adam78280z Posted August 31, 2012 Share Posted August 31, 2012 So has anyone here cleaned out their expansion valve only to end up with a leaking O-ring? I'm a mechanic and work on hydraulics on a daily basis. I must have spent 2hrs trying to re-assemble the valve with a new o-ring with zero success. The fit is tight and there is no taper to allow the o-ring a smooth transition into the housing. I greased, picked, prayed, cried, danced, etc. Does anyone have any information that could aid in getting this assembled without leaking? I have a spare core but it has been sitting for years taped up and defeats the original purpose of taking the valve apart to clean it. Quote Link to comment Share on other sites More sharing options...
bigbore468 Posted August 31, 2012 Share Posted August 31, 2012 So has anyone here cleaned out their expansion valve only to end up with a leaking O-ring? I'm a mechanic and work on hydraulics on a daily basis. I must have spent 2hrs trying to re-assemble the valve with a new o-ring with zero success. The fit is tight and there is no taper to allow the o-ring a smooth transition into the housing. I greased, picked, prayed, cried, danced, etc. Does anyone have any information that could aid in getting this assembled without leaking? I have a spare core but it has been sitting for years taped up and defeats the original purpose of taking the valve apart to clean it. Yeah been down that road before... As you know, you get only ONE CHANCE per new 0-ring when trying to reassemble the expansion valve guts into the housing. That o-ring is an unusual size too. The last one of those can style expansion valves I cleaned out, I machined a small radius on the edge that pinches / cuts the o-ring when you press it back into the housing. I've since found a very close fit standard expansion valve that works well; at least with the stock evaps used in 75 to 76 year 280's. Four Seasons part number 38608. Good luck! Quote Link to comment Share on other sites More sharing options...
adam78280z Posted August 31, 2012 Author Share Posted August 31, 2012 Did you use that standard expansion valve to replace the canister style in my 78 280? I braze a/c lines and such but that looks like a total pain. Quote Link to comment Share on other sites More sharing options...
bigbore468 Posted September 1, 2012 Share Posted September 1, 2012 Did you use that standard expansion valve to replace the canister style in my 78 280? I braze a/c lines and such but that looks like a total pain. Yes, that Four Seasons 38608 expansion valve was used to replace the OE canister EV. Mine is a 76 S30, but I think the boxes are the same from 75-78. The stock lines going in/out of the evap box should be copper so it's easier to bend if you need to. The stock fittings are SAE flare, not AN; but you probably know that already. Hopes this helps you out. Quote Link to comment Share on other sites More sharing options...
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