Extremely high low, zero high pressure

Friendly format provided to inquire about automotive a/c systems.
Archived Forum

Moderators: bohica2xo, Tim, JohnHere

Post Reply
Jpittman
Posts: 5
Read the full article
Joined: Tue Jun 13, 2017 5:16 pm

Extremely high low, zero high pressure

Post by Jpittman »

I recently converted my 90 Miata from R12 to R134-a. I've replaced all o-rings, the expansion valve and compressor shaft seal. After vacuuming I went to charge the system and got some strange results. I accidentally forgot to engage the AC from the dash so I added all 12oz without the compressor running and ended up with pressure on both sides at about 105psi (pretty hot day). I engaged the AC and the high immediately went to 0psi and the low to 130psi. What gives? No, I DO NOT have the gauges on backwards, I promise. Does this mean my compressor is shot? I also suspect my expansion valve may be trash, I bought it from autozone and when I received it you could tell it had been used, someone had put teflon on the fittings, installed it then removed it.
Jpittman
Posts: 5
Joined: Tue Jun 13, 2017 5:16 pm

Re: Extremely high low, zero high pressure

Post by Jpittman »

Oh also, compressor does not cycle, it runs constant.
Dougflas
Posts: 379
Joined: Mon Apr 18, 2016 6:10 pm

Re: Extremely high low, zero high pressure

Post by Dougflas »

handwheels on gauges closed?
Jpittman
Posts: 5
Joined: Tue Jun 13, 2017 5:16 pm

Re: Extremely high low, zero high pressure

Post by Jpittman »

Yes, closed.
User avatar
Tim
Site Admin
Posts: 1104
Joined: Tue Apr 12, 2016 2:19 pm
Location: Scottsdale, Arizona
Contact:

Re: Extremely high low, zero high pressure

Post by Tim »

Low side restriction.
------------------------------
Please support ACKITS.com for your Auto A/C Parts and Tool needs.

Help Support the Forum
Jpittman
Posts: 5
Joined: Tue Jun 13, 2017 5:16 pm

Re: Extremely high low, zero high pressure

Post by Jpittman »

Tim wrote:Low side restriction.
Please explain
User avatar
bohica2xo
Preferred Member
Posts: 1170
Joined: Wed May 11, 2016 4:12 pm
Location: Las Vegas, NV

Re: Extremely high low, zero high pressure

Post by bohica2xo »

So you bought a TXV from twilight zone, found TEFLON TAPE on it - and installed it anyway?

Yeah, that TXV is probably more like a plug than a valve.

How did you flush the system? What type of oil did you refill it with? Was the dryer replaced?
Jpittman
Posts: 5
Joined: Tue Jun 13, 2017 5:16 pm

Re: Extremely high low, zero high pressure

Post by Jpittman »

Yea I know, I shouldn't have installed it.
I used ester w/ dye and no I didn't replace the dryer. I know most people say it's necessary but I've seen many conversions where the dryer wasn't replaced and worked fine.
Post Reply