The time is almost near to start installing all the new ac components in Brutus. Everything is brand new with the exception of the evaperator. The evaperator is about 20 years old, it was purchased new, but never used, it sat in our dusty shop for years. Should i flush this evaperator our or just buy a new one?
Nick and George
1986 1/2 F150 XLT Lariat 4X2 4.9 - C6 - 3:08 in a 8.8 - Fully Loaded
Owned since new
Flush it out. The parts stores have the stuff for flushing. I'm told that some have it in spray cans w/a fitting to go to the part or hose. But mine has it in pints or gallons. I bought an pint first and it wasn't enough for everything and then bought a gallon.
I poured it in and then rotated the part many different ways to ensure the liquid got to all parts, and then hit it with compressed air. A few rounds of that and everything came out nice and clean.
No, the drier has a desiccant in it that absorbs moisture so has to be kept capped. But the evaporator and condenser are just tubing with fins welded to it. So you flush it out and then it would be good to cap them just to keep any bugs or dust out of them.
What I did was to flush everything but the drier, and then cap them. Once I had the truck where I could add them I did and connected them all via the hoses. So the system is sorta "tight", but I still need to replace the drier and all of the o-rings, pull a vacuum, and then charge it.
I had to replace the condenser, the PO bent it and closed some tubes.
Went with the newer type used junk yard compressor.
Because of the newer type compressor I had to go for new type hoses on the compressor.
New dryer, orifice valve and psi switch on the dryer.
I flushed out the Evap that had been open for about 4 years.
Like Gary I kept the dryer sealed to the vary last min. and was the last thing to get installed.
Because most of my system was new, read no oil in system, I had to add oil to each part.
Installed dryer after adding oil and then pulled a vacuum and let it sit for an hour or more.
Once I knew the system held vacuum I pulled more vacuum for about 2 hours to make sure everything was pulled out. Moisture will boil out under a vacuum and why you want to pull for a long time if you can.
Now this is where it get tricky.
At first what I seen posted it should have taken little less than 3 - 12oz cans of Freon.
Well it only blew cool not cold and the low side pressure was low.
I had to add another 2 - 12oz cans for a total of 5 - 12oz cans to get the low side psi up to what the charts say and it is blowing cold.
I have a post "rebuilding AC system" or something close.