Air Conditioning 'low pressure' connection & leak question(s)

trimster · April 3, 2021

Looking at the fittings on my trucks Air Con system, it seems that the low pressure connection is rather inconveniently located above the valve cover on the firewall. Is this correct? The high pressure side is easy to get to, on the line coming out of the radiator, pretty much above the compressor.

Second air con questions... there seems to be a leak in the low pressure side at at tubing connection point behind the engine air filter housing. This is dripping down right onto the hot exhaust manifold. I'm having to imagine that the drip is the oil in the air conditioning system? Are connection points in the air conditioning tubing rebuildable? Pull it apart with the proper tool and add a new o-ring/gasket do-hicky? Is this something most air conditioning service providers can deal with or is it a 'big truck' kinda service provider I have to look for?

Thanks all.

Darryl&Rita · April 3, 2021

A/C repair shop. Backyard mechanic, if you've got a vacuum pump and system gauges.

trimster · April 3, 2021

Got the gauges, not the pump.

I just put in a can and cold air returns. Nice!

Darryl&Rita · April 3, 2021

2 minutes ago, trimster said:

Got the gauges, not the pump.

I just put in a can and cold air returns. Nice!

The new cans of Freon are pretty fancy, gauges and everything. Almost cheating.

NeverEasy · April 5, 2021

I rebuilt my entire AC system a couple of years ago. Had a hard time finding the right seals. Bought a few generic seal kits to get some of them. The one from Volvo had some of the seals but not all. Worst leaks were those you pointed out, on the firewall behind the air filter. The others bad leaks were under the bunk. Easy to get to from the side storage door. A can of freon with leak detector and a black light helped locate the leaks.

To check it before even putting on the vacuum pump, I charged it with nitrogen then used the Whisper leak detector and kids bubble soap to find leaks. Nitrogen is not necessary, you can use shop air since you will have already exposed the system to the environment. It will still need a 24 hour vacuum down before installing new freon. Fortunately, I have a heavy duty vacuum pump and did all the work myself.

rollinbrian · April 5, 2021

5 hours ago, NeverEasy said:

I rebuilt my entire AC system a couple of years ago. Had a hard time finding the right seals. Bought a few generic seal kits to get some of them. The one from Volvo had some of the seals but not all. Worst leaks were those you pointed out, on the firewall behind the air filter. The others bad leaks were under the bunk. Easy to get to from the side storage door. A can of freon with leak detector and a black light helped locate the leaks.

To check it before even putting on the vacuum pump, I charged it with nitrogen then used the Whisper leak detector and kids bubble soap to find leaks. Nitrogen is not necessary, you can use shop air since you will have already exposed the system to the environment. It will still need a 24 hour vacuum down before installing new freon. Fortunately, I have a heavy duty vacuum pump and did all the work myself.

Would live a parts list from that project if it's still handy.

NeverEasy · April 6, 2021

Sorry, no parts list. I started my Gen 1 project by going to Volvo and ordering their Air Conditioner rebuild kit (joke!). That got me about 1/2 the seals. Then I went to NAPA and got as many AC kits as I could. There was one big green o-ring that none of the usual places had. I got it out of a book of seals at Tidewater Fleet Supply. The book said it was for a Mercury Grand Marquee.