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rgnprof's avatar
rgnprof
Explorer
Jun 14, 2016

1993 Ford E350 Vacuum and A/C question

Haven't been on here much lately - too many other things going on...but, we took the RV out last week for the first time in a year and had a great, rather uneventful trip - except for no cabin A/C. Not a huge deal, but I'm in the midst of fixing it right now. The system was EMPTY - so I tried to draw a vacuum, just to see what I had. I really think the problem had to do with the schrader valves, but I'm not sure. I pressurized the system with compressed air (yes, I know nitrogen is better and I know about the moisture issue - I used a filter and I knew I was changing out the drier - at least - when I was done anyway. Didn't find any huge leaks after spraying around and the vacuum got down to 29" or so and when turned off, held steady for more than 10 minutes.

Pulled the orifice tube today and it was covered in really fine, almost dust like metallic particles (they were attracted to a magnet)- pretty clogged up. I'm assuming my FX15 compressor has died - I have a new one (FX10) coming tomorrow, as well as a new condenser. My question is should I replace the evaporator as well? And how concerned should I be about the hoses? I see no signs of oil/leaks and I am having an impossible time finding any replacements for this van chassis...the line from the compressor to the condenser has a muffler installed in it and I've read that you can't really flush those. But, if I get the hose out to where I can turn it upside down, do you think I can run some flush through it? I am planning on flushing the evap and all the hoses - installing new compressor, condenser, drier and orifice tube and going back with R12.

One other question - in taking the drier off the passenger wall, I had to remove the vacuum reservoir. I noticed that nothing was hooked up to it - no hoses running to or fro..? Been like this since I've had the coach (6 years) - should I be concerned about this?

Any other advice/ideas?

Thanks,
Ryan
Class C
  • rgnprof's avatar
    rgnprof
    Explorer
    Jun 17, 2016
    One more question - installing parts today and I'm having trouble matching up the drier connection to the evaporator tube (they're both mostly hard tubes). My question is how much can I bend the evaporator tube to make it fit the drier tube? It's a Four Seasons Evap and it is heavily soldered at the point where the tube connects to the evap core...
  • rgnprof's avatar
    rgnprof
    Explorer
    Jun 17, 2016
    Positive the system originally had mineral oil and I am sure the amount was 7 ozs...I may buy new oil - just to be sure.

    Several problems with running the house A/C, not the least of which is my wife, who rides in the back while we're traveling gets a lot colder a lot easier than I do! We have done that on occasion, but typically find that even on hot days, a functioning dash A/C is enough to keep the front half of our 29 footer cool.

    Also, what color orifice tube should I use? I called the dealer and they said it originally came with an orange one (.057"), but can't find it locally - only made by Motorcraft (I guess the dealer may have one). It had a red one in it (.062") and I can find it anywhere...

    Ryan
  • j-d's avatar
    j-d
    Explorer II
    Jun 17, 2016
    Yes, got the text and glad you got the evap out easily. It looked a lot like the GM vehicles of the '60s - '70s where you could just split a housing and lift it out. Problem with some of those was having to remove the hood hinge, which left a very heavy hood to support while the work was being done.

    Anyhow, we sealed ORings with refrigerant oil for years before Nylog. Nylog is a great product, highly recommended.

    I haven't been in an OIL discussion for years, but my recall is even mineral oil will absorb moisture, over time, in storage, opened or unopened. Products like PAG are far worse about that.

    What I'm trying to say about oil for your project is two fold:

    1. Be sure it's the correct oil type. In this case you want to use Mineral. OK, just be sure that's what the new one came with (which I doubt, in the age of R134A).

    2. That it's the correct quantity. I had a new compressor came with way excess oil. Probably enough for two systems. That's why I think you need to empty the new compressor and fill it to the specified amount. If you want to divide total oil charge up among components, OK. Just be sure the total is right.

    You can roll the compressor over by hand with the clutch face to help work oil out. Some recommend, roll it by hand once assembled, evacuated and charged, before you start the engine.
  • TyroneandGladys's avatar
    TyroneandGladys
    Explorer
    Jun 17, 2016
    We do not run the dash air. We run the roof air and use a fan to circulate the air in the cab. With the front air dam reducing the heat from the dog house we are very comfortable and take a heat load off of the engine.
  • rgnprof's avatar
    rgnprof
    Explorer
    Jun 17, 2016
    I am replacing everything - had the hoses pressure checked today and had one repaired - even though it wasn't leaking. Pulling the evaporator was easy...so I'm going to start putting it all back together tomorrow. Will go back with R12 - any suggestions on sealing o-rings? I've read a lot about Nylog, but the shop that fixed my hose just said to use mineral oil. System takes 7oz oil - I'll probably add about 4ozs to the compressor, 1 1/2 oz to the evaporator and 1 1/2 oz to one of the hoses...I am using mineral oil. I've had some from Napa for several years - opened, but been capped. I guess it's alright???

    Did you get my text back to you?

    ryan
  • j-d's avatar
    j-d
    Explorer II
    Jun 15, 2016
    Be sure you use the appropriate OIL, and also that the Amount is correct. You may have to drain, measure and refill.
  • j-d's avatar
    j-d
    Explorer II
    Jun 14, 2016
    If you have enough R12 to get through the foreseeable future, then sure. Otherwise, now is the time.

    Call acsource and ask for Warren, tell him pesky jd sent you. I think he's a motorcraft dealer. Call early in the day, say 0700. Your E350 cutaway shouldn't be different than other E150-350 for years of production. I don't understand the problem. You may also be able to go to a shop that fabricates hoses. Many NAPA stores, a franchise called Masthead, I'm sure others. If you have that done, make sure they "clock" the ends so they install without twist on them. In other words, if Fitting B faces same as Fitting A, then the replacement should be fabbed with that same facing.

    If you decide to replace the evaporator, you will no doubt end up with better air flow. The old will be matted with debris from air intake. I like to think there's access to change it underhood, but I can't verify it right now. We're taking ours on a trip and I can look at it while we're there. Or, I might be able to get you a clip from professional documentation.
  • rgnprof's avatar
    rgnprof
    Explorer
    Jun 14, 2016
    Hi j-d,

    Great to hear from you! Hope you are well...

    I checked out the link and no hoses...I think the only way to get them is through the dealer - and they are quite expensive. I think I'm going to try and flush them out and see what happens.

    How hard is it to replace the evaporator? Doesn't 'look' too bad - everything seems accessible from under the hood. Parts are cheap, as mentioned in that article - I will spend around $300 to replace everything (compressor, condenser, drier, evaporator, orifice tube), and I'm planning on going back with R12.

    I've already removed the compressor, drier and condenser...pretty easy from here to flush out the hoses.

    Not going to worry about the vacuum issue - haven't noticed any vacuum related problems since I've owned the coach.

    Ryan
  • j-d's avatar
    j-d
    Explorer II
    Jun 14, 2016
    RV.net's having issues. Had to post the above by logging into Woodalls.
  • j-d's avatar
    j-d
    Explorer II
    Jun 14, 2016
    Well, Ryan, it's a Black Death case. The company linked in the article might be able to help with parts like hoses.

    I think you'll read that Evaporators don't flush well. Like radiators and heater cores, they're parallel flow. Condensers USED to be a path run by one piece of tubing, and could be flushed. In parallel, the flush agent will take the path of least resistance (tubes that are NOT clogged) bypass clogged ones. And, you can't blow the flush agent out. It'll lay in the end tanks.

    Oh, the "muffler" in an auto A/C line is simply a chamber, no guts inside, so yes, you could flush it.

    If you install an FS-10 or whatever Ford calls it now, a late model parallel flow condenser, new receiver/drier and new hose set, correct oil, and R134A refrigerant, you can get good A/C back.

    If the vacuum reservoir isn't connected, it must have leaked and somebody bypassed it. If air blows out of the dashboard vents and continues to do so on hill climbing or acceleration, whoever bypassed it used a check valve and added another reservoir. If it blows out the Defrost vents, either all the time or on climb/acceleration, then it needs vacuum through a check valve and hose/reservoir that doesn't leak.

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