12v vs 115v hydraulic power units and hydraulic semi trailers

The wet line kit for the tractor is the proper way to do it of course and $2k isn't much in relation to the other costs related to the semi and trailer.

I have seen a Landoll hydraulic everything trailer that was powered by an onboard hydraulic unit run by a small diesel engine like a 3 cyl Kubota.

I would consider a small gas powered setup, basically just an 8hp gas engine coupled to a gear pump and a tank just like a log splitter setup. You wouldn't have any duty cycle issues, the trailer could be operated without the tractor if needed and it should cost perhaps $750 to put together.

The semi tractor cost me $2,300. I am reluctant to double its cost with a wet kit.

Yep, so have I.

My choice number 3 is almost what you are describing, except that there is a generator and an electric motor in the middle. Like I said, I already have a portable Honda generator, and since yesterday, have this single phase 1.5 HP hydraulic power unit.

Do the cylinders on your trailer use more than a gallon? You will need a valve, extra hoses, heavy duty battery cable to the trailer, and likely a larger reservoir, so this isn't as cheap as it seems.

Oh, OK. Scratch the reservoir.

I like #3 a lot, but what about a #4?

HF for the littlest Predator engine ($119), Burden Surplus for the pump and valving ($250, 2spl DA), and maybe a tank, if you don't weld up your own.

-- You never hear anyone say, 'Yeah, but it's a dry cold.' -- Charles A. Budreau

True. Keep in mind though, that most cylinders there are double ended, and those do not need a big reservoir.

Plus filters, belts, pulleys, mountings etc

In my experience, such projects end up very expensive and time consuming. Plus I do not trust HF engines, but I do trust Honda.

And all those surplus things at these surplus centers have some fatal flaws that make them somehow unusable for normal applications. (which is why they ended up at those surplus centers, cannot be sold through normal channels)

I am not trying to be difficult, just stating my past experience. Say, this hydraulic pump's description says "pump to operate hydraulic wheel motors on zero turn radius equipment applications including turf, light construction and other mobile equipment". What exactly it means, I am not sure, but it makes me slightly suspicious of whether this is a general purpose pump.

Direct mount the pump to the engine, no belts or pulleys needed.

Grok that. I saw that you already have the genset and power head, so make sure to document it. I'd like to see it when you're done.

I thought they were just NOS overages and misbuys by companies.

I haven't bought much from Burden, but everything I have has worked. No hyd, though.

-- You never hear anyone say, 'Yeah, but it's a dry cold.' -- Charles A. Budreau

Not TRUE. The surplus outfits buy the left-overs and oddball items that the companies just want to clear out of inventory. Plus items that were bought in large quantity then were not used.

Well for a cheaper way would be to hunt up a smallish wood splitter and swipe the engine and pump off it along with the small reservoir.

Personally I wouldn't want to put the extra hours on a good generator like that. I'd rather pickup the few parts to assemble the basic gas hydraulic power pack.

"Ignoramus25949" wrote in message

They may have an involute splined shaft that you can't find a pulley or coupler for, and have to make it like I did.

The replacement keyed shaft hydraulic pump I bought from Bailey's for $80 has been OK so far.

The 11 GPM log splitter pumps take a 5 HP gas engine.

You could monitor the 12V pump with an infrared thermometer and an ammeter while you made tests. I modified a battery charger into an adjustable 12V supply and used it to check out the HF 12V bilge pump yesterday. I bought the pump to water my lawn from the rain barrels. It doesn't seem to mind a high back pressure and flow restriction.

jsw

No belts or pulleys, direct coupled hydraulic pump. Mounting is just the four base holes on the engine. A return line filter is cheap. The trailer already has the valving, so all you need is a small tank and some hoses.

Those engines are pretty decent clones of the major brands and seem pretty reliable. Buy a second for the $120 and have it on hand for a quick change if needed. Changing it would be some 8 bolts and 10 minutes.

They aren't surplus, that is just the name of the company. at least 75% of the stuff they sell is new.

It will be a brand new Barnes two bolt mount two stage pump, not some surplus oddball.

The motor may look similar to a car starter, but is designed for hydraulic pump service. You'd certainly get in trouble using it for real continuous duty, but I'd think running it for several minutes would not cause overheating.

Does your semi have a 12 V electrical system? Over the road semis usually have a 24 V system, but intra-city semis can have a 12 V system.

I'd think having to haul an AC generator around would just make everything more complicated.

Jon

Something like this:

More than you want to pay, but it has a nice parts list showing you everything needed...

According to the specs I've found, standard duty cycle versions are

Would not work for me...

Way too expensive, I can have a real wet kit for this kind of money.