AC Schrader Valve Shouldn't Be Leaking

[Fleetw00d]

Son and daughter #4 left Pensacola Thursday about noon in the wagon; traffic and other issues put them in southern KY about 1:00 AM Friday when they call and say "I smell rubber burning". He couldn't see anything obviously wrong, but didn't want to take chances so they went to a hotel. I left Friday morning about 6:30, picked up a tow dolly in Elizabethtown, KY, then went down to Munfordville where they stayed.

Earlier in the evening, the AC hadn't been working and they were having trouble keeping the windows clear. At a gas stop I have him put some R134 in to see if the system would start working - it did.

So when I got there, I couldn't see anything amiss other than the AC pressure switch was wet and AC wasn't working again (still some pressure in the system). I suspect the refrigerant was leaking from the switch and getting on the engine creating the burning smell. The car made it home from there without further problem. Ordered a Honda switch from vintage parts (and pulled one from a yard in Louisville).

Finally looked at it in the light today. Cleaned the area around the switch and the high pressure port. Removed the high pressure cap; it hissed a little as I did so and continued to bubble some (not spray) from the valve.

It looks like there is a seal on the underside of the cap, but this valve isn't supposed to leak even so, correct?

[Raf99]

Son and daughter #4 left Pensacola Thursday about noon in the wagon; traffic and other issues put them in southern KY about 1:00 AM Friday when they call and say "I smell rubber burning". He couldn't see anything obviously wrong, but didn't want to take chances so they went to a hotel. I left Friday morning about 6:30, picked up a tow dolly in Elizabethtown, KY, then went down to Munfordville where they stayed.

Earlier in the evening, the AC hadn't been working and they were having trouble keeping the windows clear. At a gas stop I have him put some R134 in to see if the system would start working - it did.

So when I got there, I couldn't see anything amiss other than the AC pressure switch was wet and AC wasn't working again (still some pressure in the system). I suspect the refrigerant was leaking from the switch and getting on the engine creating the burning smell. The car made it home from there without further problem. Ordered a Honda switch from vintage parts (and pulled one from a yard in Louisville).

Finally looked at it in the light today. Cleaned the area around the switch and the high pressure port. Removed the high pressure cap; it hissed a little as I did so and continued to bubble some (not spray) from the valve.

It looks like there is a seal on the underside of the cap, but this valve isn't supposed to leak even so, correct?

Correct. I've had them leak before. New grommet/cap fixed the issue.

[cp[mike]]

It looks like there is a seal on the underside of the cap, but this valve isn't supposed to leak even so, correct?

Pretty sure that seal is to keep dirt and water out, not to keep pressure in. If the system is already leaked out again, I'd suggest taking the opportunity to replace the R12->R134a adapter that is probably installed on the bleeder. This would be an easy way to replace the entire valve and stem in one shot.

[Fleetw00d]

I was able to tighten the valve some with a narrow bladed screwdriver to the point that it appears to have stopped leaking. While then trying to recharge the system some (it hadn't completely bled out), jumped the connector to get the system to run. I was probing the contacts on the switch and refrigerant starting leaking where the pin came out of the switch. I'll be environmentally responsible tomorrow and find a shop to evacuate it before changing the switch.

[illinois_erik]

you can replace them the little seal on the valve cores do go bad, get you a valve core tool and a new schrader valve core and you should be good, besides the switch =] reminds me of the oil pressure switch when it goes bad and pukes oil.

[Fleetw00d]

Found a place that opened at 7 this morning that would evacuate the system, let me change the switch, then recharge. They wanted to charge 1.3 hours (at about $90/hr) just to change the switch, but they couldn't get one from their normal parts supplier so all I paid for was the evacuate and recharge. 14 minutes from hood up to hood down to change the switch.

[F22Chris]

Those valves had an o-ring suitable for r-12 back when, so if the valves/o-rings weren’t changed for the r-134 ones during the conversion, they would have disintegrated over time.

They leak slowly over time regardless. The black caps I think are there to keep contaminates out so you’re good if you don’t crank them down super hard.

Those switches leak JUST like the oil switch.. super annoying.

[hiptech]

Just out of curiosity did you add dye to the system to help determine potential future leaks?

[Fleetw00d]

I didn't charge the system, so I don't know if they included dye (forgot to ask them that). When I was messing with it, what little came out appeared to have a yellow dye in it.

When it rains, it pours. AC in the Pilot wasn't working yesterday. Traced it to the compressor clutch relay. Got lucky, $7 fix.