AC troubleshooting

[mechanixhorseman]

Hey guys,

Having some issues that hopefully won't stump the more AC savvy. Essentially, my AC clutch does not engage. After reading some other threads and websites I learned that this may happen when there is a pressure loss in the system. I went and bought the cheapo HF AC manifold gauge. There was no pressure on the low side and the needle just barely moved on the high side.

Can I just recharge the system, or do I need to go buy a vacuum pump and go through that whole process too? This seems like the next logical step at least. The FSM's only answer for no line pressure is replace the condenser, but that seems unlikely given the slow onset of the problem.

I'm not an AC expert but I'm fairly competent with a wrench so I'm just trying to figure out if this is something I can do on my own or not.

 

[Scottb4857]

Assuming you have the gauges on correct, no pressure means no refrigerant which equals a leak. The compressor will shut off when pressure starts to get low, but that doesn't just mean zero pressure. Most likely you'll need some dye along with couple cans refrigerant to charge it enough to track the leak. Since you're already there might as well test using the vacuum pump before charging. You can buy one or borrow one using autozone tool loaner program. Hook it up, if doesn't hold vacuum then you have verified you have a leak to find.
Depending on how long it's been empty you should also plan to change the dessicant in the condenser.

 

[ponytl]

You might just have a slow leak... the O rings where the lines join the compressor and the joint (large nut) to the right side of the radiator (follow the top high pressure line) are both places I'd look at for leaks... I'd drop 2 cans of 134a in (from dead empty they hold about 2.5) and see what happens... if it's a slow leak you can't find you might be ok with topping it off every year... my F350 is like that... for 6 years it's one can a year... the good is that you still have a minimum charge so it is holding some pressure... you my have to jump the compressor clutch with a hot wire to make it engage so that it will take a charge...

 

[tacoduck]

You might just have a slow leak... the O rings where the lines join the compressor and the joint (large nut) to the right side of the radiator (follow the top high pressure line) are both places I'd look at for leaks... I'd drop 2 cans of 134a in (from dead empty they hold about 2.5) and see what happens... if it's a slow leak you can't find you might be ok with topping it off every year... my F350 is like that... for 6 years it's one can a year... the good is that you still have a minimum charge so it is holding some pressure... you my have to jump the compressor clutch with a hot wire to make it engage so that it will take a charge...

this is where mine is leaking. I tightened the bolt and and hope it fixes it. next step is to replace the o ring in the fall if the pressure drops again...

 

[nissanh]

Tightening a joint like that is not going to help the leak. The O-ring is shot. Get AC type O-ring and put it all together.

 

[flintknapper]

Tightening a joint like that is not going to help the leak. The O-ring is shot. Get AC type O-ring and put it all together.

It will in this case, but not the way the OP had intended.

 

[tacoduck]

FML...

 

[flintknapper]

FML...

It's all going to work out.

Bummer at this point, I know, but it's going to get better. Hang in there.