AC start/stop every few seconds

[Blk00ss]

You can also look for leaks at the connection/o-ring locations and at the crimp fit of the hoses. When it does leak, a/c oil will come out with the refrigerant and those areas will be wet and attract dirt that will gather and cling there and show as wet looking dirt.

I've seen this with one of our old vehicles too. I did check the hoses on our Tahoe and didn't notice anyting. I've never charged a system, but I think I'm gonna try. I mean honestly, if I take it to a mechanic they're gonna charge me a lot more to charge it then it would cost me. Wish me luck!

 

[OR VietVet]

Since I don't have a refrigerant charging station or at least a vacuum pump anymore, if I do a/c work and it has refrigerant in the system, I take the rig to my friends garage, he recovers the refrigerant in the system, I do the work needed and then take back to him to do the vacuum and recharge.

 

[BoatyMcBoatface]

I went online and ordered metal shrader valve caps that have an o-ring. Hopefully this will slow or stop the leak on the low side. I have changed the schrader valve but same thing happens after a few years.

 

[OR VietVet]

You can do the caps with o-rings, all caps have the o-rings if I remember right, but the pressure will seep past those o-rings over time. The shrader needs replaced periodically.

 

[rockola1971]

I went online and ordered metal shrader valve caps that have an o-ring. Hopefully this will slow or stop the leak on the low side. I have changed the schrader valve but same thing happens after a few years.

The typical leaks of a well used system are at at the orings on the hoses that attach to the condenser and/or compressor. Cracked evaporators. Damages to hoses. Leak at TXV valve body for rear A/C and the stereotypical gremlin that never seems to go away is the leaking front seal of the compressor which requires a rebuild or replace. The system has a high and low pressure safety switch. The compressor is lubed by lube oil that is mixed in with the refrigerant. Anytime you have a leak, you lose both refrigerant and lube oil. The low pressure switch saves the compressor from self destruction once a major leak happens and the pressure gets low enough. The reason the compressor is cycling is because the pressure increases (above the low pressure switch cutoff) because the refrigerant is absorbing heat which causes the pressure to rise. Then the compressor kicks on and the pressure lowers as the system discharges the heat out of refrigerant at the condenser. The low pressure switch shuts compressor down (disengages compressor clutch) and then the cycle happens all over again. You are right on the threshold of being very low on refrigerant. If leak requires system to be opened up I would get a complete evacuation of all old oil. Install a new oil complete charge with refrigerant. If the system is just being topped off I would add a oil charge which can be bought mixed with refrigerant. Winter time is the cheapest time to buy refrigerant.

 

[Blk00ss]

Can the accumulator tank itself leak at the weld that goes around the circumference of the tank? Today I noticed green film around the weld of the accumulator. Is this a common leak on these vehicles?

 

[OR VietVet]

Anything can leak from anywhere but I would suspect a leak from above there.

 

[Blk00ss]

Anything can leak from anywhere but I would suspect a leak from above there.

Thats exactly what I thought, but its weird because the substance I'm seeing (neon green and oily) is almost symmetric all the way around the accumulator. And there isn't really anyting above it really. I did chnage the low side sensor. It dind't fix the issue because I'm certain its low on refrigerant which is causing it come on and off anyways. Hate to refill only for it to leak right back out. I'll have to investigate more I guess