Refrigerant Type: R12
Country of Origin: United States
I am still stumped by this truck's leak. Which is is only apparent AC problem.
I have replaced all the o-rings, and OE accumulator. Won't hold a vacuum for even a couple minutes.
Put UV dye in and charged to about 18-20 on low side while running (compressor worked perfect, no noise). Ran for almost 10 minutes. No signs of leak anywhere with UV light. This system is highly exposed so it's real easy to see all the lines etc...Held pressure at 70psi static for almost 2 hours, came back 2 more hours later and it was empty. Looked again with UV light, no dye anywhere.
Looked again today and I can see no UV dye anywhere visible on condenser (can't see back side), all lines (even peeled off foam on low side from evap to comp) connections (only 1 spring lock connection, evap inlet), compressor case and shaft seal. I then pulled evaporator (easy 20min job) think it has to be the only place left to leak. I could see dye inside both lines, but no dye anywhere external.
This is a huge leak and I can't believe there are no signs of the dye leaking out. I might have to go get someone to use an electronic sniffer to find this leak.
Any other suggestions?
Probably the infamous Ford spring-lock leak. You're probably not seeing any dye - yet - because it's accumulating on the garter springs where it's not easily soon. Shine your light on the springs (use a mirror if needed). If this system was operational, you'd see the dye and oily mess in short order.
I bet worst of the leak is at the evaporator fittings. O-ring changeout is not enough, the female fittings need to be polished out perfectly smooth. If that's not possible, the item(s) in question should be replaced.
Also, pull apart the radiator from the condenser so you can get a view of the back side of the condenser.
In many cases, dye finds what is sometimes not found by sniffers.
If it's a connection leak(s) that leaks down to zero in 4 hours, you can find that with static pressure and soap bubbles. Put a test gas (dry air, nitrogen, MIG welding inert gas, or R-134a) in at 20-30 psi. You should have plenty of leakage at that pressure. It's good practice not to charge an R-12 system until after it has passed a pressure test with some other gas.
Edited: Wed July 13, 2011 at 10:35 PM by mk378
When I got the truck it had zero charge, and the PO had never touched it in the 2 yrs he had it. I first did a visual inspection of everything but evap, not a trace of oily residue anywhere from old leak. Did leak test with 50psi static 134a and soapy water and couldn't find anything. That's when I changed all the o-rings. Did same test, no sign of leak, but it all leaked out in about 45 mins both times.
The next step is what I described in first post with the dye.
I installed the new accumulator today and inspected the evap connections including the spring-lock one on on the inlet when I removed the evap for inspection. and no sign of dye. I did make use of a mirror, and the ONLY place I have not shined a UV light on is the back side of the condenser.
This truck will basically leak out a full charge in 2-3 hours. WITH NO SIGN OF DYE?!?!?
I definitely plan on making sure it holds pressure with r134a or something before I even think about putting in R12.
There is approximately 3,500 drops in a cup of oil, if dripping slowly, really hard to fine, but if you lose not even half of your oil, compressor can seize up. And yes, you can lose oil without refrigerant. Opposite is also true, can lose all of your refrigerant without a sign of any dye or oil leaks. You have to believe both are possible including losing a percentage of your refrigerant and oil. Those percentages can vary all over the place.
In a vehicle with AT, coolant, oil, PS, and brake fluid combined with refrigerant oil, have to be able to tell the difference. Not easy in an older vehicle that is no longer showroom new. Electronic leak detectors are really the only means to detect refrigerant leaks, but beside having a good one, requires a deal of skill to use one. But these aren't any good with a very tiny pinhole leak in a condenser or an evaporator. Have to remove those, drop in a clean container of water, hit it with 140 psi of pressure, then you can see the tiny air bubbles popping out.
My kids' HVAC guy finally got a leak detector, I took mine out on a windless day and found leaks, he comes out on a 30 mph wind day and claims no leaks. But yet the system is leaking out in a couple of day, what an idiot. Son is ready to take this guy to small claims court and get a refund. Told him already would cost 1,800 bucks just for parts and will be happy to install it, the right way. He is kicking this around.
Vacuum is not a sign of a leak proof system, puts negative pressure on the compressor seal and service ports, a good guess if that is the problem, system has to be under pressure. Temperature also plays a role, particularly in joints. When cold, metal contracts that can close a joint leak, but leaks like crazy when hot.
Sometimes, just easier, and really not that expensive to install a new system if you do the work yourself, you are dealing with a 20 year old vehicle that wasn't that good in the first place with those crazy spring-lock couplers depending on two O-rings between two tubes to prevent leaks. The dealing with R-12 that is extremely expensive, but R-134a isn't exactly cheap either anymore. R-410a is also crazy as well as R-22.
Welcome to the area of AC repair.
Well I had to take the truck up to Meineke for a $19.95 sniffer leak test. He found it was leaking from the compressor seal. Had almost undetectable traces of dye, but the sniffer went crazy.
This might explain why it actually held some pressure after I ran it for a bit when I was adding the dye.
Old seal decided to seal for a while when it actually had something to seal in.
Any help on tricks for replacing the seal on this '93 Ford F250 with a FS10 compressor?
Here's the O'reilly image of it
Edited: Sat July 16, 2011 at 11:33 PM by jga2z
Using dye is, in my opinion, a waste of time. An electronic leak detector will find very, very small leaks and does not require the time/cost to add a dye to the system and then wait for it to show up.
Grove Automotive Group, Inc.
An Alabama Corporation
If your compressor is a FX15 you need to get it away from the truck and never look back, it's the black death model. The FS10 that replaced it is also pretty much a throwaway unit not worth tinkering with when it's that old.
I don't do enough AC leak detection to justify buying an electronic leak detector. So I got the AC tech at Meineke to ck for a leak.
He found a front compressor seal leak.
I can't afford $200 for a new compressor so I changed the front seal then pulled a vacuum for 40 min. It held for about 30 minutes fine
So I went ahead and charged up some till vent temp got down to Next morning it was empty
So I guess I have another leak elsewhere. I talked Meineke into looking again for the elusive leak at no charge. Updates to follow...
Well the result of the 2nd sniffer test was, the case is leaking from the center seam. I don't think it was ever leaking from the shaft seal since both times the sniffer went off on the top of the compressor and behind the pulley, not the front by the clutch which is the only place it can leak out if it's the shaft seal.
So now I went and got a used one at the salvage yard for $50 off a '99 Expedition w/110k miles. I didn't go $180 for a new one since the warranty is no good unless I buy an accumulator and O-tube at the same time. Never mind I just bought them just a month ago and the system has never worked yet.
I am flushing the replacement compressor since it had PAG oil in it and I still plan on R-12 in the truck when all is said and done.
Still trying to decide how much oil to add back in with just the compressor change. I added 2 oz to the old compressor when I changed the seal and reinstalled it.
The clock is ticking, I'm headed to the lake with camper in tow on Friday. If you're wondering how I can afford to go to the lake but can't afford another $130 for a new compressor. It's simple, I pay nothing for fuel, I run waste motor oil for fuel in my Ford diesel.
Edited: Wed July 20, 2011 at 10:54 PM by jga2z
As MK378 mentioned, you do realize the FS-10 is pretty much a disposable compressor... and at 12 years old and 110,000 miles I'd say that FS-10 is on the disposal short list. I wouldn't worry so much about a warranty, as I would the quality of the compressor ($180 doesn't sound like new), because if an FX/FS compressor goes, it takes pretty much everything with it.
The original compressor with 217K and 18 years still worked fine except for the case leak.
I don't plan on using this truck more than a couple thousand miles a year so I think the AC will last me a while, knock on wood.
I pulled a vacuum for 45 min tonight and it held for 4 hours. With a near empty 30# R12 bottle got 35 psi in the system. Am going to charge up tomorrow.
Every time I read a thread like this I cringe.
Junkyard parts, waste motor oil for fuel...
I wonder what the braking system looks like on this 7500 pound rattletrap? Suppose it has a pair of rotors that are .150 below minimum thickness? Junkyard pads from 3 different trucks? Paperclip instead of a cotter key?
This kind of stuff is out there folks. It is behind you on the lake road, loaded to the bump stops with a boat trailer behind it.
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.
How do you know if the vehicle the compressor is coming off of has been run for an extended amount of time with a low charge and slightly starved for oil. Or what if it just kept being topped with R-134a due to springlock leaks, as the oil keeps running lower and lower? What if a WalMart recharge kit was used and has some nice sealer and who knows what else in it?
If all you had to worry about was the compressor failing and just replace it with another one, no problem, but when it fails, what about all the other damage that will happen to the rest of the system? I don't think I'd risk a TSR over a used compressor. I just hope luck is on your side.
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