Dual Action Pump on Dump Trailer driving me nuts...

[Bonkers]

Hello all - to make this short and sweet I am having an issue with
my Southern Sales Dump Trailer. My hydraulics understanding can
be summed up as "I think that red liquid might be the fluid" so I
am hoping I missed something simple before shelling out $700+ for
a new pump. Im at my wits end and I NEED this trailer to work soon.

The pump is a Monarch M3551-0134 (see links below for specs.) Its
a dual action pump that worked flawlessly for years. It sat a project
for a few months, and when I went to dump it the battery drained out
and it was stuck in the air (had to drive it home that way.) Since then
it now raises very slow, and when I go to dump it the pump does not
activate - the bed then gravity falls which overflows the reservor. When
I hit the "up" button I can hear the actuator? click and the motor start
pumping, but when I hit the "down" button the other actuator clicks but
nothing else happens (except the inevitable mess...)

I read on here that it could be the battery so I replaced it with a yellow
top Optima - no change. I also read it could be the solenoid so I replaced
that - no change. A local businessman said he had the same issue and
discovered it was a bad ground so I spent all weekend grinding corrosion
off EVERY terminal with no change. The only other thing is that I had to
recently replace the Up/Down switch itself with an off-brand, but it worked
fine for a few weeks before this all started.

I'm hoping someone sees something I am missing. While I am willing to
pay the $700 for the new pump, I am not eager to give Monarch (SOSA)
more business considering theyve pretty much ignored my emails on this
issue. Its also a lot of money for me right now and I'd be hot if it turns
out to be a $5 widget on some sprocket I've completely overlooked. Can
anyone help me out here??

Thanks!

http://www.masondynamics.com/downloads/dl/file/id/33/monarch_dc_hydraulic_power_systems.pdf
http://internationalhydraulicsus.com/media/PowerPack_Dyna-Jack_M-3551.pdf

 

[woody]

to bad you don't live closer I would like to look at that. I would probably check the connections on your new switch you installed and if that checks out measure voltage at the solenoid. if possible post a couple of pictures of pump and connections.

 

[Harry in Ky]

I agree, the problem is most likely switch related. If the unit is power up and power down, the pump motor MUST be running in both directions. If it runs going up, but not when going down, the battery and solenoid can be pretty much eliminated since they obviously work. The issue is in the switches and/or wiring. You don't need a new pump.

 

[Xfaxman]

I don't understand why so many people replace good parts "hoping" to fix a problem.

Buy a digital multimeter and troubleshoot the problem, find the bad part. It's cheaper in the long run.

Multimeter Tutorial

 

[Bonkers]

Well I am really glad I didnt trust my multimeter because it was showing
the remote was good, the solenoid was good, and the actuators were both
good. All all my grounds were grounding... according to it I needed a new
pump...

But I did find the issue, thanks to you guys!

Apparently at some point (long before I came along) there was an issue
with the previous remote. The previous owner installed a new one and
(im guessing) accidently mixed up some wires. Instead of fixing the
remote he just re-wired the lead from the pump. So when the old setup
failed for me, I simply wired the new remote to the (seemingly) correct
wires... which now lead to the wrong terminals on the pump.

So short explination: the green wire in the remote lead to the black wire on
the lead, which was then connected to the wrong terminal on the solenoid.
The only wire that was correct was the lift which is why it would go up and
not come back down.

After about two hours of cussing the downpouring rain I discovered where
the wires were crossed up. Now the wrong wires are going to the correct
locations on the pump and everything is right with the world again. When the
weather dries up some I will go out and rewire the solenoid and pump so that
it has the correct setup.

Again guys - thanks for the help!

How to Wire a Dump Trailer Remote - International Hydraulics Blog