113 Guests, 0 Users

Author Topic: 78 2.3L Bobcat wagon a/c help  (Read 1864 times)

0 Members and 1 Guest are viewing this topic.

boughtabobcat

  • Guest
78 2.3L Bobcat wagon a/c help
« on: May 25, 2014, 07:01:11 PM »
well, I've been tackling the smaller projects needed o get my wagon running good as a daily driver now that the weather has broken her in Wis., and I'm going to try and get the A/C running before it gets too warm- my car hasn't been upgraded yet and still has the old R12 fittings (I checked against the set of a/c gauges I have for my last car) and I know I'm going to have to buy an retrofit/upgrade kit, but my question is this- I see 3 valve nipples: one on the evaporator casing at the firewall, one on the receiver drier at the radiator and another on what I believe is the high pressure hose going to the compressor. Are there any others to look for? And which fitting should I use to refill the refrigerant? The older a/c system is a bit more confusing to me....

Offline flash041

  • PCCA VIP
  • Pinto Master
  • ***
  • Posts: 883
  • FeedBack: +88/-0
  • Gender: Male

  • Total Badges: 8
    Badges: (View All)
    Tenth year Anniversary Topic Starter Signature Poll Voter Windows User Linux User Mobile User Fifth year Anniversary
Re: 78 2.3L Bobcat wagon a/c help
« Reply #1 on: May 25, 2014, 09:16:27 PM »
I put in an oem a/c unit and retro-fitted it in my 78 with 2.8. Dont worry about the valve on the evaporator by the fire wall. On mine the fitting on the reciever/dryer is the high side. For the fitting I got a kit that included a Tee and a high/low pressure switch. The switch is needed in a conversion since R134a operates at a higher pressure. The low side (fill port) on mine is in the large, suction hose to the left of the radator. The 2.3 may be set up differently.
1978 Pinto Cruising wagon (I am the original owner ! ) Built Aug 15th 1977 in NJ
1993 Mustang LX 2.3 convertible

Offline amc49

  • PCCA VIP
  • Pinto Master
  • ***
  • Posts: 1256
  • FeedBack: +242/-1
  • Another Pinto Driver

  • Total Badges: 4
    Badges: (View All)
    Topic Starter Poll Voter Windows User 1000 Posts
Re: 78 2.3L Bobcat wagon a/c help
« Reply #2 on: May 25, 2014, 11:38:57 PM »
Any line that runs from compressor to the condenser area or receiver at front of car is the highside. The evaporator line out of firewall and straight to either an accumulator or the compressor will be the low side. Line from condenser or receiver to firewall will be highside. The highside and lowside fittings are different sizes and for a reason, trying to charge into the highside can blow up the can of refrigerant and take off fingers or worse. I personally knew someone it happened to. Highside pressure can reach anywhere around 175+ (R12) to over 300 psi (R134A), the cans that refrigerant come in are only maybe 75 psi. You can see how that will be a problem.

You ALWAYS charge on the LOW side for safety reasons.

Usually two fittings only, a low and a high but an old car could easily have extra when someone alters something. The simple one-side-only charging hoses will always be equipped with a low side fitting hose. They do not even provide the ability to read highside at all as that is where the lawsuits will come from when an incompetent person blows up something in his face. Problem is, it is extremely difficult to know how much to charge using lowside only pressure readings. No self respecting A/C man would ever do that.

Not as simple as simply replacing the R12 with R134A, the oil in system is different, the o-ring material is as well. The receiver or accumulator whichever used in the system has a different type of desiccant (the actual drying agent) in it as well.

Offline r4pinto

  • Pinto PooBAH
  • ******
  • Posts: 3779
  • FeedBack: +106/-0
  • Gender: Male
  • All hail Ford Pinto!!!!

  • Total Badges: 9
    Badges: (View All)
    Topic Starter Signature Poll Voter Linux User Mobile User Windows User 1000 Posts Tenth year Anniversary Fifth year Anniversary
Re: 78 2.3L Bobcat wagon a/c help
« Reply #3 on: May 26, 2014, 01:41:54 PM »
Sounds like a lot of hard work, but definitely worth it once it's done! I would LOVE to drive my Pinto when it's warmer out (once it's running that is). Major issue is the lack of a/c. one of these days the car will have it, as any more it's too hot not to. So I guess in the mean time I will keep dreaming & be jealous of those of you able to get the parts to do it, the entire time driving my 08 Grand Prix with nice air but lousy gas mileage.  :(
Matt Manter
1977 Pinto sedan- Named Harold II after the first Pinto(Harold) owned by my mom. R.I.P mom- 1980 parts provider & money machine for anything that won't fit the 80
1980 Pinto Runabout- work in progress

Offline amc49

  • PCCA VIP
  • Pinto Master
  • ***
  • Posts: 1256
  • FeedBack: +242/-1
  • Another Pinto Driver

  • Total Badges: 4
    Badges: (View All)
    Topic Starter Poll Voter Windows User 1000 Posts
Re: 78 2.3L Bobcat wagon a/c help
« Reply #4 on: May 26, 2014, 03:37:50 PM »
I retro'ed my '88 Tempo back around '93 or so and works fine. The higher pressure switch is desirable but not necessary and the orifice close to same size too. The biggest thing is the condenser, which ramps up about double its' fin area when going to R134A, I had a back to back comparison with '88 and '94 Tempos, the two parts were different. You can get around that with an add-on radiator electric fan. The system will not have enough efficiency if you don't address that.

Even so, does not really address the bigger problem to me, or getting a blower motor that makes it all work well. The replacement blowers you get over the counter are absolute crap. I have never found one that will work even as well on high as the factory one did on 2 when working right. Not a problem getting the air ice cold at all, just not enough of it. Somebody bringing out a blower that really moves air could make a million dollars in my view.

Offline amc49

  • PCCA VIP
  • Pinto Master
  • ***
  • Posts: 1256
  • FeedBack: +242/-1
  • Another Pinto Driver

  • Total Badges: 4
    Badges: (View All)
    Topic Starter Poll Voter Windows User 1000 Posts
Re: 78 2.3L Bobcat wagon a/c help
« Reply #5 on: May 26, 2014, 03:57:21 PM »
I got A/C charging hose setups laying around. I ended up using the oldschool high pressure fitting on my Pinto along with a newer R134A lowside fitting to charge with. Reason being the newer highside 134 fitting had a swivel in it to accommodate the oddball dealer add-on A/C on the car. The swivel was garbage and leaked heavily being crap Chinese part. So on that one I had to use a cobbled up split hose type setup.

I added a 10 inch condenser fan as well to help things out. The A/C worked fine and cooled well. I modded the dash to make another outlet in the middle that could be aimed around in 360 degrees.