A/C Expansion Valve replacement

If the A/C in your Sprinter doesn’t blow cold anymore an/or the compressor is noisy, the culprit might be the Expansion valve. This little device controls the amount of refrigerant that enters the Evaporator. Or in tech speak:

The expansion valve removes pressure from the liquid refrigerant to allow expansion or change of state from a liquid to a vapor in the evaporator. (Source)

If you have the tools to measure the pressure in your A/C lines you can figure out quickly if the Expansion valve is broken:

  • If the low side pressure of the A/C system is too high and the high side too low.
  • If the low side is too low and the high side pressure is too high.

The Expansion valve is located at the dash panel between the A/C refrigerant lines and the evaporator. Replacement of the Valve is quite easy although the access is a bit restricted by the windshield wiper mechanism.

Location of the A/C Expansion Valve in the engine compartment.
Location of the A/C Expansion Valve in the engine compartment.

You’ll need to start with the nut that holds the right hand side A/C lines in place (#6 in the picture below). This I’ve found was the most tricky part of the whole job since you can’t get a wrench between the two A/C lines so the only option is a small Ratchet with an extension.

Expansion Valve Details
Expansion Valve Details

After you have pushed the A/C lines on the right a bit to the side you can start removing the two bolts (#4) that attach the left hand A/C lines. These bolts have Allen heads, so be careful not to strip them.

Allen type bolts on the Expansion Valve for one side of the A/C lines
Allen type bolts on the Expansion Valve for one side of the A/C lines

Now you can remove the Expansion Valve. To install the new one just follow the steps in reverse. The replacement part that I’ve got didn’t have the bolt for the right hand A/C lines so I had to fabricate that myself by removing the head of a matching screw. You’ll also need to replace the O-rings with new ones that should be lubricated with clean refrigerant oil before installing them.

Parts needed:

  • Sprinter A/C Evaporator. Part Number: A9018300084 or 05143304AA

Tools required:

  • Rachet with extension
  • Wrenches
  • Allen bit

Torque values:

  • Allen bolts: 5 Nm / 45 inch lbs
  • Nut: 10 Nm / 89 inch lbs

 

Summary
  • 2/10
    Technical Difficulty - 2/10
  • 2/10
    Time needed - 2/10

3 thoughts on “A/C Expansion Valve replacement


  1. just wondering if the expansion valve in the sprinter meters refrigerant by sensing pressure in the evaporator or by temp


    1. it works by temperature. here’s what the service manual says:

      High-pressure, high temperature liquid refrigerant from the liquid line passes through the expansion valve orifice, converting it into a low-pressure, low temperature mixture of liquid and gas before it enters the A/C evaporator. A thermal sensor in the A/C expansion valve monitors the temperature of the refrigerant leaving the A/C evaporator and adjusts the orifice size at the evaporator inlet to allow the proper amount of refrigerant into the A/C evaporator in order to meet vehicle cooling requirements. Controlling the refrigerant flow through the A/C evaporator ensures that none of the refrigerant leaving the evaporator is still in a liquid state, which could cause damage to the A/C compressor.

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