Wrangler TJ Radiator Replacement

[JP13]

Now that's a good answer.

 

[mrblaine]

Haha, I love it!

I think he's referring to an all aluminum radiator without the plastic end caps. Somehow I think you already knew that though

If you find the right place, there are nice explanations over the development of the composite tanks used on the aluminum radiators in the TJ. Especially if you find the one that shows the composite tanks are actually stronger and can handle higher pressures than the old copper and brass radiators. Folks refer to them as "plastic" but that's the same as referring to all axle shafts as steel. Yes, they are all made of steel but which alloy and what heat treating was done has a very big effect on the end result.

The same is true for the composite tanks.

 

[mrblaine]

Damn. I guess my oversize tires are pointless since they didn't come stock. Lol

They would be pointless if you attempted to use them as intended and they weren't up to the task. That is rarely the case and the stock tires do hold air very well throughout their intended lifespan, they are rarely out of round, and unless you change their intended purpose, they work pretty darn well.

I'm running a set of JK take-offs on my 04 Unlimited and I'll dare anyone to show up with a tire that rides nicer, is quieter, or has more comfort. That and they are just downright cheap. I don't know of another 32" tire that you can readily find for 400ish bucks and have that include rims.

 

[mrblaine]

The TJ has a lot of areas that can benefit from aftermarket upgrades, the cooling system is just not one of them. Lots of us wheel out in the deserts of SoCal, me included, and if the factory cooling system wasn't adequate, you can bet we'd be experts in knowing how to upgrade it so it was.

We are however expert in realizing the factory cooling system is more than up to anything our local deserts can throw at it. We have come to realize through experience that "upgraded" aftermarket radiators are anything but upgrades, they seldom even come close to performing as well as the OE Mopar radiator with its all aluminum core does. It would be very tough to find an aftermarket radiator that even equalled its cooling performance and tougher yet to find one that outperformed it. Really.

Here is the one in Mark's rig that is very high dollar. They won't even consider a replacement until we remove it and send it back to them.

 

[Chris]

Here is the one in Mark's rig that is very high dollar. They won't even consider a replacement until we remove it and send it back to them.

What's wrong with it that it needs replacing?

 

[Chris]

If you find the right place, there are nice explanations over the development of the composite tanks used on the aluminum radiators in the TJ. Especially if you find the one that shows the composite tanks are actually stronger and can handle higher pressures than the old copper and brass radiators. Folks refer to them as "plastic" but that's the same as referring to all axle shafts as steel. Yes, they are all made of steel but which alloy and what heat treating was done has a very big effect on the end result.

The same is true for the composite tanks.

This makes sense. I figured that auto manufacturers wouldn't make a radiator that had an had an aluminum core and composite end caps, unless there was a purpose behind it.

Everyone just assumes these aftermarket aluminum radiators are better, and I keep trying to tell them that many of these TJs still have the original radiator after 20 years! To me, that's impressive.

 

[mrblaine]

What's wrong with it that it needs replacing?

Did you miss the picture?

 

[Chris]

Did you miss the picture?

Oh crap, I did miss that!

Where's it leaking from? Looks like it's coming from around the upper radiator hose area.

 

[StG58]

The Mopar radiator for the SE showed up today. Hat tip to @Chris for the link to get one.

Initial observations:
The composite tanks are heavier duty and appear thicker than aftermarket radiators.

The metal in the crimp area around the tanks is noticeably thicker and appears to be very uniform.

The drain valve is larger and seems to be a better design.

The core finish is uniform and well applied.

All in all, the Mopar radiator appears to be a higher quality, more substantial unit all the way around. Plus, no transmission cooler plumbing!

 

[Chris]

The Mopar radiator for the SE showed up today. Hat tip to @Chris for the link to get one.

Initial observations:
The composite tanks are heavier duty and appear thicker than aftermarket radiators.

The metal in the crimp area around the tanks is noticeably thicker and appears to be very uniform.

The drain valve is larger and seems to be a better design.

The core finish is uniform and well applied.

All in all, the Mopar radiator appears to be a higher quality, more substantial unit all the way around. Plus, no transmission cooler plumbing!

Does it say where it's made? I'm curious!

 

[Jerry Bransford]

Plus, no transmission cooler plumbing!

Too bad, that can be used for other fluids like the power steering system if you don't have an automatic transmission. I had to add my power steering cooler externally, in front of the radiator since I am using the radiator's transmission cooler for my transmission.

That finned silver cooler behind the grill...

 

[Chris]

Too bad, that can be used for other fluids like the power steering system if you don't have an automatic transmission. I had to add my power steering cooler externally, in front of the radiator since I am using the radiator's transmission cooler for my transmission.

That finned silver cooler behind the grill...

View attachment 12634

There's something sexy about that photo.

 

[Bigbill]

I installed a new radiator from Jc Whitney a decade ago no problems yet.

With my experience being a car mechanic I see the new water pumps have more play in the fan bearing than the one I took out. I tend to leave the orginal water pump in there. On my '79 Chevy suburban project I rebuilt the 350 v8 at 88k the orginal owner spun a main bearing. Luckily at the time I stripped three trucks for extra parts. I drove the rebuilt engine another 100k with the orginal pump.

We played with new thermostats too to see at what temp they opened. There all different too.

My moto is if it ain't broke don't fix it. I was like you once too I changed water pump, all the hoses, radiator, too.

 

[94c2500]

This article originally appeared on Stu Olsen's website stu-offroad.com.

Parts Needed
You should always, always, always use an OE Mopar radiator when replacing your radiator. They will last longer than any radiator out there, guaranteed. Depending on whether you have a manual or an automatic transmission, you will need one of the following radiators:

55037652AA - OE Mopar Radiator (Manual Transmissions)
55037653AB - OE Mopar Radiator (Automatic Transmissions)

View attachment 503

The first task was to drain the radiator. The 4.0L cooling system holds a bit over 10 quarts. I put a bucket under the petcock on the radiator and cracked it open until a steady stream was running in to the bucket.

View attachment 504

While the radiator was draining. we pulled the rubber hose from the radiator's filler neck and then removed the coolant overflow bottle. The bottle sits in a couple of slots. Pull the bottle upwards to remove it from its mounting location. You will want to dump the contents into the bucket and rinse the bottle out. I had some fine sediment in the bottom of mine and certainly did not want to introduce it back into the system once everything was replaced and refilled.


View attachment 505

The fan shroud is held on with 4 bolts. Scott handed me a 3/8" air ratchet and it made pretty easy work of those bolts. While it could be done with a conventional ratchet, it was nice to use the air ratchet. Remove the two bolts located on each side of the fan shroud, near the top and bottom of the shroud.

View attachment 506

With the fan shroud bolts removed, you can push the fan shroud back towards the engine. By doing so, you will be able to make enough room to be able to remove the 6 bolts that hold the radiator in place.

View attachment 507

Here is a view of the driver's side of the radiator. You can see 2 of the 3 bolts (the closest one is a bit out of focus) that you need to remove in order to free the radiator. I found that the 3 bolts on the passenger side are best reached with a 3" socket extension.

Note: I got an e-mail from a Jeeper who had recently changed his radiator. He noted that the bottom two mounting bolts on his TJ's radiator did not have to be removed since the mounting holes were slotted. He as able to loosen them (without removing them) and then slide the radiator off of the bolts. You may want to check and see if yours is setup this way as it will save you some time.

View attachment 508

Remove the bottom and top hose (shown above) from the radiator. I was going to change out the hoses but after getting a chance to examine them closely, I decided to leave the factory hoses in place. I carry a spare upper and lower hose in the back of the Jeep so I am not too worried about it.

View attachment 509

With the radiator drained of coolant and the 6 mounting bolts removed, Scott lifts the old radiator out of the vehicle. You will need to wiggle the fan shroud a bit while you slide the radiator out. Although not a requirement, having a friend around when doing this part of the project sure does come in handy.

Since the cost is minimal, I picked up a new thermostat and a housing gasket. I had been carrying a new serpentine belt in my parts box for the last year. There were a few cracks in the original belt and I decided to swap the new belt in while I was doing this job. I'll keep the old belt in the parts box as a trail spare. I should comment that according to the factory service manual, small cracks running across the belt are not the "BAD" cracks you need to worry about. The cracks that run parallel to the grooves in the belt are NOT good cracks and you should replace your belt immediately;.

NOTE: If you are not replacing the thermostat or the serpentine belt, skip the following steps that detail the removal of both of these items.

View attachment 510

With the old radiator out of the way, I grabbed the air ratchet and started to remove the thermostat housing bolts. With one bolt removed, I decided it would be easier to remove the second one after removing the serpentine belt. Don't forget to unplug the electrical connector that is attached to the temperature sensor.


View attachment 511

To remove the serpentine belt, you need to loosen the bolt in the middle of the idler pulley. Mine was on pretty tight and I ended up standing on the bumper to get some adequate leverage with the ratchet handle. Once this bolt is loosened, you can loosen the idler adjustment bolt and put some slack in the belt. Be sure to note the routing of the belt around the pulleys. It can get a bit confusing when you put it all back together. If you don't have a diagram handy, be sure to draw one (just in case).


View attachment 512

With the belt removed, I took the second bolt out of the thermostat housing and carefully removed the housing. The gasket will most likely peal apart and leave some of itself on the housing and some on the engine block. Pull the heater hose off of the housing too. You can flush the heater core by removing the other heater hose where it attaches to the engine block and running a garden hose into the end of the hose you removed from the housing.

View attachment 513

Note the orientation of the thermostat so that you install the new one correctly. Remove the thermostat (it just sits in a recessed area on the block) and thoroughly clean the area of the old gasket material. Once the thermostat is removed, you can flush the block with a garden hose. Put the catch bucket under the lower radiator hose to catch the coolant coming from the block.

View attachment 514

After both the block and thermostat housing surfaces have been carefully cleaned, insert the new thermostat and position the new gasket. Place the thermostat housing over the gasket and tighten the housing bolts to 15 ft. lbs. Reattach the heater hose to the housing and if you removed it, the other heater hose going to the block.

If you removed the serpentine belt, now is the time to install it and adjust the idler pulley. I set the tension on mine as close as I could determine to the way the old belt was prior to removal.

View attachment 515

Here's a good tip I will pass along: Take a box knife and cut up the box that the radiator came in. Take a piece of cardboard and cut it to be the same width as the radiator. Push the fan shroud back as far as it will go and then slip the cardboard in front of the shroud. Now, when you slip the radiator into place, the shroud will not dig into the radiator core fins and bend them. Thanks Scott for the tip! It worked very nicely. Now, slip the radiator into position. This is another place where having a friend around will come in handy.

Note: Some distributors carry one radiator for both auto and manual transmission TJs. (cheaper to stock just one model that fits both) The radiator for an automatic has a pair of 3/8" fittings in the bottom of it where the automatic transmission fluid is routed through the bottom of the radiator to get cooled. If the new radiator that you purchase has a pair of fittings on the bottom, and you have a standard tranny, don't worry....get a couple of 3/8" plugs and screw them into the holes. This will keep "junk" out and just in case you should ever decide to get an automatic tranny, you'll already have the necessary radiator for it.

View attachment 516

After tightening the 6 mounting bolts and reinstalling the fan shroud (four bolts there), connect both the upper and lower radiator hoses. Give your handiwork a once over just to make sure you didn't miss anything (be sure the petcock on the bottom of the radiator is closed). I poured a full gallon of antifreeze into the radiator and followed it with a gallon of distilled water (well, almost a gallon....I put the last pint of it in the overflow bottle and then topped the bottle off, up to the cold mark, with antifreeze. Be sure to use distilled water. You do not want, nor need, the minerals from regular water plating out on the inside of your cooling system. (albeit, you will have some in your system if you flushed it with the garden hose as I did....well, we try the best we can!)

View attachment 517

After running the vehicle for about 5 minutes (with the radiator cap in place), I carefully opened the temp sensor. Scott said I should see some air bubbles when I did and sure enough, it burped a couple of times. He said this helps get the air out of the water jacket and prevents hot spots in the engine. It sounded good to me so I'll pass it along here.

That was it. I cleaned up my tools and put them away and then took Lady out for a couple of miles so she could get the cooling system up to pressure. I drove back to Scott's, opened up the hood, and then checked the system for any signs of leaking.

I hope yours goes as well as mine did!

 

[94c2500]

This article originally appeared on Stu Olsen's website stu-offroad.com.

Parts Needed
You should always, always, always use an OE Mopar radiator when replacing your radiator. They will last longer than any radiator out there, guaranteed. Depending on whether you have a manual or an automatic transmission, you will need one of the following radiators:

55037652AA - OE Mopar Radiator (Manual Transmissions)
55037653AB - OE Mopar Radiator (Automatic Transmissions)

View attachment 503

The first task was to drain the radiator. The 4.0L cooling system holds a bit over 10 quarts. I put a bucket under the petcock on the radiator and cracked it open until a steady stream was running in to the bucket.

View attachment 504

While the radiator was draining. we pulled the rubber hose from the radiator's filler neck and then removed the coolant overflow bottle. The bottle sits in a couple of slots. Pull the bottle upwards to remove it from its mounting location. You will want to dump the contents into the bucket and rinse the bottle out. I had some fine sediment in the bottom of mine and certainly did not want to introduce it back into the system once everything was replaced and refilled.


View attachment 505

The fan shroud is held on with 4 bolts. Scott handed me a 3/8" air ratchet and it made pretty easy work of those bolts. While it could be done with a conventional ratchet, it was nice to use the air ratchet. Remove the two bolts located on each side of the fan shroud, near the top and bottom of the shroud.

View attachment 506

With the fan shroud bolts removed, you can push the fan shroud back towards the engine. By doing so, you will be able to make enough room to be able to remove the 6 bolts that hold the radiator in place.

View attachment 507

Here is a view of the driver's side of the radiator. You can see 2 of the 3 bolts (the closest one is a bit out of focus) that you need to remove in order to free the radiator. I found that the 3 bolts on the passenger side are best reached with a 3" socket extension.

Note: I got an e-mail from a Jeeper who had recently changed his radiator. He noted that the bottom two mounting bolts on his TJ's radiator did not have to be removed since the mounting holes were slotted. He as able to loosen them (without removing them) and then slide the radiator off of the bolts. You may want to check and see if yours is setup this way as it will save you some time.

View attachment 508

Remove the bottom and top hose (shown above) from the radiator. I was going to change out the hoses but after getting a chance to examine them closely, I decided to leave the factory hoses in place. I carry a spare upper and lower hose in the back of the Jeep so I am not too worried about it.

View attachment 509

With the radiator drained of coolant and the 6 mounting bolts removed, Scott lifts the old radiator out of the vehicle. You will need to wiggle the fan shroud a bit while you slide the radiator out. Although not a requirement, having a friend around when doing this part of the project sure does come in handy.

Since the cost is minimal, I picked up a new thermostat and a housing gasket. I had been carrying a new serpentine belt in my parts box for the last year. There were a few cracks in the original belt and I decided to swap the new belt in while I was doing this job. I'll keep the old belt in the parts box as a trail spare. I should comment that according to the factory service manual, small cracks running across the belt are not the "BAD" cracks you need to worry about. The cracks that run parallel to the grooves in the belt are NOT good cracks and you should replace your belt immediately;.

NOTE: If you are not replacing the thermostat or the serpentine belt, skip the following steps that detail the removal of both of these items.

View attachment 510

With the old radiator out of the way, I grabbed the air ratchet and started to remove the thermostat housing bolts. With one bolt removed, I decided it would be easier to remove the second one after removing the serpentine belt. Don't forget to unplug the electrical connector that is attached to the temperature sensor.


View attachment 511

To remove the serpentine belt, you need to loosen the bolt in the middle of the idler pulley. Mine was on pretty tight and I ended up standing on the bumper to get some adequate leverage with the ratchet handle. Once this bolt is loosened, you can loosen the idler adjustment bolt and put some slack in the belt. Be sure to note the routing of the belt around the pulleys. It can get a bit confusing when you put it all back together. If you don't have a diagram handy, be sure to draw one (just in case).


View attachment 512

With the belt removed, I took the second bolt out of the thermostat housing and carefully removed the housing. The gasket will most likely peal apart and leave some of itself on the housing and some on the engine block. Pull the heater hose off of the housing too. You can flush the heater core by removing the other heater hose where it attaches to the engine block and running a garden hose into the end of the hose you removed from the housing.

View attachment 513

Note the orientation of the thermostat so that you install the new one correctly. Remove the thermostat (it just sits in a recessed area on the block) and thoroughly clean the area of the old gasket material. Once the thermostat is removed, you can flush the block with a garden hose. Put the catch bucket under the lower radiator hose to catch the coolant coming from the block.

View attachment 514

After both the block and thermostat housing surfaces have been carefully cleaned, insert the new thermostat and position the new gasket. Place the thermostat housing over the gasket and tighten the housing bolts to 15 ft. lbs. Reattach the heater hose to the housing and if you removed it, the other heater hose going to the block.

If you removed the serpentine belt, now is the time to install it and adjust the idler pulley. I set the tension on mine as close as I could determine to the way the old belt was prior to removal.

View attachment 515

Here's a good tip I will pass along: Take a box knife and cut up the box that the radiator came in. Take a piece of cardboard and cut it to be the same width as the radiator. Push the fan shroud back as far as it will go and then slip the cardboard in front of the shroud. Now, when you slip the radiator into place, the shroud will not dig into the radiator core fins and bend them. Thanks Scott for the tip! It worked very nicely. Now, slip the radiator into position. This is another place where having a friend around will come in handy.

Note: Some distributors carry one radiator for both auto and manual transmission TJs. (cheaper to stock just one model that fits both) The radiator for an automatic has a pair of 3/8" fittings in the bottom of it where the automatic transmission fluid is routed through the bottom of the radiator to get cooled. If the new radiator that you purchase has a pair of fittings on the bottom, and you have a standard tranny, don't worry....get a couple of 3/8" plugs and screw them into the holes. This will keep "junk" out and just in case you should ever decide to get an automatic tranny, you'll already have the necessary radiator for it.

View attachment 516

After tightening the 6 mounting bolts and reinstalling the fan shroud (four bolts there), connect both the upper and lower radiator hoses. Give your handiwork a once over just to make sure you didn't miss anything (be sure the petcock on the bottom of the radiator is closed). I poured a full gallon of antifreeze into the radiator and followed it with a gallon of distilled water (well, almost a gallon....I put the last pint of it in the overflow bottle and then topped the bottle off, up to the cold mark, with antifreeze. Be sure to use distilled water. You do not want, nor need, the minerals from regular water plating out on the inside of your cooling system. (albeit, you will have some in your system if you flushed it with the garden hose as I did....well, we try the best we can!)

View attachment 517

After running the vehicle for about 5 minutes (with the radiator cap in place), I carefully opened the temp sensor. Scott said I should see some air bubbles when I did and sure enough, it burped a couple of times. He said this helps get the air out of the water jacket and prevents hot spots in the engine. It sounded good to me so I'll pass it along here.

That was it. I cleaned up my tools and put them away and then took Lady out for a couple of miles so she could get the cooling system up to pressure. I drove back to Scott's, opened up the hood, and then checked the system for any signs of leaking.

I hope yours goes as well as mine did!

FYI: CSF Radiator Company in California sells an excellent quality all-metal Three Row Copper-Core Brass Tanked Radiator for Jeep TJ, (and YJ). I installed one in my 2003 TJ several months ago while changing my water pump, and REALLY am glad I replaced the old single row/core plastic tanked radiator. I've seen numerous aluminum aftermarket jeep radiators, but this CSF Copper & Brass unit is vastly superior in construction in my opinion. Having three cores/rows instead of one increases cooling quite a lot, Fitment and quality control appear awesome. They're built as rugged as an old CJ factory radiator.
Their contact info and website link is below:

CSF, Inc.
9560 Buffalo Ave #150
Rancho Cucamonga, CA 91730

Phone: (800) 827-1991

Fax: (909) 355-2149

[email protected]


http://csfrace.com/product/jeep-racing-radiators/

 

[StG58]

Does it say where it's made? I'm curious!

I'll check the box and the radiator out tonight when I get home. It does have a big Mopar symbol on the lower tank though.

 

[Jerry Bransford]

Just so you know 94c, more rows do not necessarily mean better cooling or a better radiator. Absolutely. That is a far too common misconception.

For example, Jeep modified the TJ's original 2 row radiator to a different single row design in 2001 which improved the cooling. Both designs had all aluminum cores.

Most of the big expensive all aluminum radiators meant for desert use have just one large diameter row.

I wheel almost exclusively in the desert and pretty much all serious TJ wheelers out there know the oe radiator is more than up to any heat the desert can throw at it. Which is why we're so adamant about recommending newbies stick with the OE cooling system.

 

[94c2500]

Just so you know 94c, more rows do not necessarily mean better cooling or a better radiator. Absolutely. That is a far too common misconception.

For example, Jeep modified the TJ's original 2 row radiator to a different single row design in 2001 which improved the cooling. Both designs had all aluminum cores.

Most of the big expensive all aluminum radiators meant for desert use have just one large diameter row.

I wheel almost exclusively in the desert and pretty much all serious TJ wheelers out there know the oe radiator is more than up to any heat the desert can throw at it. Which is why we're so adamant about recommending newbies stick with the OE cooling system.

 

[94c2500]

I hear you and understand. That being said, I can tell from my own experience that this radiator is cooling my TJ better than the original radiator.
Thanks for the info.

 

[JP13]

I hear you and understand. That being said, I can tell from my own experience that this radiator is cooling my TJ better than the original radiator.
Thanks for the info.

What's the temp difference?