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2008 Avalanche LTZ New Radiator Install

JohnnieMo

SM 2017
PM 2014
SM 2013
Full Member
Joined
Jun 2, 2011
Messages
905
Location
Calgary, Alberta
Okay, so I discovered a leak in my stock radiator around 170,000km.  You can read my analysis thread here:

http://www.chevyavalanchefanclub.com/cafcna/index.php/topic,151005.msg2147851.html#msg2147851

It was leaking right out of the front of the radiator and a stream of steam could be seen quite easily, along with a smell of antifreeze.  I was able to leave it for a little while and added some extra fluid, but it got to the point that the truck was steaming up the intersections, so it became time.  Here you can see the wet area on the rad:



So I decided to undertake a complete replacement.  At the suggestion of other members, I wanted to try a pressure test to confirm this was the only leak, however I was unable to rent, borrow, or steal one.  Buying one was $170 CAD, so I decided to chance this.  So on one Sunday afternoon a friend and I tackled a radiator swap on my 2008 Avalanche LTZ.  This would be a similar procedure for any GMT900 - Suburban, Tahoe, or Yukon from 2007 to 2013.

First step was to drain the radiator.  Unfortunately GM decided to remove the handy petcock valve and they make you remove the hoses.  We found the easiest way to access the lower hose was to remove the wheel and wheel liner and come in from the side.  In this picture looking from the inside, out, you can see how the hose is tucked up above the rail and is hard to reach:



The radiator, as it sits, will drain right on to the frame rail, then on to a piece of plastic - spreading the carnage on the greatest area possible.  Great job GM.  First remove the coolant reservoir cap.  Here is the hose detached and draining.  







I used a 5 gallon pail to collect this, and we got most of it.  Using the lift made this job a bit easier, but I would say that not having it wouldn't be a show stopper.

Next you start systematically remove the other hoses.  Start by first removing the plastic shroud above the radiator.  Pull off the entire top hose, the bottom hose, and then the two transmission lines, and the overflow line.  There is also a 6th line that goes to the engine block.  I have no idea what it is, but remove that too.  





Here is a picture of us removing the line on the engine.  It was a bit of a bear.  You need to use pliers to open the clamp and then slide it off.  Easier with a helper.



Next, mop up any mess and keep the dog from eating it.  You will have a nice slurry of coolant and transmission fluid.  I ended up pulling out about 9 liters, with likely a couple getting on the floor.  The truck says it has 16L in it.  So I think I got about 2/3.

Now remove the fan.  Two bolts on the top, and two electrical clips.  It pulls up and out fairly easily.  Now my truck has been supercharged so it's possible my air intake is smaller than standard.  I wouldn't be surprised if a stock truck needs to have the entire air intake removed to do this.  Mine didn't.



Here is what the backside of the radiator looks like:



Remove the radiator by removing the two bolts and pulling it up and out.  It will pee a bit when you do this.  When we got it out and inverted it, the water started pouring out where my steam leak was.  I guess it was a big hole!

Here are the replacement hoses I got from Auto Value:



And here is the new radiator.  It does have a petcock valve.  Cost was about $400 CAD for the radiator and hoses.  It is a Spectra Premium.



I decided while I was in here I would also replace the thermostat and ECT sensor.  The thermostat is held in with two 10mm bolts and is attached to the water pump on the engine right where the lower hose attaches.  Here is is with the old thermostat.



And here is the new thermostat with the grommet just getting installed:



Looking up from the bottom you can see where it gets installed.  Use a flathead screw driver and some emery cloth to clean up the two surfaces before reinstalling.  I found a torque setting suggestion of 17 ft-lbs.  



The ECT sensor is attached on the driver's side of the block just beside the first spark plug.  It has a little electrical clip on it.  Use a socket to remove and then thread in the new one.  This likely isn't necessary, but since I already had one, I put it in.  The two items from GM were about $150 CAD for the pair.





And here is a shot of the open engine bay



Next you install the fittings in the new radiator (it comes with those).  I have an aftermarket transmission cooler, so you'll notice I have a different fitting than most on the top passenger side.  The radiator slides into place and the rubber feet fit into little holes.  Two bolts on the top holds it all in.





Now put the fans back in.  Two bolts and two electrical connectors.  It also just locks in the bottom.



Now you could do the hoses before this step if you wanted to.  We chose to attach the bottom hose before installing the fan.  I think in retrospect we should have installed all the hoses (except the mystery hose).  It is a bit easier to manage.  Now install the top hose.  Here it is going to the engine.



And here it is installed.



Now fill the reservoir with 50/50 dexcool/distilled water.  I only got about 4 liters into the reservoir, so we decided to put some right into the radiator.  We used the hold hose and cut it off.



This got another 4L in there.  At this point we verified all the transmission lines (2), the upper and lower hoses, the overflow line and the mystery line.  All looks good.  We started the truck and got it up to operating temp.



Be sure to turn the heater on full.





My handy dryer vent proved very useful.



And that was it!  Added a bit more fluid as it burped itself.  Didn't need much.  I'll keep an eye on it.  I ended up adding about 11L of the 16L capacity.  Not too bad.  Not a complete flush, but better than nothing.  

 
Great write-up and pictures. Hopefully I won't have to do this.


What gauge setup do you have? I know it is in KM, but the style is very different.
 
blu_fuz said:
Great write-up and pictures. Hopefully I won't have to do this.


What gauge setup do you have? I know it is in KM, but the style is very different.

My truck is actually a US vehicle. Out of Indiana I think. When I imported it I added a new Speedo overlay from US Speedos. It is hard to find a metric overlay for these trucks but they had one. I don't remember what they called the style. You can get them in metric or miles.
 
(y)

thanks for the pics and right up.
 
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