Alright guys...I'm in need of some help. Application specific most likely. My truck is a 2001 4.0 4x4 140k on chassis. Got a little story so you'll have to bear with me.


When I needed to do my engine swap in mid 2009, I had the r134a pumped out prior to the swap when compressor removal was required. I unbolted the hard lines from the back of the compressor, did the swap, reinstalled without replacing o-ring. Only parts of the system I touched was that joint and obviously the compressor removal. Had it charged back up and it started blowing warm air within 5 days. Turns out a leak at the o-ring at the back of the compressor was the apparent culprit according to my Ford dealer. They replaced it and recharged the system. 7-10 days later she was blowing warm air again. No leaks were found at the dealer using the black light and the leak detector too..but the system was empty. They sort of refused to continue to help me without charging me, so I put off solving the issue due to dwindling funds being unemployed. Fast forward to fall 2011, I found a local guy that specializes in doing A/C work as his side gig. Evac'd the system and recahrged the system. Did a good leak check and it passed. 7-10 days later, warm air was blowing again and took it back to him. During this time the truck accumulated at most 20 miles. The system was empty again and he recharged it at no charge to me. A VERY thorough leak check using the light and the detector yielded no visible leak. But he advised possible bad dust caps so we removed those. 8 days and 10 miles later, all was gone once again. This brings us up to present day.


I've dropped nearly $300 in evac and recharges so far and every place I've taken it to can't give me a solid reason for the constant slow leak-out. I don't want to start replacing parts like crazy without knowing....A/C stuff gets expensive.


Is there any known problematic areas on our trucks where leakage is prone?? Could the valve cores in the fill/vent spots(where dust caps go) be faulty? Could it be a slow interal leak in the compressor not visible from outside the casing? Does the freon ever make it into the cab? The only issue is the fact the freon leaks out....it's not a faulty compressor switch.


I'm still very green when it comes to A/C systems, so anything you can tell me will help me. I'm currently in process of trying to find a localish specialized shop to work on it for me...but all I'm coming up with is "repair-all" types of shops and word of mouth is lacking.


Thank you for your time and info.


Shane

 

I'm surprised none of the shops used an electronic leak detector. Black light & dye wont usually disclose a leak in the evaporator short of dissembling the evaporator box.

Normally, when a customer has a repeated loss of refrigerant a thorough check of the system would be warranted to include fully evacuating the system, letting it site to see if the vacuum rises beyond a set rate, which would indicate a leak in the system. If no vacuum leak is detected during the evacuation, it would be charged up, run through its paces, and a second leak check would be conducted using an electronic detector during and afterwards to locate the leak.

 

sounds a lot like a problem we had with a car at work...IIRC it was the shrader valves that were leaking

 

When the guy charged it up at your A/C shop, I'm assuming he used a machine. When he drew a Vacuum on it, how long did he hold it for? If there is a leak in the system, usually a Vacuum cannot be drawn on the system, and if it is, it won't hold at a steady rate after like 3 or 4 minutes.

 

How much does 134a cost? I get those recharge kits at work for free occasionally, if you want i could remember to snag some for ya.

 

All good advice. What say you, Shane? I have some things to add depending on your answer.

 

Last time i saw some at the store, i want to say it was $15 - 20 for like 12 oz of it.
IIRC, Rangers take about 1lb - 6oz of R134a

 

Thanks everyone with your replies! This week has been crazy so I'm sorry for the delayed response. I'll answer some questions within the quote replies.




There was an electronic detector used. For sure was used with the side-gig guy who last worked on it because I watched him use it. Believe he had a movable tip/wand type. I don't know if Ford used it.

I don't recall seeing my local guy checking for a leak with the system evacuated. If memory serves me correctly, he pumped what was there out, then pumped new stuff in. Then checked for leaks. My theory of his process is that it'll have the dyed refrigerant in it, thus making leaks easier to see(black light) and detect(electronic). When Ford had it's shot, I wasn't in the shop when the work was being done.


Aside from process of recharge, any thoughts on my suspected list of possible causes? Thanks Rev.


It's been a while since I've last had it worked on, but I believe he pumped any "old" stuff out then called it good...and start pumping new in.


Shipping would kill it (if legal to ship) and I'd like to get the problem fixed rather than keep throwing refrigerant at it. lol.


What? Am I on The Factor???? hahaha. See above. lol.

 

When he was using the leak detector, did he check around the passenger floor boards right under the dash. That's where I found the leak on my truck, turns out the evaporator was leaking and that's when I said ---- it and removed the ac system. I'm not gonna tare my whole dash apart just for some ac.

 

Colorado you probably don't have to. haha. Where I'm planning on going, A/C is a requirement. lol.


He never went inside to check anything. In my opening post, I asked if the freon ever made it into the cab because I suspect it may be a suspect area to look into. I have noticed my jute under the vinyl floor has always been wet...not just in the passenger floor board. I get pretty hardcore when I pressure wash under the truck. lol.

 

I was going to say the same thing CO has nothing on the south. Its practically mandatory unless you want to swim in sweat all summer lol.

Did you check the compressor itself? I had a leak on it. Might of damaged it and not realized it?

Btw off topic, but where are you going?

 

My old trucks floor got wet on the inside like yours is, i believe it was the door trim on the very bottom, the screws were replaced and never sealed right.

If there are no line leaks, i'd say check the components then, Such as Compressor, condenser and evap canister. I feel like if it was leaking when you had it running, you'd hear or see the freon shooting out of it.

 

If it was visibly leaking, it won't be working properly and cold for 7-10 days, it would be blowing warm within a few hours.

 

I had to replace the condenser on my '03 last year. It actually leaked the A/C oil out of the bottom and was found collected in the plastic cover underneath the radiator/condensor area under the truck. Almost looks like green antifreeze but oily and I'm sure some of it was the dye from when we tried to diagnose the leak. While it was all apart we replaced the O-rings though out the system, the condenser, and the accumulator/dryer (whatever its called) with all new Ford parts and had my mechanic neighbor take it to his shop and do a full vac down and recharge with new oil. Been perfect ever since. In this case, the system lost its charge quickly...wouldn't hold for more than a day. Never was sure why the condenser suddenly started leaking...must have been a bad solder or something on one of the coils from the factory that finally let loose.

The sniffer tool was kinda unreliable in this case because it was leaking out of the bottom of the condensor. Checked all the lines, behind the A/C compressor clutch, around the evaporator, etc. and found nothing. Just by chance I noticed the green oil dripping out of the truck from the very bottom. I did learn quite a bit about car A/C systems doing this work so it was positive in a way. I'm certainly no pro by any means...haha...but it is kind of interesting how simple yet complicated the systems are.

 

The A/C in my ranger leaked down at a similar rate until I added leak stop to it. I'm in the hvac/refrig biz and decided to give it a try. Its been chilly cold for 4 weeks now.
http://www.nucalgon.com/products/tot...ACEasySeal.htm

 

Thanks for your posts guys. I've just gotta find a way to get the truck that doesn't get used to a shop during the hours I work. lol.