HIGH SIDE LEAK
Note: Click here for a related training video (Located at the end of this article)
Now that you have accurately diagnosed the issue with the sealed system, click the below button for Sealed System Repair Contents:
If the unit has a High Side Leak you will find your Low Side pressure and High Side Pressures will both be lower than normal. Amp Draw and Voltage will be normal to below normal. There will be No or Partial frost pattern depending on how much refrigerant is remaining in the system.
The High Side of the system is made up of the Discharge Line, Condenser, Yoder Loop, and Capillary Tube.
When your run pressures indicate High Side leak it is recommended to pressurize the system to 200 PSI and bubble check all the High Side joints and leak points if the leak cannot be heard or easily found.
Be sure and test the lower portion of the condenser coil that routes into the drain pan for corrosion and test the factory compression fitting that joins the Condenser coil to the Yoder Loop.
Below are common places to check for High Side leaks while the system is pressurized…
On models with the steel condensers, it was possible for the steel to rust and form tiny leaks in the drain pan area as shown in the below picture:
If no external leaks on the High Side of the system can be found, then the internal Yoder Loop can be tested.
To properly test the Yoder Loop, it needs to be fully isolated from the rest of the system and pressure tested. Isolation example below:
In some cases, the Yoder Loop can be repaired depending on where exactly the leaking is located….
See Article # (20150125133427) for repair info where the yoder enters and exits the cabinet. And (20150113949139) for repair info on yoder loop leaks found in the mullion area between the freezer doors on dual freezer drawer models.
For units with confirmed Yoder Loop leaks there is often external identifiers that point to the yoder being rusted or leaking. Check the cabinet seams around the front of the unit where the yoder is routed for these visual signs. Example:
Now that you have identified the issue with the sealed system and made your repair make sure you achieve a proper vacuum before recharging the unit.
The reason for pulling a deep vacuum is to make sure the system is leak free and all moisture and non-condensables have been removed from the sealed system before recharging the system. This should be performed on every sealed system repair and every time the sealed system is opened for any reason.
The industry standard for a proper vacuum is to reach 500 microns. But don’t stop there…. By monitoring your Micron Gauge you can learn valuable information about the sealed system.
Once you reach 500 microns, isolate the system and micron gauge from the vacuum pump and watch your micron level to see how far it rises. To do this you will need an isolation valve between the vacuum pump and micron gauge:
- Once you have reached 500 microns and isolated your pump what happens next will tell you if you still have issues within the sealed system. It is important that you analyze the micron level for 10-15 minutes after isolating the pump and look for the below conditions…
1) If the micron level rises above 2000 this is an indication that there is still a leak somewhere in the system. Locate the leak, repair, and pull vacuum again.
2) If the micron level stabilizes between 1000-2000 microns this is an indication that there is still moisture/non-condensables in the system. If this occurs, you need to pull your vacuum longer until the micron level stays stable under 1000. (Tip: If there is moisture/non-condensables in the system you can purge the system with nitrogen to clean the system quickly then pull your vacuum again.)
3) The goal to know that you have a leak free and clean system is for your micron level to stabilize below 1000. If you achieve 500 microns and stabilize under 1000 you are good to go ahead and recharge the system like the example below:
Note: If you are having trouble achieving 500 microns make sure your equipment is not the issue. Maintaining your vacuum pump oil, micron gauge, and manifold gauge seals / hoses is very important. If your equipment is in question, try pulling a vacuum on the equipment itself to see if it can achieve and hold proper levels.