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How To: Radiator Stack Removal and Install

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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.
 

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#123 ·
Well my shroud came in yesterday, and I took the laborious 5 min to install it. Haven't driven the truck since then to test it out. Sometimes it will sit a whole week before being started. I only drive it when I need to.

Sure does look a WHOLE lot different under that hood now, though.
 
#124 ·
#127 ·
#128 ·
You will notice a difference in how much cooler it will run
 
#129 ·
WOW dude looks like you live on or run a chicken ranch. Man that sucker was packed. Your truck can now breath some cool air, and refresh with cool (relatively speaking) water.
 
#130 ·
Haha, that's what's 350,000 Kms of build up looks like. And I live in Calgary! Just putting it back together now, should be interesting to see the difference.


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#131 ·
I did my 08 dmax (215K) a couple of weeks ago and it looked like that too. Temps stayed the same (210 pulling my camper), but now the AC cools at idle and pressures returned to normal. I was changing the hoses while in there, so pulling the radiator was easier than removing the intercooler. Now, whenever the temp creeps over 210, the fan clutch engages and cools it right back down.

Now, if only they can replace my recalled passengers side air bag, I might go camping with the wife again.
 
#132 ·
My temps remained the same. I run 210 on the factory gauge all the time. I wouldn't think the previous owner would have installed higher temp thermostats, maybe my gauge is wrong. at least my fan clutch isn't running most of the time now. I was hoping to get a mileage increase with the clutch not engaging as much, but it remained the same, 12 combined driving empty and 10-11 pulling my 8,000 lb. camper
 
#136 ·
From everything I have learned with these trucks, oversize tires, lifted trucks, and speed are the biggest reasons for poor mileage.

When I got mine, it had 265/75-16's on it, and stock is 245/75-16. Most likely I will got back to stock size next time. Although I am getting pretty decent numbers on mine. 13 city, 18, combined, and 20-21 highway, 90hp daily driver/econ tune. I get 12+ pulling my 12K 35ft 5er, heavy tow tune, EFI. Tow/Haul mode always on when hooked up.

Prior to EFI I was getting 15 combined and 18 hwy, empty. Same tires.
 
#133 ·
My biggest problem was my tranny temps, they get fairly high when I'm in stop and go traffic. Especially since I've had my tranny built. This will help hopefully.


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#137 ·
I have a 2006 K2500HD, I installed a Banks Power Pack Kit ( which has a replacement larger all aluminum intercooler, to handle the boost increase) @ 75,000 miles, wasn't as dirty as most pics, mostly dead bugs. Still cleaned radiator & A/C condenser (since everything was accessible).Also put a window screen in front of all coolers (behind the grille) using the upper close out panel as a fasting point, wire ties @ the bottom. Since doing this I've noticed that the screen I installed catches a high percentage of bugs and debris & is easily cleaned with the hose when washing my truck. If your doing this procedure, it's a good time to add the screen. Also noticed there has been no change in engine temp (even with the programmer turned up) or A/C. FYI
 
#138 · (Edited)
I will say that I had a noticeable chance in temps! My air wasnt working at idle. Would overheat on long grades! All of that was "fixed" after cleaning the stack! This picture is of me pulling my 30ft travel trailer at 70mph on a mid 70's degree day.
 

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#144 ·
Some one questioned the accuracy of the factory gauges on another site, over the past 2 weeks I have been randomly comparing the gauges against what my EFI V2 shows. Scared me how accurate they were, Ben at BTDieselworks post quite a bit on DD and a member here (duratothemax) has stated the same about the gauges and sensors.

The only problem some may encounter is what position the needle is placed on the stepper motor in reference to the numbers on the face plate. The one most confusing was the ECT, at startup it was way off, at operating temperature within +/- 5 degrees, the remaining were damn close...
 
#145 ·
Thought I recalled Mike saying the Trans temp gauge was spot on accurate, no?
 
#150 ·
Great write up there Nate. took me about 5hrs, (margarita break with the wife), but my radiator was caaaaaaked up bad. used to cruise on my 40 mile commute at about 200-210 now I never get over 185. Towing this weekend should be an eye opener!
 
#151 ·
Seems like a ton of work to clean some gunk out of the radiator...I guess it would be better if you already have the truck taken apart for something else.
 
#158 · (Edited)
Feeling pretty darn justified here. Last weekend took the family over Stevens Pass in the WA cascades for a little camping trip outside of Leavenworth. The last two times I had towed over Stevens, I damn near overheated the first time and did overheat the second time, actually setting off warning chimes etc before I crested and it started cooling down again. This trip was completely different post stack cleaning.

AC cranked, 55-65mph over the whole pass, even a short burst at 70mph where I passed an old ford motorhome, trans never got over 200 and water never breached 210. Flat towing before and after the pass ranged from 185-195 avg and it was 103 ambient temp on the east side of the pass. Glad I didn't just swap out thermostats; I would have just overheated again. totally worth the work IMHO.

Thanks again Nate!

Edit: AC now ice cold at idle as well, whereas before it was going to room temp when stopped.
 
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#152 ·
I don't know that post 07.5 even need to worry about this as much as the earlier vehicles, but I can assure you I felt the same way until I saw what I was working towards. couldn't get the camera in for a pick that did it justice, but let's just say that using an electric pressure washer with a gutter wand holding in one spot took about 10 seconds before the water broke through the caked on filth and started blowing out the other side. I overheated twice pulling up Stevens pass, 4k elevation w/ about 3.5+4% grade doing 50mph w/ a 29ft wildwood 5500lbs loaded in 90deg temps. cleaning the stack is the ONLY thing I have done to mitigate this, so I will update w/ results this weekend post cleaning to add some value to the work.
 
#153 ·
I hope you are right, because this is not something I want to have to do later. Similarly, I'm glad I don't have to worry about my lift pump in my transfer case like the older models do. I seem to have made a good decision to buy the truck I have rather than the 07 I was looking at.
 
#155 ·
I hear ya. Had an LMM right when the economy took a nose dive. my first new vehicle ever and had to sell it a year and a half later. now I'm dealing w/ an 03 w/ 240miles on it, originally an OH truck so plenty of rust to scrape, convert, undercoat etc. the newer trucks are nice, but I don't miss the EGR or the DPF at all.