DABENZER
New Member
Right guys,
Had the rear tailgate on my not lifting up all the way and not closing at all..
Whilst I was changing both side lift struts (left side short, stubby 1400Nm version and longer right side) I noticed that the power pump's oil reservoir was empty..
Here's my method of topping up and bleeding the system.
Remove the pump from its foam housing and remove the crimped hose clip then turn the pump upside down so that the oil pot is uppermost. Carefully remove the pot by twisting it off its locating o-ring located on the pump housing and just add proper Mercedes hydraulic oil (if you have it) or, like I did, use ATF3 fluid, works fine. Disconnect the lift ram actuator off the tailgate's ball the get a spare 12v battery and connect two wires to the pump 12v feed terminals on the purple connectors, fill up the pump motor with oil (careful not to lose the small L piece breather that's located there)
Put back the oil pot and then cycle the pump back and forth a couple of times using the 12v battery. Do this 3 or 4 times then put the oil reservoir back and reinstall the pump horizontal within its housing, wait a few minutes then check the oil level on the side of the reservoir, there's normally a blue line marked half way up or a big + symbol, you need to get the level to match.
Whilst operating the ram, crack open both blue and red feed and return lines to get the air out (14mm head spanner) It took me a while as I'm working alone.
At the end it all worked fine, up, down, no slamming of the tailgate, no sticking spots, no more groaning motor.. And not a bloody Mercedes technician in site..
Hope it makes sense the way I've tried and explain it all, far from easy but not rocket science either..
Cheers!
Had the rear tailgate on my not lifting up all the way and not closing at all..
Whilst I was changing both side lift struts (left side short, stubby 1400Nm version and longer right side) I noticed that the power pump's oil reservoir was empty..
Here's my method of topping up and bleeding the system.
Remove the pump from its foam housing and remove the crimped hose clip then turn the pump upside down so that the oil pot is uppermost. Carefully remove the pot by twisting it off its locating o-ring located on the pump housing and just add proper Mercedes hydraulic oil (if you have it) or, like I did, use ATF3 fluid, works fine. Disconnect the lift ram actuator off the tailgate's ball the get a spare 12v battery and connect two wires to the pump 12v feed terminals on the purple connectors, fill up the pump motor with oil (careful not to lose the small L piece breather that's located there)
Put back the oil pot and then cycle the pump back and forth a couple of times using the 12v battery. Do this 3 or 4 times then put the oil reservoir back and reinstall the pump horizontal within its housing, wait a few minutes then check the oil level on the side of the reservoir, there's normally a blue line marked half way up or a big + symbol, you need to get the level to match.
Whilst operating the ram, crack open both blue and red feed and return lines to get the air out (14mm head spanner) It took me a while as I'm working alone.
At the end it all worked fine, up, down, no slamming of the tailgate, no sticking spots, no more groaning motor.. And not a bloody Mercedes technician in site..
Hope it makes sense the way I've tried and explain it all, far from easy but not rocket science either..
Cheers!
