A/C evaporator valve screen

If there is a screen in your expansion valve it will be in the small end of the valve.It will be cone shaped and look like it would fit over the lead end of a #2 pencil.It might have a collar attached to it that you could a EZ out to wedge into and twist it out.Is that a RHD car you are working on ? does the heater box look like one from a LHD car? PS dont turn the hex key looking thing

Evidently then the screen was removed at some point.

The car (US model LHD #6799) is getting a R134a conversion with a new front mounted condenser, hoses, R-D and rotary pump. The evaporator valve and the evaporator itself are the only components being reused.

Considering that, two more questions:

1. What is the appropriate solvent to flush the existing evaporator core and valve to clear out the old R12 oil?

2. Should I create a new screen? Thinking maybe a reshaped SS faucet aerator screen?

quote:

Originally posted by larryw:
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1. What is the appropriate solvent to flush the existing evaporator core and valve to clear out the old R12 oil?

Google up "AC flush" and you will find some products that are purpose built for flushing AC lines. Some you hook up to an airline and blow solvent through the system.

NAPA lists a replacement screen for the expansion valve #207366 but for around $30 you can replace the valve.I have been using a flushing system like the one dave2811 is showing for about 4years now without problems.the instructions state you can use shop air or nitrogen with the flush i use shop air also as a compressor wears it releases small particals that end up in the evaperator. You dont have to use the canster,a good blow gun w/rubber tip will work.pour the flush into the large end of the evaperator [reverse flush] about 10oz at a time,shake it around for 2 to 5 min.then blast it out,catch what comes out so you tell when its clean. The instructions say to let the shop air run for 20 to 30 min,to dry up the flush.I take it into the sun or pull the hood down w/engine running to help out.I installed a/c in 6915 last year you can see photos at the detomaso registry.hardest part was finding stryfoam for the evap box.you cant use spray/expanable foam! also evacuate the system for at least 1 hour and use virgin freon,not from a recycling machine

LarryW, some Pantera-savvy shops remove the screen filter when converting the system to less efficient r-134a freon, in order to increase flow thru the system, and thus increase the coolness a little. Much of the crap that gets caught is from the insides of old rubber lines, disintegating dryer pellets and the inevitable compressor wear. With modern hose & dryer replacements, maybe the screen isn't that important anymore? Anyway, quite a few Panteras are now running screen-less.