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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

#95 ·
Bravo!!!!
 
#96 ·
Thanks for the excellent write-up. How similar will this procedure be for my 08 LMM? I am having all the classic symptoms of low air flow and am just waiting for it to cool down into the high 80's to undertake this.

Again, excellent write-up! Thanks for taking the time to document this for all us newbies!
 
#97 ·
Looking forward to doing mine in the winter. My trans is running about 80-85 above ambient. Sixty would be better. Tested mine these last 2 days hauling the 5er to Oregon in 100+ temps. My truck fared better than my trailer tires. :(
 
#98 ·
My LMM I paid to have the radiator cleaned. The truck is different than your classics. Basically didn't bother removing front AC and Intercooler. The radiator removes from back after Fan is removed. Much easier to clean intercooler from rear after radiator is removed.
I was topping 240 pulling uphill before cleaning. Now truck rarely tops 200.
 
#99 ·
Well worth the investment!
 
#101 ·
So I think I am finally getting around to doing mine tomorrow. Will let ya know if anything odd happens.

Can the intercooler and radiator be separated any while still in the truck? Seems like it might be real difficult to clean between the two? I doubt I can pull the both of them myself, and extra hands are not available.
 
#102 ·
I tried to separate mine in the truck and had issues . I broke stuff. I'd recommend getting everything on hooked you get this packed ready to come out can have a friend come help you just lift it would be a lot easier
 
#104 ·
Before you get them wet try with air to blow out most of the dirt from the back side
 
#105 ·
I lifted both out together but got my wife to help with the reinstall. Mine were so filled with grass seed that a pressure washer was required. Then dried over night and then more air.
 
#107 ·
IIRC, about 5 gallons
 
#109 ·
OK got it done, in one day no less. I would estimate a 15-20% blockage. Probably closer to the 15. However something came to mind when re-assembling. I noticed in the OP's EXCELLENT write up that he mentioned removing the cover from the hood latch. ????? I don't have one. BING! I have 8 of those push pins that hold NOTHING. Is there supposed to be a shroud that goes from the grill to the top of the radiator? If so I do not, nor have I ever had one.

That alone I suspect will cause enough air bypassing the radiator to be a issue.

Can anyone recommend a source for the hood latch cover? Is this a shroud that goes full width of the radiator?
 
#110 ·
While I was in there I also replaced to epoxied up windshield washer pump motor. I was tempted not to since the epoxy jug worked and held up nicely, but I had already bought it so I went ahead and did it. I kept the old one just in case.

It wasn't too bad to get to. A little tight, but didn't have to take out the battery or remove the tank. It is sitting behind the horn in this pic. It is the blue connector on the left, again, behind the horn.

Image


Also, this sensor (impact sensor?) that sits on the transmission cooler frame, broke, at least one of the tabs that snap it into place did. I zip tied it back on. Anyone know what it is?

Image


MANY kudo's to the OP fro this write up. The excellent pics and write up really helped me get over my temporary panic, when trying to remember where all those bolts went.

I didn't pull the radiator/intercooler combo, since I was able to get in between them sufficiently to clean.

I rigged up a high pressure line to blow all coolers out first, and then I used (since I do not own a pressure washer) a pipe that is for cleaning out RV holding tanks. It's a piece of PVC pipe with a shut off valve, and the end capped. The cap has a 1/4" hole in it and I connected it to a farm bib hose connection at my house. It's running about 65PSI at that point. It would spray a 1/4" water line about 40ft. It boiled water through those coils.

I cleaned, soaped and cleaned again, and then blew as much water out of them as I could. I was amazed how much water was STILL pulled out of them when I restarted the truck.

Also, I found a link. Is the part I am referring to called the Upper Panel?
GMC Part - 15809933 | UPPER PANEL
 
#111 ·
Thats the part. That could give you a little issue. Not having it in.
 
#113 ·
Hate to get off topic but quick question. My mirror no longer shows temp or direction. Is it the mirror or sensoe that would cause this?
 
#114 ·
OK gonna order the part now. Don't think I will worry about a new sensor. It's not going anywhere as it is. Interesting place to put it though. Seems like when you're parked, it would be affected a lot by radiant heat from the engine and radiator.
 
#115 · (Edited)
that would be the temp sensor that shows on your mirror inside of the truck. its not really affected by the ambient temp that much, because the system pulls the air not pushes it.

if your mirror is not showing anything, you may have blown a fuse.

thank you for the kind words about the write up, and I hope the truck is running better for you know.
 
#116 ·
Nate, I was referring to the vehicle sitting, after a drive. The heat from the engine compartment would affect it, until you started driving again.

You are welcome.

I ordered the shroud, upper radiator support, or what ever they call it. I will have that on before my next RV pull, and will know more then, but it can inly help. It wasn't overheating, but seemed a little warmer than it should have been.
 
#117 ·
Do you have to take the radiator out? Or just the intercooler and swing the cobdenser out of the way?
 
#118 ·
The intercooler and radiator are bolted together much easier to take them out together
 
#119 · (Edited)
There is a YouTube video on replacing the intercooler I believe or maybe radiator either or that video will show you what you have to do also
 
#121 ·
775,000
 
#122 ·
When I cleaned mine I did not have (nor want) to remove the radiator/intercooler. I managed to get a rigid air line with a 90 deg at the end and blow most of the crap out, then I did a similar thing with a water hose. A 1/2" PVC pipe with a cap glued on the end and a 1/4" hole drilled in one side of the cap. The other end has a garden hose connector with a ball valve on it. That will put out a lot of pressure in a small area and should do the trick. It flooded out the other sides of mine.

When done, I blew it back out with the air hose, and was still shocked to see how much water came out when I started the engine.

Mine still runs right at 190-195 empty, so I am hoping the upper radiator shroud will help some. If not, I know what has been maintained anyway.