14 Sierra, hvac blowing heat, water dripping from exp valve

[wessidedabesside]

Ac started slowly getting warm, some days it would blow cool, at night it would blow cool and it finally just started blowing warm..

 

Tried a shot of ac pro but noticed the dial would not move, it would go down when i pulled the trigger so i stopped and knew something was weird.

 

Compressor spins and engages, it only clicks once when the truck is started up but never cycles on and off.

 

Bought a manifold guage and vacuum set to try my hand at diy with this truck and my other vehicles.  Hooked it all up, and noticed on startup ac blew cool and water dripping from the firewall hose but immediately went hot and stopped dripping.. then noticed water bubbling and dripping from the right side of the exp valve.. so the evap core went hot and dry but the exp valve block remained cold and started dripping water..

 

90 degrees out and guages were reading 25psi low side, and like 125 high side.  I connected a can of r134 and the system wasnt drawing in any freon the sight glass was clean..  could this be an expansion valve issue?  Im thinking about evacuating the freon and pull a vacuum to see what happens.  I cleaned the cabin filter and used a camera to look at the evap core in the dash its not clogged or nasty. Both cooling fans are running and i had a fan blowing at the grill.  I also checked all fuses and relay relating to ac.

[wessidedabesside]

does anyone know if i have to buy a snapon or similar scan tool to read hvac codes on these vehicles?

ive been using hp tuners to read codes from this truck and wasnt sure if..  i dont have dtc codes, or if it cant read hvac module codes..  also, do the autozone readers give hvac module codes?

 

im in the process now of replacing the expansion valve, but curious if i should go ahead and replace the pressure switches, where ever they are. (any pics of hints of where these are because internet searching gives me nothing)

[ohed]

The Pressures  you recorded are too low  for R134

[wessidedabesside]

So i did a full evacuate, replaced expansion valve, vacuum and recharge.. did all according to ambient temp and the high/low chart, fan blowing on condenser, the whole nine yards.. leak down showed no change after vacuum, a seal on the old exp valve looked gnarled up missing the black rubbery gasket portion.. dye was injected too so i got that to monitor in the coming months.. so far temp guage on dash vent is showing 45-50F.. its very cold for sure.. i'll see if it gets me through this month and a florida trip..  i swabbed the inside of the lines and theres a black oily residue, no sludge buildup on the expansion valve it was very clean..  just a black residue if you wipe hard enough you can get.. so the system could be ruined or compressor is done for..  we'll see.

[richard wysong]

If you suspect the compressor is failing I would replace it before it grenades. Right now a system flush may remove some of the residue, After a internal failure of the compressor you will be replacing 80% of the system as no amount of flushing will remove the debris from the system