I tried a retrofit kit on my 92' f-350 (351W), changed the oriface tube and drier. Flushed the system, and added 3 cans of 134a and 1 can of oil. It all leaked out in a couple of days. So I added 2 cans of freon, 1 can of leak finder/sealer, and another can of oil. Well after leaking out again, I tried a two part system from Wal-Mart. 2 oz of metal parts sealer, 2oz of o-ring sealer. Added another 2 cans of freon and a 2 oz can of oil. Well it's holding 45 psi on the low side (ideling), But it's only getting to 76 F. Can I possibly have too much oil in the system.

Please help!
Scott C.

 

If the system ever goes dry, you will have to have the system evacuated. That has to be done by a shop that does A/C systems. The system has to be under vaccuum to get the right amount of refrigerant into it.

You should have air about 42* coming out with R134a. I know the old R-12 systems could get down to 36-38*.

 

Does this mean I'll have to drain and evacuate the system, then try again?

 

You didn't see the leak-finder anywhere? That usually means it's in the evaporator core, and is dripping onto the ground. You need to find the leak FIRST, and then decide how to proceed. I'd definitely get all the oil out and make sure the right amount is in the system, especially considering the O-ring "sealer". All it does is attack the rubber, causing it to soften & swell. It may seal a small leak for a little while, but it makes ALL the seals in the system degrade faster. I'd never use it again, in ANY system (like the power steering crap).

 

If you have access to a bottle of nitrogen you can pressurize the system, then, using some dishwashing soap diluted with water, apply the mix to the joints. If there is a leak, even a small one, it will develop foam/bubbles. Give it some time, say 5 minutes, for bubbles to appear. Do NOT run the a/c with the nitrogen in the system. If you have an existing leak, you should also see traces of oil around it. Proceed to repair the leak. Because O-rings are dirt cheap, you may just want to replace all of them. Note: the soap method may not find a VERY SMALL, ITTY BITTY LEAK, but if you're loosing all of your charge in two days, it's def gonna show. I can also say that the fancy, expensive sniffers do miss these itty bitty leaks too. The itty bitty leak I'm refering to is one that drains the system in, say two+ years. After repairing the leak(s), repeat the presurization with nitrogen followed by soapy water to ensure that the system is leak free prior to evacuation and charging.

I'd also do as mentioned and get the sealers out of the system, and the correct type and quantity of oil in it. Ditto on the dye.

Because air does not condense in a/c systems, it therefore will not boil, which is required for a/c to operate. It's the boiling of the refrigerant that absorbs heat. If air is in the system, you may see erratic/wandering pressures, esp on the high side. Therefore, you must get it out prior to charging. I know of ways to get the air out of a system without a vac pump, but do try to borrow/rent one as it's preferrable. Evacuate for 10-15 minutes. Prior to shutting off the vac pump, close the valve on your gage set leading to the vac pump first. Note the gage reading and let it sit for an hour or so. It should not change; if it does it means you still have a leak somewhere that must be fixed. Note that before introducing refrigerant into the system, you must purge the line from the refrigerant can to the gages with refrigerant; just loosen the line a bit at the gages and let a good puff blow through the line, then tighten and proceed to charge.

 

Couldn't find the dye. I thought it would be easy with a leak like this. I guess I'll have to rent a vacume pump. Well I guess it's back to the old shade tree. Thanks for the help.

Scott C.