or a proper scraper and some shop towels to stuff in openings to prevent old gasket from falling in. You don't want that getting in the wrong places.
If you have A/C, check that condenser in front of the radiator and blow out any leaves/bugs/gunk from those tight spaces.
A 1/4" drive ratchet makes life easier in those tight spaces on either side of the radiator
Channel locks help tremendously if you have constant tension clamps on your hoses, otherwise those suck to get off.

I did the same overhaul relatively recently on my 04 with auto trans and while it seemed a bit overwhelming to a first timer like me, it was actually fairly straightforward. Good luck and don't hesitate to ask other questions if you got'em.

 

[strichzwei]

Just some thoughts based on my experience - disregard if you already know or thought of these things...

I assume you mean this in steps 5 + 7(?) but don't forget to burp the system when you're done.
Check that metal inlet tube that goes to the thermostat. It can be a bitch to remove without ruining it and is cheap enough to just replace while you have it apart.
If you don't have any on hand, make sure to get some teflon tape for threads.
Inspect the belt tensioner and idler pulley while you're in there.
Gasket scraping is a PITA so get some razor blades or a proper scraper and some shop towels to stuff in openings to prevent old gasket from falling in. You don't want that getting in the wrong places.
If you have A/C, check that condenser in front of the radiator and blow out any leaves/bugs/gunk from those tight spaces.
A 1/4" drive ratchet makes life easier in those tight spaces on either side of the radiator
Channel locks help tremendously if you have constant tension clamps on your hoses, otherwise those suck to get off.

I did the same overhaul relatively recently on my 04 with auto trans and while it seemed a bit overwhelming to a first timer like me, it was actually fairly straightforward. Good luck and don't hesitate to ask other questions if you got'em.

Awesome, thanks!

 

[RMETeeJay]

1) Drain radiator at petcock and drain block at block plug.

• Does this purge all coolant?

I believe there would still be some old coolant/sludge in the block. I would recommend flushing the block too.

 

[TheBoogieman]

It's a self burping cooling system if you do it correctly. Absolutely no need to burp anything except your infant child.

 

[MountaineerTom]

I used prestone flush/cleaner also but I just filled up with straight water and then drove it about 50-60 miles then flushed a couple more times. I drained the block at the end but some don’t.

I personally like using Permatex high temp thread sealant instead of Teflon tape. I used it on my block drain plug, temp sensor and the metal pipe on the water pump. I just made sure not to put it on the very end so it didn’t get into the coolant.

I agree with @Not_Invented_Here_ about the metal pipe. Cheap enough to just replace. I used a Dorman brand and I cleaned the paint off the threads before sealing and installing after reading about someone else having threading problem because of to much “stuff” on the threads.

I’d reuse the constant tension hose clamps if you have them. I tried worm style clamps and had various leaks every time the weather cooled off.

You can just use tap water for all the flushing and then use distilled for the final one and fill up. Nothing wrong with using all distilled water, but if you’re on a budget it might save you a few dollars.

 

[MountaineerTom]

And, if you pull the block drain, it looks like a 3/8 drive but it’s not. It something like 8mm. You can get them on amazon or grind down a 3/8 drive to fit.

https://www.amazon.com/gp/product/B008TOHAVG/?tag=wranglerorg-20

 

[Midtenn]

I flushed with thermocure. It took probably 15 gallons of water before it ran clear.

 

[strichzwei]

Thanks for all the feedback guys.

 

[AjRagno]

I think you’re probably replacing some perfectly good parts. The fan clutch in particular should not be replaced unless it’s spinning freely. The water pump, if OE Mopar, is also a better design than the current Mopar water pump and may still be perfectly functional. Many of the factory Mopar parts are no longer made by the OE supplier so be careful or you may be downgrading. My original water pump made it 230,000 miles.

The only radiator you should consider is Mopar. Rock Auto usually has the best prices.

The socket to drain the block is 8mm.

https://www.amazon.com/gp/product/B00FRLBF4M/?tag=wranglerorg-20

The best thermostat is Stant 45359.

https://www.amazon.com/dp/B000C7YRNM/?tag=wranglerorg-20

 

[ejay]

It's a self burping cooling system if you do it correctly. Absolutely no need to burp anything except your infant child.

All indications from those of us that have done this more than once is that the self burping system is not self burping.

 

[Lou]

The closest thing to a self burping cooling system is one that uses a surge tank. TJs do not use a surge tank.

 

[TheBoogieman]

All indications from those of us that have done this more than once is that the self burping system is not self burping.

19 Jeeps and I've never burped one. Maybe my Jeeps are special.
When the engine is cool open the Radiator Cap and make sure it is filled to the top with Coolant. From there locate the Coolant Reservoir and make sure it is filled to the level marked on the side of the container. Now this is where the confusion comes as "burping" the cooling system comes from decades ago and is not necessary now. When the Cooling System is properly filled the system will purge its self when it runs and shuts down. The important part is run the engine to completely make the nominal operating temperature and when it cools the Coolant will move around. This is where most people open the Radiator Cap to check which introduces more Air into the system. Do not open the Radiator but rather check the Reservoir which you should see actually lost Coolant is it gut sucked into the Radiator thus topping off the system.

 

[TheBoogieman]

Apparently I'm not the only one with a special Jeep.
" The TJ's cooling system is definitely self-burping, I've yet to need to burp mine after refilling the cooling system over the last 23 years of TJ ownership. It will eventually bleed the air out through the thermostat and up the top radiator hose to the inside of the radiator. The coolant flows fast enough that trapped air gets mixed thoroughly into the coolant so trapped air easily passes through the center of the thermostat whether there's an additional bleed hole drilled into its flange at the top or not. "

 

[Midtenn]

Apparently I'm not the only one with a special Jeep.
" The TJ's cooling system is definitely self-burping, I've yet to need to burp mine after refilling the cooling system over the last 23 years of TJ ownership. It will eventually bleed the air out through the thermostat and up the top radiator hose to the inside of the radiator. The coolant flows fast enough that trapped air gets mixed thoroughly into the coolant so trapped air easily passes through the center of the thermostat whether there's an additional bleed hole drilled into its flange at the top or not. "

Not everyone wants to wait on eventually. Some people want the system to the air to be removed immediately. I use a vacuum to remove the air and then fill.

 

[Not_Invented_Here_]

19 Jeeps and I've never burped one. Maybe my Jeeps are special.
When the engine is cool open the Radiator Cap and make sure it is filled to the top with Coolant. From there locate the Coolant Reservoir and make sure it is filled to the level marked on the side of the container. Now this is where the confusion comes as "burping" the cooling system comes from decades ago and is not necessary now. When the Cooling System is properly filled the system will purge its self when it runs and shuts down. The important part is run the engine to completely make the nominal operating temperature and when it cools the Coolant will move around. This is where most people open the Radiator Cap to check which introduces more Air into the system. Do not open the Radiator but rather check the Reservoir which you should see actually lost Coolant is it gut sucked into the Radiator thus topping off the system.

Not saying you're wrong but that's not procedure I was taught to follow in order to burp the system. We left the rad cap off completely, then we started it and let it run until it eventually got up to temp. We didn't and wouldn't remove the cap after reaching running temp. We also jacked up the front end so that the rad cap was the highest "point" in the system. I'm all ears about this being unnecessary/overkill/whatever but the process you're describing is not what I understand to be the common manual burp.

 

[ejay]

19 Jeeps and I've never burped one. Maybe my Jeeps are special.
When the engine is cool open the Radiator Cap and make sure it is filled to the top with Coolant. From there locate the Coolant Reservoir and make sure it is filled to the level marked on the side of the container. Now this is where the confusion comes as "burping" the cooling system comes from decades ago and is not necessary now. When the Cooling System is properly filled the system will purge its self when it runs and shuts down. The important part is run the engine to completely make the nominal operating temperature and when it cools the Coolant will move around. This is where most people open the Radiator Cap to check which introduces more Air into the system. Do not open the Radiator but rather check the Reservoir which you should see actually lost Coolant is it gut sucked into the Radiator thus topping off the system.

Four Jeeps, never worked for me. I've always ended up getting air out of the system. Sometimes months down the road after random temp spikes.

 

[ejay]

Apparently I'm not the only one with a special Jeep.
" The TJ's cooling system is definitely self-burping, I've yet to need to burp mine after refilling the cooling system over the last 23 years of TJ ownership. It will eventually bleed the air out through the thermostat and up the top radiator hose to the inside of the radiator. The coolant flows fast enough that trapped air gets mixed thoroughly into the coolant so trapped air easily passes through the center of the thermostat whether there's an additional bleed hole drilled into its flange at the top or not. "

Auto part stores regularly sell thermostats for TJs without a bleed hole. Even with one....as stated...I've got air out of the system months down the road by following standard burping procedures.

This horse has already been beat in this forum. It's ground chuck by now.

 

[strichzwei]

I think you’re probably replacing some perfectly good parts. The fan clutch in particular should not be replaced unless it’s spinning freely. The water pump, if OE Mopar, is also a better design than the current Mopar water pump and may still be perfectly functional. Many of the factory Mopar parts are no longer made by the OE supplier so be careful or you may be downgrading. My original water pump made it 230,000 miles.

The only radiator you should consider is Mopar. Rock Auto usually has the best prices.

The socket to drain the block is 8mm.

https://www.amazon.com/gp/product/B00FRLBF4M/?tag=wranglerorg-20

The best thermostat is Stant 45359.

https://www.amazon.com/dp/B000C7YRNM/?tag=wranglerorg-20

I hear you about the parts, this will be the daughters jeep and she wont be living near by for a while, really want to get it baselined and reliable for some time so this is really preventative......really didn't want this to turn into a "burping" thread.

 

[mrblaine]

All indications from those of us that have done this more than once is that the self burping system is not self burping.

Not sure why this hasn't become accepted knowledge yet but it is a self bleeding system if you drill a hole in the thermostat, 1/8", right in the flange, put that on top, solves all the air issues all the time.

The original thermostat had a little bleed hole with the ball in it, they changed it, when that happened, they got harder to bleed, putting the hole in the flange works every time.