Dash AC line replacement?

[Scotty Hutto]

I have a leak in my low side refrigerant line for my dash AC. AC Tech has spent hours climbing up and down the frame rails (and didn’t charge me) trying to find the leak. At present, based on leak detection dye and sniffer, he suspects the rubber-to-metal fittings where the lines connect to the evaporator.  
 

Has anyone replaced those fittings on the existing hoses before? Can that be done by someone with proper equipment?   The location is easily accessible with room to work  

Has anyone replaced their dash AC refrigerant lines before? 
 

Any experiences or thoughts are appreciated as I decide how to tackle this problem. 
 

Thanks,

Scotty

[DavidL]

the tech needs to be conclusive that he/she found the leak location.  Still sounds like its fuzzy.

 

[Frank Bergamo]

Scotty,

I replaced both the high and low side fittings on my ‘02 Beaver at the compressor pump with custom made fittings made at Cold Hose in Florida. https://coldhose.com/ Used heavy duty bolt clamps to connect at rubber lines. If you have to cut off existing fittings, the new ones might need to be made longer if you don’t have enough slack in hose. You might try to find someone that can crimp the new fittings on your line if you have room to work, instead of using bolt clamps to secure new fitting. After installing new fittings, ran coach for 2 years before selling, without having to recharge system. Hope this helps.

[Pampero]

I will look carefully to the condenser on the back of the coach.
Aluminum condenser are prone to rot. If he put dye in the system it should be easy to spot with a fluorescent light and glasses.

[Guest Ray Davis]

 He, Scotty thinks the leak is up front because he mentioned evaporator.    I don't know, but it should be a little easier to repair in the front since   his radiator is in the rear.         

 However like David said I would want a better diagnosis before cutting the hoses.

 What is the A/C doing?   A slow leak might be tolerable and a fast leak should have been easy to locate.  Many R/Vs seem to leak a little anyway, I   add a can about once a yr or so. 

 Replacing the hoses would be a big job.  Mike , ( zmotorsports ) on IRV2 replaced his heater hoses and said it was the worst job ever. Here is a post   from there

 

Originally Posted by Burgy  Well can't wait to your video on the air bag job, will be almost as fun as doing the heater hose change out

" I hope not. That was hands down the worst job I remember doing, and I've done some real **** jobs in my days of wrenching."

 

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Edited March 14, 2021 by Ray Davis

[Hypoxia]

5 hours ago, Scotty Hutto said:

Has anyone replaced those fittings on the existing hoses before? Can that be done by someone with proper equipment?   The location is easily accessible with room to work  

Normally you would crimp a new fitting on a new piece of hose and then crimp that to the old hose.  Sometimes there is a proprietary fitting that has to be re-used and is welded to a new fitting on the new hose, I had to do that on my compressor fitting.  Crimping a fitting on an old hose comes with the risk it will leak, but worth trying, mine has not leaked. 

My heater line is a metal pipe from front to back with heater hose on each end.

[trailmug]

The suction line from the evaporator to compressor is probably most reasonably field assembled because of the length, twist, turns, etc (Monaco appears to have assembled the entire system with a manual crimper). I suppose you could feed a wire/string down the old hose to measure the length (and measure the fitting "clock" angle) and have one made if you think you can get right angle fittings through all of the passages. All of the OE-validated refrigerant lines these days are reduced-diameter and engineered as a system. I tried to source Parker's series 1A fittings to field-assemble 285 hose for a validated solution (what I would REALLY want for this), but was unable to find them. I presume what you're working with is #10 standard diameter barrier hose. If find yourself needing to crimp onto an old standard diameter hose, I highly recommend Gates fittings.. NAPA can order them. I have had multiple MEI Airsource-sourced fittings leak after assembly. I have a MasterCool manual crimper you are welcome to borrow, if you like. For any of the shorter runs, like from the receiver-dryer to the evaporator, I recommend taking the old hose to a Parker Store and letting them fab one for you with a hydraulic press. It's expensive ($100) but worth knowing you have a good hose assembly. My leak was at the high side service port, and I ultimately had Parker make me a 2 ft hose terminated with MIO fitting, and then crimped my own service port / o-ring fitting onto the old #8 hose (1 manual crimp vs 3). Fortunately, they had the special "Tube-O" fitting needed to connect to the compressor head.

A refrigerant sniffer is not very expensive and works better than UV dye in my experience. Got to be careful with UV dye as mineral oil-based dye will wreck a PAG-lubricated system (I believe this happened to my coach).

I've been through nearly a full system replacement, except for the evaporator and the long lines, if you're looking for someone who cares way too much about dash air and thinks he knows everything (I actually ended up with an EPA 609 cert out of this).

Take care and good luck with the repair,
Rob

 

Edit: If the system has gone completely flat, you would ideally replace the PAG oil in the compressor crankcase, as it is hydrophilic, and you definitely want a new receiver/dryer and another couple oz of oil to go in that, and new HNBR O-rings to go on anything you take off.

 

Edited March 15, 2021 by trailmug