What did you do to your NBS GMT800 Tahoe/Yukon Today?

[ncalvo]

I tried my hand at fine tuning the A/C charge now that temps have approached 90 degrees here in Texas. I can't seem to figure out the best way to gauge how much refrigerant I should add (I know, I should be measuring by weight but we're long past that unless I want to evacuate, vaccum, and recharge from scratch which I'd like to avoid). Should the fan be blowing on high, or on low when I'm reading pressures? Should I have a shop fan blowing across the condenser, or spraying with a hose, or leave it completely alone and let the vehicle pull air across it, unassisted?

I can't seem to get it much colder than 50 degrees from the vent with ambient temps around 75 and humidity around 70%. I think the old girl is capable of better cooling, but maybe based on her age it's time for a new condenser since I'm sure after a quarter million miles, the OEM is likely not as efficient as it used to be.

Maybe this will help you if you haven't peaked inside at your evaporator. Try cleaning it up, the gunk and growth and fouling could severely restrict the heat exchange. Then grab some evap foaming cleaner.

03 Tahoe Cabin Air Filter Retrofit + Clean Evap

Last september I replaced my ac compressor, all easily accessible hoses and lines, the orifice, dryer, sensors, pulley, belt and clutch fan. System was working well through the mild florida winter. Spring comes around and continues to get hot and humid and I easily can tell my system is not...

www.tahoeyukonforum.com

I do not think changing your condenser will help but I could be wrong. The way I charge my AC is just with a low side gauge/can, front and rear ac on full blast while parked.

 

[Keviebear86]

Since we are on the subject of AC work, how many people have tackled replacing the rear evaporator core and lines? I just ordered a kit from autocoolingsolutions.com and I want to know if its a one day job or am I breaking out the top shelf whisky and spending a weekend in the garage?

 

[RAMurphy]

@Rocket Man tackled some significant AC work back there. Pretty involved. It's in his build thread.

 

[Sam Harris]

Since we are on the subject of AC work, how many people have tackled replacing the rear evaporator core and lines? I just ordered a kit from autocoolingsolutions.com and I want to know if its a one day job or am I breaking out the top shelf whisky and spending a weekend in the garage?

Seems like a royal PITA. I’ve previously taken the rear clamshell apart, to replace a flapper, but the numerous parts inside all came out of alignment, causing it to be impossible to reassemble while in the vehicle. I later purchased a new clamshell assembly, to make my life easier, but it’s sitting in a box untouched. Not an enjoyable job… I may even buy the block off plate and be done with it.. we will see. Having these new puppies, I’ll probably want the rear A/C fully functional.

 

[Keviebear86]

Seems like a royal PITA. I’ve previously taken the rear clamshell apart, to replace a flapper, but the numerous parts inside all came out of alignment, causing it to be impossible to reassemble while in the vehicle. I later purchased a new clamshell assembly, to make my life easier, but it’s sitting in a box untouched. Not an enjoyable job… I may even buy the block off plate and be done with it.. we will see. Having these new puppies, I’ll probably want the rear A/C fully functional.

The Mrs. wants the kids to be comfortable on long road trips. Thinking that might be the deciding factor for me. I believe I have the know how to do it, hopefully it doesn't "hurt locker" me.

 

[latvius]

I've done it, its not that bad. The EASIEST way is to take the whole assy out then take the shell apart. I took the top part off of the shell while it was in and it was a real PITA trying to get to all the clamps that hold the two shell pieces together. You will have to disconnect the A/C lines as well and you will need to vacuum and put in the freon after. If it was me doing it I would buy a new clamshell as it comes with a new blend door. I also am in the South so I had no problems with rusted together parts.

 

[Rocket Man]

Since we are on the subject of AC work, how many people have tackled replacing the rear evaporator core and lines? I just ordered a kit from autocoolingsolutions.com and I want to know if its a one day job or am I breaking out the top shelf whisky and spending a weekend in the garage?

I did it on my 02 recently. One thing I found out is even here in the PNW where we don’t use salt on the roads, there’s no way those rear AC lines will come off. Mine were seized onto the evaporator core. Plan on breaking or cutting them off. Also, the quick connects for the heater lines- you won’t find OEM ones and they’re 90* angles. I ended up buying Dorman ones. The lines themselves are fairly easy. I cut the old ones out in pieces, and the flex lines went right back into the same clips that held the old ones. I know they say you can just tie strap the new onto the old, but nah. Here’s a link to the place in my build thread where I decided to not block the rear off and replace the parts instead. You’ll want the expansion valve also.
Edit: and yes, remove the rear assembly completely to replace the parts inside.

Rocket Man's 02 Denali Build Thread AKA "THE BEAST"

I got a couple parts in, still waiting on the line. The block off plate seems ok, could fit better but I think the main problem is the seals they included. They’re about twice as thick as the factory ones and when I installed the high pressure side and torqued it to spec it looked crooked...

www.tahoeyukonforum.com

 

[Keviebear86]

So now the next question is...To remove the factory fender flares or not? After fixing all the rust and the body looks much better, I'm questioning keeping the textured fender flares.

 

[Sam Harris]

So now the next question is...To remove the factory fender flares or not? After fixing all the rust and the body looks much better, I'm questioning keeping the textured fender flares.

Hard to offer an opinion without pics..

 

[mwilson62000]

GMT900. Ordered all ACDelco parts for 2008 Yukon XL from Rockauto today.

Parts starting to arrive!