All new A/C system--> big problems. Help??

[Dropped88]

@Dropped88 you nailed it!! That was the problem!! Thank you so much for your post and help!

While I did check the new orifice tube while putting this all together, later when I was fighting hooking up the lines I didn't think about it because I'm kind of used to the O-tube being back near the firewall. The new lines were not fitting up well at all, and in trying to get them properly bent and aligned and hooked up, YEP, I got them backwards and consequently the O-tube not at the right point in the system.

GOOD CATCH Dropped88!! Thanks again. You know, I researched the problem for hours, and posted in no less than five forums. You were the only one to nail it. I'm embarrassed here, but way happy to find the problem. (Note that some said "check the plumbing" which was also correct, but he nailed it dead on.)

I was tearing my hair out, so I can't thank you enough! (Hey, been doing this mechanic stuff for 55 years, so I don't have much hair left to pull out!)

God, now I've got to dig into malfunctioning HVAC doors. Probably all three actuators. I really, really hate interior and dash work...

THANKS!!
Vettepilot

Your welcome thats what this place is all about is helping each other. And i don't have as much experience but the 13 yrs doing it professionally. I've seen some crazy stuff.

 

[Vettepilot]

Oh yeah! The stories I could tell...

Thanks again. Got the lines switched and system vacuumed down. Will add freon this evening.

Vettepilot

 

[Vettepilot]

Well guys, are ya still here?? This saga ain't over...

So finally this evening I got my gauge set fixed. It is old and tired and I had to repair it. I vacuumed down the system for 1 hour plus like I usually do,, and all good. Shut down the vacuum, and the system held for 30 minutes - no leaks.

Feeling pretty good at this point...

Then I started charging the system, or trying to... With freon hooked up, when I opened the low side valve a little, the low side gauge went from vacuum to about 60 psi or so. High side was just over 125 psi. But that was it. Period. It never drew in the freon. I fought with it for about 30 minutes, then quit as I was worried about damaging the new compressor due to lack of flow. The low side connection felt cool, (not cold) to the touch, and the high side quite hot. Unlike normal, I had to jump the low pressure switch to get the compressor to kick in. Usually, the vacuum draws in enough freon that the compressor kicks in and I don't have to jump the low pressure switch, but not this time.

What do you guys think?? My only guess is that 450 psi of reverse pressure from when I had the lines reversed seriously damaged the orifice tube and now it doesn't want to flow.

Why is it that hundreds and hundreds of my various customer jobs go just fine, but when working on my own stuff, things go to crap!!??

I'm so bummed right now. I've had two serious back surgeries and I'm now due for a third, so I'm trying to get all this done while enduring intense pain.

Ideas guys??

Thanks,
Vettepilot. :~(

 

[GoToGuy]

Did you use a new orifice tube? " Low side pegged..." , What exactly did you see?
Test low pressure switch, may be damaged from overpressure. Or just replace it, service manual reads can be replaced without draining system. Schrader valve under switch. It's not the vacuum suction, that's minor, it's the can pressure raising the system pressure closing the low pressure shutoff switch.

 

[Vettepilot]

Well, actually that low pressure switch is the least of my worries. As you say, that's easily changed if need be. But I've got to get the system flowing.

Normally when I service most systems, I have the system under a vacuum, and when I open the low side valve a bit, the freon starts quickly flowing in. So quickly that I modulate the low side valve to keep it flowing at a reasonable rate. Generally then, sometime during the time the second can is going in, the compressor kicks on, and I finish charging as normal.

With this one, when I cracked the low side valve, I got the expected low side gauge response, and the high side came up just over 100. But it stopped there, and no more freon flowed. As I said, I fooled with it trying various things for about 20 minutes or so, then shut it down. The freon just would not flow after that (seeming) initial flow. The can stayed full feeling and warm.

The entire system is new, including the orifice tube. I had accidentally hooked the condensor lines up backwards and the pressure went nuts. The compressor hit 450+ psi multiple times with the safety switch kicking in and shutting it off, (cycling) due to those reversed lines. I found the problem and put the linee on correctly, but did not change the orifice tube.

So the orifice tube was subjected multiple times to very high pressure in the reverse direction. Do you think this could be my problem now?

Thanks!
Vettepilot

 

[Supertex]

I had something similar when I charged mine recently. Just posted about my fiasco, actually. But when charging, it just wouldn't take freon at first. I kept shutting the low-side gauge, and then cracking it open again, and the gauge would jump a little each time, but diminishing returns came into play. We eventually shut the truck off for a few mins, closed the valve, waited 3-5 mins, fired it back up, and when I cracked the low side valve this time, it flooded the sight glass and emptied the can and didn't see another issue. I wondered if there was some sort of trash inside the freon can that was getting against the puncture point.

 

[GoToGuy]

Old style puncture cans or new epa self sealing valve cans. You have use the correct can valve.

 

[Jeepwalker]

Piece of crud in the orifice? Do a google or youtube Q&A on common AC problems, or just type the problem into google as you described it.

Note, if you hook up a can of 134 to your system and place it in a pan of hot water, the refrigerant will leap right into your system!

 

[Vettepilot]

It's the self sealing can and the can tap I've used for years.

I'm guessing the orifice tube got damaged and needs replaced. It sucked in freon and made pressure with the condensor lines reversed. LOT'S of pressure.

Vettepilot

 

[Vettepilot]

Ok guys. After the hose switch-up on my truck, I decided my gauge hoses were too old to use anymore, so I switched them out for a backup set I had. Turns out, the blue hose on that set had a blockage. The sealing washer was covering the outlet holes.

All fixed now, and A/C blows 37 degrees!!

THANK YOU TO ALL THAT ANSWERED!
Vettepilot