I have a 2005 Ford Expedition with A/C problems. I changed the accumulator/dryer with new hose, had a shop do a evaporator and install new freon. After 1 month its all gone hot...

You need to find out why the compressor is not working. If it is just low on freon, then add more freon. You can also use a a/c stop leak that could seal small leaks. If they say the accumulator is plugged, then have it flushed out. It takes special equipment to do that. I saw a picture of a car which had a generator hooked to the rear bumper with a window a/c unit in the rear window.

Against Ferderal Laws to discharge refrigerent into
the atmosphere

That is the may cause of holes up there

You can not install new freon without leak testing.
repairing leaks & pulling a vacuum with a pump
& knowing the theory of A/C Systems

Need a shop that is trained & has the proper equip

Yes, the black dryer, should have a blue or blake plastic cap you have to remove..

You tried to add refrigerant to the high side . How do you know it needs refrigerant ? You put to much in an it still won't cool . Why don't you take it to a qualified repair shop before you hurt yourself .

The AC is charged with R134 refrigerant through the low pressure side of the system, the charging port is on the Accumulator/Receiver Dryer, this is a round canister under the hood on the drivers side near the rear of the engine bay. Below is a picture of the Accumulator so you can ID it.

hi, the freon refill point you are looking for is on the accumulator. but you can't see it cause it's buried by the heater hoses, battery cables, and firewall mounted fuseblock. remove the fuse block cover, and get a bright flashlight, look just below the fuse block and you will see the cylindrical accumulator(aluminum canister looking) and the low side pressure port with the plastic cap on it.

FIND THE ALUMINUM ACCUMULATOR AND YOU FOLLOW THE LINES YOU WILL FIND IT

The low side port is on the side of the accumulator/dryer. The arrow is pointing to a hose connection, but to the right of that connection is the low side pressure port.

Find your evaporator canister which will be toward the firewall. The low port is hard to see. You will need to buy yourself a re-fill kit which comes with the freon and gauge. Warm the engine and turn air cond. on. Attach the hose to your low port. Attach the can to the hose and turn the needle to pierce the top of the can. Be sure to turn the valve needle slowly to release the freon into the system. If the can starts to frost over, wrap a warm cloth around can to get the freon to flow easier. The kit will come with a gauge which will tell you if the system is already overcharged with problems or if the system needs freon. The one I have has yellow, blue, green, and red. The yellow is low, blue is good but the system could still use more depending on the psi, green is overcharged, and red is over charged with system problems, or other system problem.

The accumulator is 17 years old, therefore it would be smart to replace it while the A/C compressor
is being replaced. There are no special steps for removal or replacement of the accumulator just
be sure all the fittings are tight.