dixie wrecked

iTrader: (6)

Converted my bird to r134..much better than the windows down ha.
Flushed my evaporator multiple times, new drier, high side line flushed really well, condenser flushed really well, low side same..ford blue orifice tube, new low pressure switch (not that the electrics actually work haha) and new Murray compressor.
Should mention I only have "on or off" (12v dipswitch going to ac clutch) as well.
​​​​​System was vacuumed and charged properly.

​​​Was running alright for a few days, but today it decided to leak at the back of the compressor in a $40 cloud of r134. Seems to be a common issue, since our factory style hoses are level, as the new style r4 compressors are not. They come with a pack of crappy feeling o-rings that seem to seal, but eventually blow.

Anyone have a solution? Hoses from another vehicle that will work?
This car is a mad Max special, so couldn't care less where the parts are from as long as it works haha.

daferris

iTrader: (8)

My hoses (4 seasons if I recall right) came with 2 o-rings both were alum washer style with the o-ring molded to the ID of the washer 1 was maybe 1/16 thick but the other was about 1/8" thick...

dixie wrecked

iTrader: (6)

The Murray one I got had those as well, and is what I used. Held fine a few days, of course until today when it's actually hot out.

daferris

iTrader: (8)

I've never tried this but would doubleing them up work??? Other thing is because it works for a couple of days was the system overcharged? The high ambient temperatures would make the pressure on the high side higher

dixie wrecked

iTrader: (6)

I'm no expert, but definitely don't think doubling orings is ever a good idea.

I don't think so. Manifold gauges were showing 35lb low side, 250lb high side @ 86deg

Drew

iTrader: (58)

Are you sure it was the hoses leaking and not the pressure relief valve on the back of the compressor? Been there-done that with a 134a converted thirdgen.

dixie wrecked

iTrader: (6)

Im not sure actually, didn't know they had a pressure relief valve.
Was sitting in traffic and saw a cloud of freon, enough to choke my carb and kill the engine.
Shut the compressor off and looked after stopping, saw my valve cover/header wrap was pretty wet.


I flipped the compressor on not long ago for ***** and giggles, it was still blowing cold, so maybe that was it? It was pretty toasty out today.

dixie wrecked

iTrader: (6)

Tried again today, since it's a little cooler. At a stoplight and kicked the compressor on, blew cold for a minute and then dumped another cloud of freon, sounds like I have a leak, or over pressurized? I don't have any high or low pressure safeties, only the expansion valve + a 12v toggle on the compressor. Will have to put my gauges on later and see what's up.

Edit: I kicked it back on on the way back from lunch, less stop and go traffic, it worked fine. Only difference is I had one of my fans going, plus wasn't idling very long. Wasn't as cold since it puked out a bit of freon..sounds like its over pressurizing, but why? Perhaps diff orifice tube is needed?

dixie wrecked

iTrader: (6)

It was indeed the pressure relief valve!
I put gauges back in and re filled it up, 35 low side, 250 high on a 90deg day idling at 400 rpm.
It blows cool. Not cold, but definitely cooler than ambient temperature and warmer than before.
if the relief valve opened, would it have sucked a bunch of air in? If I open the nozzle on low side, only warm air comes out.
High side, it'll spurt hot air and liquid 134.
Do I need to now evac and charge my system again?

Drew

iTrader: (58)

I'd be more concerned that after the relief valve opens, it may never hold to the proper relief point again. I doubt it'd let air in, it should theoretically have closed as soon as the escaping high pressure dropped low enough for the valve to close again. In my case I swapped the valve with one from another compressor in the junk barrel. Of course I was starting from an R134a conversion, and I went to a different refrigerant, so I basically started from scratch.

I've never had much luck with 134a in a thirdgen. Just never seems to get cold, makes compressors noisy, causes the belt tensioner to jerk when cycling, etc. That said, I'm not sure that manually controlling the clutch isn't contributing to your problems. The OE system has a few different switches that allow the compressor to cycle on and off as needed to not create an overpressure issue.

dixie wrecked

iTrader: (6)

It seems to have closed, and staying closed now, so I reckon that's good? Wasn't sure if it should be 100% liquid freon in the lines or not though.

Yeah, I don't expect it to be COLD like r12, or like 134 in newer cars, just something to stay cool in the summer. R12 is just too expensive for me to be playing with.
It was fairly cool before the valve made a $20 cloud of freon, less so now. I've noticed it's definitely noisy as you said, but hard to hear over dumped headers hah.
Sadly I don't have a choice on wiring. Bought this thing from a high school kid who "converted it" to carb via just cutting any harness that touched the engine, so the only HVAC wiring I have is for the blower motor only. I don't cycle it though, just leave it on. I forgot r134 and r12 aren't a 1:1 fill ratio, plus forgot to flip an aux fan on on a hot day, so that's likely why it over pressured. I've since wired the compressor to one of my aux fans, that way they both kick on at the same time, haven't had the issue since.

Running on full, the low side/drier feels cool to the touch, but not cold. High side is hot.

I've looked into other refrigerants as well, besides r12 and 134, just not sure what works well.

NINÅ