AC HP Line Leak / Repair

[Paul Fithian]

I recently discovered the AC on our 2007 Sport Trac V8 was no longer working. A recharge with Chemours 134a with UV leak detector revealed the leak was coming from the high pressure line to the condenser.

I ordered a new seal for this connection, any tips on replacing? From what I have found, this vehicle's AC system needs 9 ounces of Motorcraft® PAG YN-12-D oil and 31 ounces of R-134a.

 

[Rcflyer330]

If you are just replacing the seal you probably don't need to add any unless you are replacing a major part for example condenser, compressor, evaporator, system dryer... etc. some refrigerant kits have oil already in them so its a good idea to check the labeling. also if you don't have a vacuum pump for the ac system take it to a shop so they can properly vacuum it down and charge it correctly. The sticker on the hood or radiator overflow bottle will tell you the correct oil type, oil amount, refrigerant type (r134A), and amount for your vehicle.


I may be wrong on the adding oil I am not a ac tech but it is what a have read and seen done by mechanics.

 

[Fix4Dirt]

if you replace the seal, not an ac guru, but i thnk you need to discharge then recharge the system before & after the change, so refrigerant+oil imo.... but then again, not too sure

 

[Bazz270]

As per workshop manual ,in case of oring only, you should discharge the system,fix the seal and add 60ml of the PAG46 ot motorcraft PAG oil during the charging operation.

Just to be sure

This hoses usually failed first in the rubber hose crimp location .are you sure about the oring leak only?

 

[Paul Fithian]

Thanks Bazz, you are correct. I had another look, there is a leak at the hose crimp. I have ordered a new line, Motorcraft YF3627.

Any advice on how much oil to add after replacing this line?

 

[Bazz270]

The same amount of 60ml

 

[Bazz270]

By the way

All the motorcraft HVAC lines supplied with new seals and orings.you dont need to purchase em separately.

Mine leaked both the high and the low charge lines crimps

Torque to specs and use threadlocker:

 

[JustinGibson]

If you have an O'Reilly auto parts nearby you can rent the gauge set and vacuum at no cost. Put a vacuum on the system for about an hour. It should go down to about 30 hg iirc to boil off any moisture. Close the valves on the gauge set and let the vacuum hold for 30 min. If it holds you should have no leaks. Put the 60 mL of oil in the refrigerant hose hook it back up and add the required amount of refrigerant.

Make sure the seals that come with the gauge set are good and lubricate them with some of the pag oil.

 

[Paul Fithian]

Thanks Justin, I have a gauge set and vacuum pump in my shop.

 

[Paul Fithian]

I was able to install the new high pressure line this weekend, it snakes under the compressor and is held by a flange bolt and clamp on the bottom side of the compressor. Easy access from the right front wheel well with the front splash shield removed.

After evacuating to -30 in Hg and confirmed that it held overnight, I charged the system with 3 oz of Motorcraft® PAG YN-12-D oil & 31 oz of 134a.

All good, now blowing cold air. Thanks for the help!