Brand new A/C from scratch - '88 Mustang

[swampy 6x6]

hi
many custom systems out there in operation
R134a sight glass running full
How u ask because the condenser is either very large or the vehicle / machine uses 2x condenser cores
high pressures common 150--200 psi in 90 --115f ambient weather and high humidity

Compressor oil R12 and R134a for ----- when doing custom work
Ester was fine for R12 which were going to be at next gas recharge fitted with R134a . [ Use the correct quantity of oil ]

[bohica2xo]

Maverick:

Tbird pretty much covered it. If you want a performance assessment, 1500+ rpm, fan on highest speed and door open. Run it for 90 seconds to stabilize and take pressures and vent temp while still above 1500 rpm

High side should be between 2.2 - 2.7 times ambient temperature.

Glad to see it all worked out for you

[Maverick9D@gmail.com]

Given that you are using the precious R12, I would add that a good investment would be an electronic sniffer, and I would sniff the system every once in a while to head bad things off. But that may just be me. I would be lost without my sniffer

I actually did buy a sniffer along the way. My investment in A/C tools for this project is probably more than what the average person would do for just a single car, but in the process i've gained a lot of know-how.


Next drive or so, i'll need to hook up the manifold gauges and get some pressure readings. Problem is when i take the car for a spin, i'm usually tight on time and squeezing it in between kids activities, so we will see when I can actually do this.

One question, when hooking manifold gauges up to a system, i would imagine there is some refrigerant loss into the lines. How much refrigerant loss does this add up to?

[bohica2xo]

The answer is "some".

You can minimize the loss by disconnecting your high side coupler at idle.

Then make sure the yellow charging line is blocked off. Should be a dummy fitting on your manifold set to screw the hose on to. Or use a hose with a check valve. Or screw it on a can tap. Just make sure your charge / vac hose does not vent to atmosphere.

With the system running, elevate the rpm if needed to find the lowest pressure on the low side.

Open the high side valve and the low side valve to allow any liquid refrigerant collected in the high side line to return to the low side through the manifold set.

Once all of the lines are at the lowest pressure available, close both hand wheels, and disconnect the low side coupler.

[tbirdtbird]

You are bleeding the liquid in the red hose back into the system via the blue hose which has vapor only. Be sure to disconnect the high side coupler from the car as mentioned. Be mindful, as Brad said, of not getting air in the system from the yellow hose....think carefully about what you are doing.
Or just shut the car off and let the system cool down for a few hours and the pressures equalize to ambient, which will be about 70 psi, then disconnect, you will just get a slight pffft of loss which is minimal

[Maverick9D@gmail.com]

Makes sense. Thanks for the help everyone.

[tbirdtbird]

And be sure to keep the plastic caps on the ports....the schraders like to ooze. The plastic cap is the final seal (believe it or not)

[fastsvo]

EDIT: Update. System is complete. See post #19 for follow-up question
Hi All,

I recently spent a couple years rebuilding my 1988 Mustang 5.0L and part of that rebuild consisted on reinstalling the AC which i had removed many years ago.

The entire system is brand spanking new. I was able to source many NOS Ford/Motorcraft parts. All the lines are NOS, the EVAP is NOS and i rebuilt the Nippon-Denso 6P148A compressor (which was in excellent condition prior) using a new seal kit. I replaced the internal seals and shaft seal. Everything is clean, fresh, and ready to go. All the older NOS lines had their O-rings replaced with fresh new O-rings compatible with R12 or R134a

I am about to embark on a similar voyage with my 1991 GT using R12. Could I ask where you were able to find those NOS parts? Any links available?

Thanks!

[Maverick9D@gmail.com]

I am about to embark on a similar voyage with my 1991 GT using R12. Could I ask where you were able to find those NOS parts? Any links available?

Thanks!

Search item # 182561762901

I am running an aftermarket condensor however. That's the only non-Ford part.

----


Oh and as a update to the thread. Wrapped up the season using the A/C every time i drove the car. It worked flawlessly. I never hooked up manifold gauges to it again to check performance as it just worked so well. I saw vent temps in the 35-38 degree range, at idle, on a hot/humid day with the doors open. I figure that was good enough.

Cruising to a car show on a 90 degree day in a black/black car never felt so comfortable.

[tbirdtbird]

Good job, thanks for getting back to us!