I have a 12v hydraulic power unit similar to this one:

http://goo.gl/UpLJG

The application (what I am trying to accomplish) is to operate this
hydraulic beavertail semi trailer:

http://igor.chudov.com/tmp/Trailking/Trailking-0009.jpg

When OI think about using this pump, I become concerned that it is
operated by a starter-type 12v motor and is desighed for pick-up truck
liftgates or snowplows, that is, very intermittent duty.

This beavertail trailer, while also essentialy intermittent, takes a
lot more work per unit of operation (pull beavertail lock, pull
extension lock, raise tail, extend extension, lower tail). That would
take this little motor a long time and it may overheat and burn out.

Is my concern justified?

I have a few options for powering this trailer. I am basing this on my
assumption that all cylinders are double acting, so not a lot of fluid
is needed.

The options a

1) Install a truck wet kit. cost: $2,000.

2) Use a 12v hydraulic pump that I already have. Cost: Small $$ for
wiring.

3) Use a 115v, self contained power unit that I purchased yesterday
along with a hydraulic H-press for $195. I would take along a Honda
generator that we have to run this pump. Cost: $195, minus whatever $$$
I can get for the press without the hydraulic pump,and the four way
manual valve.

This is a 1.5 HP unit with a continuous duty Marathon motor.

The plus of number 3, as I see it, is that the 115v hydraulic power
unit there, is not intermittent duty, and could do the job, with less
financial risk than plopping down $2,000 on a real wet kit. It would
be slower to work the tail cylinders than the wet kit, due to less
horsepower, but it is not a big deal. It will, however, cost me extra $5
every time the tail is operated, to pay extra hourly salary tot he
operator.