Building an A/C system from near scratch

[shumpertdavid]

The only thing I can fill are r-12 systems, we don't have enough demand to buy 20-30 lb drums and use our recovery machine so we just buy a few cans a year. I'll usually sit the can on the motor or where it will pickup engine or radiator heat some to help raise the pressure in it and get the most charge from it. You'll always loose a little with a can fill because at some point the can pressure and the low side pressure will equalize and you'll stop transfer.

[KBScobravert]

Damn low pressure switch that I bought new did not come with an o-ring. Result, leaked and now need to recharge. Of course thd switch is burried in the fender.

[dville_gt]

That sucks. Could be worse. I built my entire system, got over to Buick355's house everything set up, then realized I had no low side port on the system...DOH!

[dville_gt]

(oh, and big lots usually has r134a for $8 a lb)

[shumpertdavid]

Damn low pressure switch that I bought new did not come with an o-ring. Result, leaked and now need to recharge. Of course thd switch is burried in the fender.

pressure switch only goes on hand tight to snug, most of the time I use the o-ring that is on the accumulator when it comes new as the ones with the pressure switch tend to be a little small.

[KBScobravert]

The crappy thing is I was 10 minutes away from jumping in the car to drive to work today. Now I have to get home tonight at 11:30, jack that corner of the car up, pull the tire, pull the inner fender well liner (which is a bitch by the way since I have so much shit going in there) and hope I can get that switch off.

Tomorrow morning is the cruise north to Stillwater for the power tour.

[shumpertdavid]

I wish you the best of luck and a happy trip sir.

[KBScobravert]

I wish you the best of luck and a happy trip sir.

Chas_SVO picked up a switch and dropped it off at the house for me. I think once the fenderwell liner is out, I can slide and twist the accumulator around to let me pop it off then install the new one.

Then I get to charge the system, again. lol

It is going to be an early morning and a long day to get to Stillwater in decent time.

[KBScobravert]

Car up, wheel off, inner fender out, accumulator loose from mount , switch off then reverse = 25 minutes.

Is the low pressure cycling switch still on the accumulator, generally it will cycle the compressor off @ 25 psi. If it doesn't cycle off and on the system will freeze up. I would guess based on the pressures that you are still down some on refrigerant, I'd expect 250-275 with the heat right now and mid 30's to low 40 on the low side. Again, that's where the temperature differential at the evap inlet and outlet would help.

I could only get it to 38-40 an 225-230 compressor on and roughly 80* in the garage and coolant temps at 185*

Temps at the vent on Max AC high fan was 61*.

Using the infrared gun my evaporated lines at the firewall were 102* & 110*

The can couldn't pressure past the system in the end. I think a fresh can would have my pressured closer to what you said.

No sounds of a leak but only a test drive tomorrow will tell.

[shumpertdavid]

with the cooler ambient air the pressures will be lower, i'd give it a run where you are at with the readings. The ir temp guns are useless for testing the line temps. case it point, you can feel the evap lines and know that they are not 100 + degrees as your temp gun is saying. That's why I said you must use a surface temperature probe. It's specifically designed to read the temperature of what it is being touched to without pulling higher or lower temps from the surrounding atmosphere.

[KBScobravert]

I think I am gonna need a bigger fan.

Coolant temps couldn't sustaine the A/C unless we were at speed (50+).

[Baron Von Crowder]

Y'all at qtp?

[davinci]

Quick question guys. I'm in process of building Ac from scratch using my ls1 fbody compressor , universal parallel flow condenser, universal drier with 10mm port for the gm high side switch..and the adapter that goes on back of block. I will be ordering all my barrier hose mocking it up and taking it somewhere here in dfw to get crimp. MY only question is what do I do about orifface tube?? Do I just buy one and slide it into the line at appropriate spot??.

What hydraulic place do you recommend in dfw to crimp my lines. This is all going in my 240 by way I don't have a stang. although my next project will be fox coupe.