This is how we do it. We know it works the best. With the E-46, E-47, E-57, it is OK to change the fluid with the unit on the truck, and better to take it off and change the fluid in a vise, but on the vehicle is OK. We will explain more about why later.
First get yourself a drain pan. I take my wife’s old pots and pans to the shop, no sense in wasting them. You need a pan that will hold around 2 quarts minimum. Larger is better, as there is room for splashing and sloshing without making more of a mess…
Go in the vehicle and turn the ignition on. Walk back around front, and manually push the Lift Arm ALL THE WAY DOWN. Go back inside the vehicle and turn the key off. Use a 5/8″ open end wrench to remove the Fill Plug / Vent Plug, and Bushing. The Bushing is 5/8″ and the Vent in it is 7/16″. It is a little easier putting new fluid in with the whole thing removed rather than the tiny hole in the Bushing that the Vent screws into. Removing the Vent will allow the fluid to flow out without “glugging” and making a mess.
You can see in the above Meyer E-47 picture that there is a Drain Plug. Early E-47 units did not have Drain Plugs. IF yours has a Drain Plug, skip the next paragraph.
IF yours does not have a drain plug, the only way (short of disassembling the unit) to get the fluid out is through the fill hole. First disconnect the power wire to the motor, and the ground wire to the back of the unit. Unplug your 3 coil wires (red, green, black). Next you will want to remove the 5/8″ bolt that holds the pump to the Lift Arm. Now you can tip the pump down over your drain pan. In this case, the fluid will “glug” while coming out. There is less than a quart of fluid in the unit. IF it is an H Model, there will be about 1.5 quarts in it to drain.
Loosen the Drain Plug using an 11/16″ box end wrench or socket (some early units you will need a 5/8″ wrench or socket). You may have to screw it back in and then out a few times to break the O Ring free. Take your time, and do not tear the O Ring. Once you can turn it with your fingers, get the drain pan ready, and slowly remove the Drain Plug. The fluid will drain quick. then slow to a trickle, and you will see the black gunk flow out, and any water that has not mixed with the fluid. IF you have the unit in a vise, you can tip it forward more to drain even more out. Then remove the two Filter Plugs and Filters. Clean the filters with kerosene, and gently blow them out with compressed air if you can. The Filter on the right in the picture is the High Pressure Filter. That means when the fluid leaves to pump, it must first pass through the High Pressure Filter before it gets to where it is going. There will not be any pressure behind the Plug when you go to remove it.
IF the fluid looks milky, or a lot of water comes out, then the source of the water contamination needs to be found and corrected or you will be left stranded when you need the unit the most. Better to take care of it now rather than later. The main sources of contamination are the Couplers (are they leaking fluid?) and the chrome on the Lift Ram, and Angle Rams. If they are rusted and pitted, the pits pull water into the system when using the plow. You will never win the battle with moisture, they need to be replaced, period. Remember where fluid leaks out, water often gets sucked in too. Having the unit rebuilt or rebuilding it yourself (if you are confident you can do it) is a good idea when water is found. If there is no pitting, a Basic Seal Kit will often solve your water problem. IF you have signs of water, the Angle Rams MUST be flushed too. More on that later…
Next is additional steps you can take to get even more gunk out of the unit, which is why you are changing the fluid to begin with. Put the Drain Plug back in finger tight. Put about a third of a quart of Meyer M2 Hydra-Flush into the fill hole. Let the unit sit for 15 minutes or so. Get your drain pan and remove the Drain Plug again. Even more gunk will come out. If you have access to a compressor, use a blow gun with a rubber tip firmly inserted into the fill hole, and a rag held loosely over the Drain Hole, and CAREFULLY, GENTLY blow air into the unit. This will push out more gunk. Repeat two more times, finishing the bottle of Hydra-Flush. Any remnants of Hydra-Flush in the system will not harm it. Put the Drain Plug back in, and torque it to 65 – 75 INCH Pounds. Put the Filters and Filter Plugs back in, and torque them to 65 – 75 INCH pounds. Refill the unit with Fluid. Use a zip tie, or bent piece of wire, or a popsicle stick as a dipstick. You want the fluid to be about 1.5″ below the top.
Meyer E-60 / E-60H
The E-60 is a little different. For whatever reason, the Drain Plug is right in the center of the bottom of the unit. When it is on the vehicle, it is tilted forward. Removing the Drain Plug will not get all the gunk out. This is why it is best to remove the E060 from the vehicle and change the fluid in a vise. See the picture below.
You can see how all the gunk settled to the left inside the unit in the picture. That is where it is level when the E-60 is mounted on the vehicle. To be honest, taking the the Motor and Side Cover (Motor Mounting Plate) off is the best way to clean out an E-60, but upright in a vise is the next best way.
Follow the steps outlined for the E-47 unit above. Remove the Vent/Fill Plug, then the Drain Plug. The difference is that you will need a 1/4″ Allen Wrench to remove the Drain Plug on the E-60. Another reason to remove the E-60 from the vehicle is that there is a Filter Plug on the back of the unit. It is typically not easy to get to when mounted on the vehicle. The other Filter Plug is on the front of the unit. There will be what looks like two Filter Plugs on the front. The one on the left is NOT a Filter, it is the Drop Speed Adjusting Screw. The one on the right is the other Filter. Follow the steps for the E-47 above to flush and blow out the inside of the unit. Refill as outlined above. The difference is that the E-60 holds over a quart of fluid, and the H Model holds almost 2 quarts. Better use the larger drain pan I mentioned above.
IF you only drain the hydraulic unit you are still leaving dirty, contaminated fluid in your Power Angle Rams. We put a couple of videos up on You Tube to show how to flush your Power Angle Rams.