Originally Posted by javelin
I am not a jack expert at all and at the risk of being insulting (especially because you said you know the manual override process):
- set your parking brake for safety (if you do get the jacks down)
- visually check all jacks and ground to see if there are any obvious hydraulic leaks anywhere
- jack fluid near full in the pump reservoir?
- adjust the appropriate valve body screw fully clockwise for the jack you want to bring down
- run drill clockwise to extend; counter clockwise to retract the specific jack
If nothing is happening then I defer to someone who has actually been into the pump body and knows how the motor and pump are coupled, or if there is some other internal pressure valve that may not be allowing pump pressure to build up as the motor turns. Another call to Thor might help clarify?
Not insulting, but I believe some of your logic is incorrect, as I believed the same at one time.
Talking about a Lippert system here.
The pump, & its motor, run in a counter-clockwise rotation when viewing it from the end facing outward of the RV.
The solenoid bypass screw, you mention, is to open flow to its designated jacking cylinder, each valve is basically an open or closed type of valve.
There is also a directional valve that comes into play.
Its default is for direction of flow to retract (raise) the jacks.
To manually extend the jacks may be somewhat complicated, especially for someone not sure what to do, as the directional valve will need 12vdc power to activate its valve direction change.
The solenoid valve to the specific jack to be deployed opened.
Then the spinning of the motor with a drill in left hand direction.
I don't think Lippert tells you this, nor recommends, trying to level with their system manually.
The pump is a gear pump, directly driven, by the motor inline, using 12vdc power.
It will take a lot of trash going through the pump to ruin it.
If the reservoir fluid is clean, then no worries there.
I could not find a replaceable pump without purchasing an entire pumping unit at about $1800 or something.
With a volt meter, test the connections at the motor to determine power is present.
Hold ground probe to the frame, positive probe test connections to see power is present.
One of the 12vdc 50 or 100 amp breaker powers this motor, check for flags popped out, or physically use the volt meter to verify power passing through.
Make sure "use" switch is on & parking brake engaged.
The parking brake provides the Ground connection to allow system to work, ignition key in on position provides the positive power needed.
You should be able to jumper power on the motor to get it to spin.
Running the motor in clockwise will not do anything.
It is the valve combination that allows flow to be directed for functions directed.
The solenoid valves are aka logic valves.
This is from my experience from problems we have had.
Trying to level the RV, have someone near the hydraulics unit, to listen for the motor to run when a prompt is made for leveling, or returning the jacks up from the control panel.
That will tell you the motor/pump is working.
Our problem is they would not return when prompted to and needed to be done manually.
It ended up being a bad directional valve.
Another time was nothing worked at all.
An error message was displayed, all power/fuse/breaker tested good, but nothing could be made to work.
That was a main "brain" component needing replaced.
It was located inside the roof of an outside basement compartment.