Give insight to my gauges...

[carboncow]

Been a few years since I did an DIY on auto AC but have installed some mini splits over the years!

2012 Honda Ridgeline (220K miles) and it gets cool enough when working as inferred gun says 42-44F at the back of the air inlet. Noted now that we are had a 80F day and had to road trip the kid to camp...AC went dead started to suspect a bad compressor not doing well at RPM but got back to the lake house. Noted clutch is engaging and turning fine and the AC started working again around town. Noted air filter was in terrible shape so a new cabin filter improved air flow (and cooling a lot).

then drove home from the lake at 60mph for 2 hours but when we got to 70mph the ac went out again. Now home and it will not work at all and clutch is still engaging. Now I've got the gauges on it.

Resting (no clutch) at 78F with humidity is 65%
Low Side: 15psi
Hi Side: 210psi

Clutch engaged
Low Side: 0psi
Hi Side: 230psi

After 30 minutes the low side is still 15psi and the high side is still 200psi. Shouldn't this equalize through the expansion valve or filter/dryer side of things or does the compressor and valve hold the pressures on each side?

So I'm holding pressure, seem to have freon in there and hit it with my extra can from the auto zone and the dumb gauge on it had it in the green. Doubt I can trust this but at only 15psi resting...maybe that is terribly low? I mean clutch is engaging wouldn't modern car have the clutch not engage if the low side was too low to keep from damaging compressor?

Does this sound like a leak as my one cheat sheet says or are we thinking a stuck expansion valve maybe?

Cannot attach file so screencast here: https://www.dropbox.com/s/h28tdg25hjcwf ... 6.jpg?dl=0

[tony1963]

I'm going with a stuck expansion valve.

[bohica2xo]

How much history do you have on the vehicle? 220k miles is way past the average lifetime of a scroll compresor...

[tony1963]

To answer another of your questions, yes, systems do have a low pressure cutout switch. The idea is that with low refrigerant pressure, there is not enough refrigerant in the system to carry around the oil and thus, it will destroy the compressor due to lack of lubrication.

Think of this as a low oil pressure cutout.

[Tim]

How much history do you have on the vehicle? 220k miles is way past the average lifetime of a scroll compresor...

Doing some research, I was wrong when asked today if it were a scroll. My question would be, do we know if this system has the proper refrigerant level? Not by pressure or adding a little more mentality. Factory spec amount after the system has been evacuated?

[bohica2xo]

Tim I was interested in the static pressure @ 78f being 210 psi...

[Tim]

Tim I was interested in the static pressure @ 78f being 210 psi...

Possible restriction. I would do more research before tossing parts at it.

[tbirdtbird]

I would have reclaimed and recharged to factory spec. And used a proper manifold gauge set. Those little low side gauges are piss poor. And then we have this to contend with:
" hit it with my extra can from the auto zone and the dumb gauge on it had it in the green"
so undoubtedly there is sealer in there now

Those quickie kits are to be avoided at ALL costs. Nothing ever into an AC system but pure R134

And pressure hi and low need to reported with RPM at 1500, max fan max cool recirc doors open along with ambient