Hydraulic lift uneven, is this normal?

Mightychan

Member
Oct 8, 2016
157
Panama City FL
Boat Info
2005 DA 420, AB Dink
Engines
Cummins 6CTA
Hi all, the lift on my new to me DA420 seems a little out of whack. When extended, the starboard side sits a little lower than port, and when it retracts the port side comes up sooner and leaves an uneven gap between the swim platform and the lift platform. The lift platform will be closer to the swim platform on the port side than starboard. I can lower a tad and re-lift, and it gets better, but never ends up perfectly even. Is there a way to adjust the lift, or is this just normal behavior? Thanks!
 
That's not normal. I have the same year 460DA and it has a GHS lift. If your lift is the same manufacturer give them a call with your symptoms. Could be as easy as needing to bleed the lines.
 
Only if both motors are wired together . Raise hatch, disconnect the high side motor, raise low side to match, reconnect motor
 
If it's a GHS lift there is only one motor and pump. There are two hydraulic cylinders.
 
Most of the swim platform lifts use a metering block after the pump to balance the pressure between the actuators. The metering block allows shared pressure to be shifted when one ram reaches its stop. If one ram has air in the line....it will lag the other ram when raising the platform. Bleeding resolves 90% of this issue.

If it persists after bleeding I would tee a high pressure hydraulic gauge on each of the lift lines to see if the pressure is out of whack between the actuators. If the pressure is consistent.....then the slower ram may need a new seal kit. After 13 years on salt water it may be a good idea to have the rams rebuilt on the next haul out.
 
I have a GHS lift on my boat and had the same issue. I called GHS and purchased a hose that allowed me to bleed the cylinders. I got in the water to do this and it was a real pita. Totally random and took several quarts of hydraulic fluid. If you can get your boat on the hard it would be much easier. Good luck.
 
How many of you guys run your lifts all the way down when launching and retrieving? I only lower as much as needed and get some jerkiness at the top. Wondering if this is causing air to get into the system? I think the manual says to run all the way up and down a few times to purge.
 
How many of you guys run your lifts all the way down when launching and retrieving? I only lower as much as needed and get some jerkiness at the top. Wondering if this is causing air to get into the system? I think the manual says to run all the way up and down a few times to purge.
GHS lift on my boat. When I launch or retrieve the dink, I cycle it all the way up and down.
 
it’s a good idea to fully cycle the lift when you use it. The jury is out on whether or not it will force air out of the system. If you think about it....the actuator piston has a pressure port above and another below it....one to expand and the other to retract.

If air is in the actuator, forcing fluid compresses the air into the actuator resulting in a lag before the platform moves. Reverse the actuator and the air mixed with the fluid flows into lines that connect it to the pump. Depending on the length of the line...the air infused fluid may never find its way back to the pump reservoir resulting in one actuator seemingly lagging the other. Similar to having air in a automotive brake line.

There is a way to bleed most lifts in the water either at the pump/manifold or actuator but I would rather do it at a haul out or short haul.
 
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All of the responses are assuming an issue with the pump or hydraulics. There are adjustments that can be made to the lift when the boat is on the hard that can even it out if it's not level. We're having the same issue but I'm just going to wait until the end of the season to deal with it. The swim platform is only off by about 1" or so at the moment and it's not worth the $$$ to haul out the boat just to deal with the swim platform.
 

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