The King - a 2002 GMC Yukon XL... 496 CI of STILL not an LS!

[ck80]

Well, I ordered a set of panels for the truck, I figure that worst case scenario they can go into the massive pile of spare parts if I decide to pick up a second truck instead.

Meanwhile, in the latest saga of replacing the missing tools, harbor freight got the a/c servicing kits back in stock after waiting for weeks and weeks.

Went this morning and picked up a new kit, a better vacuum pump, and 4 cans of 134a (assuming truck is empty its a 42 oz system) to be on the safe side. I'd rather have a $5 can left over than waste $15 in gas going back for more.

So a/c diagnosis and charging round one is about to go down. Time to see if the system is empty, or, just low and the computer nanny has activated the safety prevent on components from running. Then, assuming no bigger issues are present we'll run it and see if and where it leaks.

Need to do some more reading as well. I've seen references that say the pag 46 doesn't need addition if parts weren't swapped out and you're just charging, and others thay say the oil is somewhat aerosolized and if you did leak at all some escapes so add a small amount.

 

[Streetbu]

I know where the lines attach to the compressor is a common leak location in the north east with road salt. The aluminum block on the lines corrode and make the gasket fail.

 

[ck80]

I know where the lines attach to the compressor is a common leak location in the north east with road salt. The aluminum block on the lines corrode and make the gasket fail.

That bears looking into. For having averaged about 6k miles a year this truck certainly made its way around the country.

A couple years as far north as Michigan, west as Missouri, and southeast as Georgia, and a couple spots in between mainly in the mid south.

The underbody doesn't appear to have seen much if any salt time, but, you never know. It does, however, have dirt in the places that is known to accumulate, so I'd assume it's towed it's share of boats to the launch (explains the front hitch as well)

 

[ck80]

So today it was a nice cool morning with a good breeze, and Father's day dinner wasn't set to start cooking/grilling until 2pm.

Took advantage to do some a/c work. Whelp, coolant is low, but not gone. Low pressure side came in at 10# and the aluminum parts LOOKED nice, but that means nothing for the o-rings I guess.

The computer nanny appears to be preventing engagement of the compressor due to the low level, it's it's thing in these trucks or so I read.

Bought some extra UV dye because when I pulled out the cans of 134a I couldn't find the $5 can tap with valve. Same.dirtbag inlaw that walked off with the former gauge set probably took that with him as well... So, ran to the store, got that, and by the time we got home it was pretty warm out. Gave up for today.

So, tomorrow morning (thunderstorms permitting) I'm going to add a bit of UV dye to the charge port hose, connect the can tap behind it, then top it up to the factory levels... probably gonna need 3 cans or so worth. Then we will see how long it works for, and, should it stop working at least the UV light will show what and where the problem starts

 

[ck80]

So today it was a nice cool morning with a good breeze, and Father's day dinner wasn't set to start cooking/grilling until 2pm.

Took advantage to do some a/c work. Whelp, coolant is low, but not gone. Low pressure side came in at 10# and the aluminum parts LOOKED nice, but that means nothing for the o-rings I guess.

The computer nanny appears to be preventing engagement of the compressor due to the low level, it's it's thing in these trucks or so I read.

Bought some extra UV dye because when I pulled out the cans of 134a I couldn't find the $5 can tap with valve. Same.dirtbag inlaw that walked off with the former gauge set probably took that with him as well... So, ran to the store, got that, and by the time we got home it was pretty warm out. Gave up for today.

So, tomorrow morning (thunderstorms permitting) I'm going to add a bit of UV dye to the charge port hose, connect the can tap behind it, then top it up to the factory levels... probably gonna need 3 cans or so worth. Then we will see how long it works for, and, should it stop working at least the UV light will show what and where the problem starts

Ain't no foolin' we have coolin'!

It took a full can before the compressor tried to cycle at all, at which point it triggered the auto shutoff as pressure fell.

After a full 4 cans, we got just under 60# low side when cycling (as per manual spec) and about 180# high side (also as it should be - it's already about 90* out)

So, now we wait and see if it keeps working... or, if it leaks down fairly quick. Added about 1/4oz of UV dye so here goes.....

 

[Streetbu]

You can cheat the system by jumping the low pressure switch while filling the system and get the compressor to engage. Helps sometimes.

 

[ck80]

You can cheat the system by jumping the low pressure switch while filling the system and get the compressor to engage. Helps sometimes.

Thanks for the tip... hard to believe but this was my first foray into vehicle a/c recharge, only took 5 different decades where I've been messing with cars to get there. Ive measured pressures to diagnose before, but never did an automotive system... I guess mostly same principle applies as other though. Only reason I decided to tackle it is because it's a 134a system which means refrigerant is cheap and plentiful if I miss something.

My older vehicles all still run r12, and that stuff is so expensive now it's cheaper to just pay a small town garage to do it for me, recycle the r12 and all. Usually I'd try to figure out what it should need ahead of time to keep em honest.

The other newer cars never had an issue, yet, but I figure someday they may so might as well learn. I'll also be stocking up on cases of the 134a when the time comes before its regulated away too. Still have canisters of r12 on the shelf, liquid gold, that I just give the garage after we verify what a car needs.... if it needs.

 

[fleming442]

Thanks for the inspiration. I put all new AC stuff in the Pig a while back, and it's been hotter than 2 rats fvckin in a wool sock round here. So, I took my 15 minute break from work, and threw the vacuum pump on for a while before slamming some refrigerant in.

EDIT: Yeah, that ain't work so good. Got a leak on the high pressure line at the bottom of the condensor (probably the most difficult thing to get to in the whole system). Oh well, back to sweating.

 

[ck80]

Been thinking it over a while and finally decided to go with my initial take on a name for this beast... title updated.

We will be calling it... The King.

Based on coming from Memphis, the selling dealer being within 5 miles or so of Graceland, and, the status of its factory produced 8.1L 496 inch engine, it seems appropriate.

 

[L92 OLDS]

You might be interested in this. Maybe you’ve already seen it? He plans on building the bottom end and turning up the boost.