My AC compressor seems to have sprung a leak on my 2007 3.5SE. What all do I need when replacing it myself?

Not going to be easy on a VQ35, especially without a lift. You'll need new o-rings, a container of PAG oil (Nissan type S or aftermarket PAG 46), a see-through plastic cup, and if it's an aftermarket compressor, a couple of red solder-shrink splice connectors (I'll explain below). If the belt isn't new-ish then you might as well change it while you're in there. I usually loosen the big bolts on the subframe to make enough room to get the compressor out. Take the rear ones loose a few turns and then remove the front ones with a jack underneath to let the whole engine and cradle tilt forward. Nissan recommends draining both the new and old compressors, with the old one drained into a cup. Mark the level with a piece of tape and then add the same amount of PAG to the new unit. For aftermarket compressors the connectors are a complete crapshoot, and if you happen to get a bad one it will make intermittent contact and you'll pull your hair out trying to figure out why the clutch intermittently won't engage. So strip the connector off the OE compressor and solder-shrink it onto the new compressor. Goose the o-rings with a little vaseline when installing the new ones. Please don't f#%k around venting the old system to atmosphere, the greenies may be wrong about some things but they're right about what freon does to the planet. Unless it's already leaked out, let somebody with an A/C machine recover the R134 before repair, and get it evac & recharged properly afterward.

All of the coolant already leaked out but I don’t think it was freon. It was serviced two years ago. Thanks for your explanation. I’ll try to make sure it’s not an after market compressor. Any suggestions where to buy them?

If it isn't freon (R134) then it isn't from the A/C compressor, the A/C system only contains freon, PAG oil, and possibly green UV dye. If it's green liquid and it isn't oily then you're leaking radiator coolant and not refrigerant.

Nissan compressors are very expensive and there's nothing wrong with aftermarket, just don't trust the clutch connector on them. Solder-shrinks are cheap.

In California Freon has been banned for years. An alternative is used. How about UAC? They claim they only make OEM exact fit compressors. What are solder shrinks for?

Yah, UAC is fine. I've installed several for customers and no complaints.

No one uses R12 anymore, but R12 and R134a are both CFC's and both "freon" colloquially, R134 is just less damaging. The new R1234yf actually represents the first real breakthrough ever, breaking down environmentally in days instead of years or decades. It needs special handling due to flammability, but so did the alcohol used in the very first refrigerators. I'm sure the next generation will lick the flammability problem, and very likely be backward-compatible to boot. Technology marches on.


Just a mind-blowing side note, but the reason it marches so quickly is that 90% of the scientists and engineers who ever lived are still alive and working -- and that's been true since the time of Jesus. Ain't compound interest amazing?

carib909 wrote: ↑

Sun Feb 27, 2022 12:09 pm

What are solder shrinks for?

For making sturdy, waterproof butt splices in wires. The OE connector gets cut loose in order to swap it, so you need to rejoin the leads.

Thanks.

You're most welcome, happy motoring!

How'd he do that big hand thing ?.............. I'm just a simple cave man .

lol. I’m not sure why it got so huge. Just emotican on my iphone. Try it.

Gotcha......I'm a Neanderthal , my i-phone does CALLS ONLY (my bad) LOL