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How To: Radiator Stack Removal and Install

183K views 235 replies 63 participants last post by  PSCMIKE  
#1 · (Edited)
ok since this has not been done before or if it has it has been hidden in the millions of threads on this forum, I went ahead and decided to take some pics of how to remove, clean and install the radiator stack. this should pertain to all OBS trucks since I have an LBZ and it is generally the same for the LLY and LB7.

Symptoms:
1. truck is running a little hot.
2. transmission is running a little hot.
3. A/C is not quite as cold as it was before. (should be done before this http://www.duramaxforum.com/forum/diy-tech-discussion/136547-how-clean-evap-coil.html )
4. truck is operated in dirty/dusty generally nasty conditions.
5. you have changed out the thermostats and have done a complete DEX-cool flush but engine is still running kind of hot.

now this is not a cure all for some of these conditions, because maybe you need to change fluids, maybe something else is going on to cause the issues, etc. this is a how to for removal and reinstall of the coolant stack whether just cleaning them like I did or having to replace them for what ever reason. it is a good service to add to your yearly maintenance routine as well.

so lets start with what you will need to accomplish this project.

before you begin:

1. you need to get you some engine cleaner/degreaser
2. get a good pressure washer. one that will easily remove the garbage that has collected on your coolant stack but not so powerful. you have to remember that you will be spraying it on the fins of the radiators and around electronic equipment.
3. make sure that you have you plenty of good hydration beverage, like me I had me some Gatorade and water because I was out in the TX. sun during the middle of the day.
4. below is a list of tools that you will need to accomplish this mission
5. if I have forgotten something them by all means make sure that you acquire it before you start this project.
6. MAKE SURE YOU HAVE AT LEAST 4 HOURS FOR THIS, 1.5 FOR REMOVAL AND 1.5 FOR REASSEMBLE, AND 1 HOUR AS A BUFFER/BOO BOO LIP COOL DOWN TIME :rofl

list of tools needed

1. body clip removal tool
2. long needle nose pliars and a magnetic retrieving tool (to retrieve something if you drop it)
3. socket wrench with a couple extensions and a swivel joint. (I used 1/4" drive because none of the bolts were that big or tight that constituted anything above 3/8" drive.)
4. sockets in these sizes 10mm, 7/16", 1/2"
5. a T25 TORX head (bit/screw driver/wrench whatever you choose) there are only 4 bolts/screws that you will have to remove with this.
6. you can add a good flat tip screw driver and channel locks to the list.
 

Attachments

#154 ·
Not to take anything away from the outstanding instruction that Nate has provided in this thread! I just hope it is something that I never have to worry about. If I do, I will be sure to use this.
 
#156 ·
I don't miss my EGR or DPF either! LOL
 
#163 ·
Coin op car wash buddy :thumb My temps are good after cleaning the stack.
 
#162 ·
#161 ·
I need to do mine over but drain coolant and get the radiator out and clean it with a pressure washer and coil cleaner. Also need to clean the inside of my intercooler but my ac is cold as ice now...so amazing
 
#164 ·
Be very careful with a pressure washer on your cooling stack. Use a good de-greaser, let it sit a while, then use a garden hose from the back side. No hi pressure stuff. Water volume is king here.
 
#165 ·
its been almost 2 years to the day since I did mine and made this DIY thread. I tore into mine yesterday because I was bored and didn't really have anything to do because (I just really didn't feel like flushing my hydoboost to be honest.) the stack was still pretty clean, but just to be sure I pulled out the little electric pressure washer and soaked the stack in some of this

https://www.google.com/?gws_rd=ssl#q=fast+505+degreaser

I have used this stuff on some smoke eaters at my VFW and ill be darned if they don't look factory new when soaked for a few minutes and sprayed with a regular garden hose. so now I know I will be for another 2+ years.
 
#171 · (Edited)
Just an addition to this post, secure the panel in the oval highlighted to the bumper while doing the stack clean, mine was flipping up while driving on the highway and blocking air flow through the lower bumper slots to the transmission cooler on the 2006. Easy to check just lift it with your finger.
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Attachments

#172 ·
Don't remember having that on mine
 
#175 · (Edited)
I think it had some plastic or metal clips at some point.

I just drilled (2) 1/4" holes and used some big fender washers, nuts, bolts, lock washers, kissed the bumper right on the chrome and with one hand/arm around the top and one arm/hand around the bottom and managed to bolt it together. If you come up with a better way post it....

There is a better way, the clips that were installed at the factory, found the clips in an earlier post, you can barely see them..
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Image

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#179 ·
Yes?
 
#180 ·
Update, after cleaning the stack the truck runs wayyyy cooler. The fan never even kicked on through the mountains at 34 degrees Celsius for a 7 hour drive.


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#183 ·
Lol and not everyone spells it correctly! Thats why I was wondering
 
#185 ·
#187 ·
#188 ·
Great write up! Did this on Saturday, took a few hours and only had two small bolts left over. Not sure where they go but doesn't drive any different, yet....

Didn't lower my temps that I can notice. Usually hits 190-195 at freeway speeds but I haven't drove on the freeway yet. On my test run of about 10 miles or so it did read 190 once on the CTS, don't know if that's because of all the water that was left or not?
 
#189 ·
Great write up and looking to tear into mine this Saturday. Thanks to c20elephant I was directed to this topic from another forum after searching for answers.

Quick question about fluids, I didn't see where the fluids were drained. Do I need to drain any fluids to do this cleaning? Since I have never cleaned the stack would it make sense to pull the radiator for ease of cleaning?

All symptoms are pointing to this cleaning and really hope this resolves the overheating issues I've had. I've had the coolant flushed, changed the t-stats and temp sensor over Memorial Weekend with the same overheating results when towing. I live in Mesa AZ and temps are 110-115 right now. Even in the winter months I was having issues. I currently have 188k on the truck and heading to Colorado in the next few weeks towing a toy hauler so I'm looking to get this resolved.
 
#191 ·
If you don't disconnect the hoses, you don't have to add any fluid.
 
#192 ·
If you remove the intercooler only, no fluids have to be drained. However, in my situation, it was much easier to remove both the radiator and intercooler as a unit, therefore requiring removal of the antifreeze. There is not much room for removing the bolts holding the radiator and intercooler together, and you risk damaging either unit in the process. I also wanted to replace the hoses and flush the cooling system, so it really was a no brainer in my case. Other than being heavy, it was much easier this way for me.

I didn't see a big improvement in temperatures after cleaning the stack. and mine was really stopped up after 200K miles. I run 210 when towing my camper still, but now I never hear my fan clutch engage like I did before and the AC cools well at low temperatures. Before cleaning, my clutch cycled on about 50% of the time, and my AC blew warm air at idle and the high pressure was almost off the gauge. Trans temp did go down about 20 degrees to about 205 when towing in the hottest part of the summer, though.

Also, 10 hours is about right for this procedure, I did it by myself, other than removing the stack, and I don't really see a big improvement with additional hands. Oh yes, those instructions were excellent, follow them and you won't have any problems.