Wednesday, March 14, 2012

Mercedes benz Fill Transmission fluid

VEHICLE: 2009 Mercedes-Benz C300 4Matic Sport 3.0L, V6, MFI, DOHC, Eng Desg 272.948

MILEAGE: 80,000

Problem How is transmission fluid filled after service? There is no fill tube.

Tests: 1.
Identify the transmission type. If the transmission has a fluid fill tube without a dipstick, the transmission is a 5-speed 722.6. If the transmission has no tube, it is a 7-speed 722.9.

With a 722.9 transmission, it is required to fill the transmission by using the drain in the pan. When the transmission pan is removed and filter replaced, start by adding 4 1/2 quarts and start the engine.

Use a factory type scan tool to read transmission temperature. When at 40 deg. C and not more than 45 deg. C, fill fluid into the drain hole. Remove the tool and watch for the amount of fluid that drains out. With no fluid or a small amount draining back out, the fluid is not full enough. With large amounts of fluid draining out, wait until the stream is reduced to the size of a pencil.

Potential Causes: Information Only

Confirmed Fix: Performed Automatic Transmission Service: 5.5 liters

Tech Tips: Special tools are required to fill the transmission. Always use factory fluid. Always replace the transmission pan bolts and follow the torque procedures or they will break.

How to fill mercedes benz transmission fluid


  1. Good information. A 722.9 is too difficult for a DIY - requires specialized equipment.

    1. Not that hard. There are plenty of tutorials on how to do a full flush on a 722.9. Only special equipment is a pump and a fitting that are readily available and inexpensive.