[Archived]

Speakiing of gauges for A/C systems, why aren’t they permanently installed? Cost? Room? or would they be potentially a sources of leaks?

[Chuck & Katrina]

With the buying public being so cheap they tend to squeeze a nickel until the bull shits, adding a set of quality gauges is going to be an added cost that will not help a high percentage of owners.

A set of gauges is more than gauges. It is a means of regulating refrigerant flows into the system plus by connecting a set of gauges to a vacuum pump / recovery device it becomes an important tool the technician can move around and be in his line of sight as he works on the system. Often gauges are only one part of the tool kit which can include leak detector, scale and thermometers.

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2000 Featherlite H3-45

2024 Jeep Grand Cherokee

Leesburg, FL

[rafael]

Something is bad in the system if its opening the 450 psi relief valve. Probably multiple things are bad. On a healthy R134a system, I personally have never seen more than 250 psi. The high side safety switch on mine opens the clutch circuit(disengages the clutch) at 320 psi, so it should never dump Freon out the 450 relief valve.
Last summer I had to replace the old drier/filter because it was causing a restriction. Here is a LINK to a thread I did about it.

[DON]

Don have a new dryer on mine but have an extra to put on. Chuck, you crawled under coach with condenser bay door closed and could see floats? Mine is sealed from bottom. Jon, running the same expansion valve from R22 but have the 134 valves to install if needed. Have run R22 expansion valves for 7 years and all was good. Need a tent camper i guess.

[Hisham]

And here is all my HVAC stuff that I’ve accumulated over the yrs. I have R134a for the bus etc, R22 for the CruiseAirs, and even some R410 for my shop mini-split.

[Archived]

Started and ran system for about 15 min. Ball seamed to rise and fall from the top to the middle on the lower sight glass during the 15 min of running. Eng was at idle not high idle.

Glens:

See attached picture looking from the bottom up.

Chuck

[rafael]

Chuck, if as an example the expansion valve wasn’t opening and metering the flow the system high side pressure would go easily up to 450 PSI. It could be one of the situations where it is a little cranky, but not always. This is where the gauges come into play. If you want to do it yourself treat yourself to a cheap set of gauges from Harbor freight, You are not looking for accuracy but are looking for abnormal or intermittent operation.

And yes system temps are important, but they are only a small part of the story, and with the ball in the center of the lower site glass it suggests to me the system charge is close enough to what it should be that your issues are not related to the charge.

Run it at high idle if you can, and if it isn’t working use a brick or cinder block to step up the revs because that will provide the best information.