Putting A/C back together 78 280z

[Usain_Boat]

I'm In the process of back together my A/C system and have a few questions. First off, I have the drier that the flare fittings are right next to each other and not offset like the 33286 drier. Since I have this type, can I just use a direr from a 280zx? And if I do will it have the pressure switch? Second, I believe it will be easier in the long run just to use R134a so what all needs to be done to prep for this? I have no clue what the state of the system from my car was because the PO took it apart... Also I went ahead and picked up another full system off of another Z to replace some of the mangled and seized copper tubes. 

[cgsheen1]

Picture of your receiver/dryer? They sell a cleaning fluid for A/C systems at the auto parts store - read the usage instructions and see if that's something you're interested in doing. I've run 134a in my stock A/C system since I put this car back on the road 9 years ago. To convert, get as much of the mineral oil out of the system as you can. Replace it with ESTER OIL not PAG (unless you can completely remove the mineral oil from the entire system). I use Ester Oil in mine and it works well. If you have a stock blower, replace it with the KIA Sportage blower - search, you'll find a KIA blower upgrade thread.

Many people don't do flare fittings correctly. Make sure that all the mating surfaces are clean. Don't over tighten. Use a little refrigerant oil on the mating surfaces and on the back side of the tube flare (where the nut will cinch up). Snug the fitting - don't over-tighten. (When you over-tighten a copper flare, the heat causes micro-fractures = leak. Better to under-tighten, test joint with soapy solution after you pressurize, tighten more if necessary.)

(last time I replaced my receiver/dryer I could get a stock one. I bought a universal and a ZX - either will work with some manipulation (of the bracket and/or the tubing). The nice thing about copper refrigeration tubing is that it bends (and flares). You can bend the tubing to fit if necessary - you can even make a completely new tube - it's standard 3/8" refrigeration tubing on the liquid (high pressure) side. The receiver/dryer I got has standard ports for the high pressure switch to be screwed in.)

[Usain_Boat]

I have already done the Kia blower swap and I'm ordering a 280z drier but I noticed the screen filter on the high side going into the evaporator is gone. Is there anyway I can replace it? Also, The low-pressure switch seems to be pretty messed up where can I buy a replacement?

[Dave WM]

you can prob find an universal in line filter to replace that with. You may want to make up some new copper lines as well, those look pretty cruddy.

Four Seasons - 34506 - Pancake In-Line Filter w/o Desiccant for Liquid Line

Not sure if that would fit the line you have, but you get the idea.

 

Edited July 2, 2019 by Dave WM

[cgsheen1]

The early Z's did not have a low pressure switch - those didn't come until the ZX. The Pressure Switch on the '74-'78 is for high pressure. You should be able to substitute a generic (universal) High Pressure Switch and the thread on those is pretty standard.  Just a little rewiring of the connection. That's too bad about the little filter - you need the brass part to make the flare work. 

[wal280z]

On 7/2/2019 at 2:33 PM, Usain_Boat said:

While you are at this point, you may want to replace that rubber grommet shown in your picture with something newer.... see this thread > https://www.classiczcars.com/forums/topic/60855-280z-replacement-ac-line-rubber-gasket/

 

[Dave WM]

if it was mine I would just look into new copper and make some new lines. Enemy of AC is any kind of crap in the system. Get some new flares and use that pancake filter.

[Usain_Boat]

What size lines/fittings and where can I get said items to remake the lines?

[Usain_Boat]

So I got a new reciever drier but now my high pressure switch. What am I looking for when replaced it? Can I use a binary switch that fits or does it have to be a high pressure switch?

[Dave WM]

19 minutes ago, Usain_Boat said:

So I got a new reciever drier but now my high pressure switch. What am I looking for when replaced it? Can I use a binary switch that fits or does it have to be a high pressure switch?

binary should switch at both high and low, so it should work fine, extra protection from too low Freon.

[Dave WM]

On ‎7‎/‎3‎/‎2019 at 7:02 PM, Usain_Boat said:

What size lines/fittings and where can I get said items to remake the lines?

going to have to work that out yourself, best bet would be to go to a AC shop and take the old line with you. Its a simple flare fitting, and stanrdard size line.