JohnHere wrote: Sat Nov 15, 2025 10:45 pm
I wonder why GM would apply it to the accumulator, a part that would normally be replaced every time the system is opened for whatever reason (and the decal lost after the first replacement).
I left the system under a light nitrogen charge as I had to leave town for few days, I will charge it when I get back home. I've got a 2000 3500 Silverado Dually crew cab which was my father's also, which I'm driving back to Phoenix this week, which will be next in line for some AC tune up. My dad bought this truck new and it has 56k miles. It has the same circle sticker (different specs) on the accumulator and the same piece of shit HT6.
I'll take some accurate temps and pressures so we can discuss.
I'm not sure. I turned it on and it appeared to be short cycling but it was pretty cold. I unplugged the compressor for my journey as I would need the defrost and didn't want to run the compressor with an unknown charge or condition. Didn't want any issues in that regard.
I did break down in Raton New Mexico. Truck died in the Subway sandwich parking lot. Would crank but wouldn't start. Luckily I brought my scanner with me. Crank position sensor. I walked to Oriely's and bought some tools and the sensor and was back in business. I called three shops and asked if they could send a mechanic to pick up the part and come by and install it and all three said no. "They didn't do that kind of thing". I said I would pay triple the rate and they declined.
Im going to pull the lower fan shroud in that 99 Yukon and change out the lower rad hose. Looks tired and original. So maybe a few days before I charge up the Yukon.
Hey guys, sorry for the long delay in getting back to this post. Work, family, holidays, etc. Before I wanted to test the system I wanted to verify that no mice had gotten into the HVAC system. So I pulled blower motor and inspected what I could see with a mirror the evap and then vacuumed out years of minced leaves and debris.. I pulled the front dash off as well as the lower valance. I used a leaf blower and moved the modes to blow every duct clean, or at least verify a pile of nesting material didn't come out. I then used AC forming cleaner to fill the duct work, up the evap drain hose, in the blower motor opening etc. let sit and towels placed at the floor accepted the drippings. Installed the blower motor hooked up a battery charger and let the motor run while I put the dash back together. I also had to replace the blinker combo switch while I was in there.
Today I purged the system of the nitrogen head I left in there, vacuumed it down for an hour and charged with 44.2 oz. Here are the numbers and specs.
Clutch fan - New GM OEM.
Condenser - OEM 1" thick, no fin damage, looks new.
Orifice tune - Cleaned and reused original, installed in Y pipe to front only.
Compressor - Sanden New.
Rear - untouched, OEM as far as I know, now receiving liquid refrigerant.
Temp in my garage 77*F, engine idle, windows open, max AC with recirc on fan high / rear AC on high fan
Charged with 44.2 oz 134A as a gas. (Took a while).
Wasn't too hot today, and evening is here so a true HOT load test will have to be done latter.
Engine RPM IDLE.
high side = 135 psi.
low side = 28 psi.
front vent (middle of dash) discharge = 39.5*F
Irear (overhead only) discharge = 42*F
2000 RPM (equal time off and on cycle)
High side = 163
Low Side = 19
Front vent = 38*F
Rear vent = 43*F
