The Stovebolt Site Forums The Parking Lot Big Bolts Filling hydraulic hoist reservoir correctly on 2tn

I got a 1957 2ton Truck with a St Paul Model AH160 Box hoist. The seal leaks abit and I need to top off the reservoir . My question is how do I do this correctly? Do I rasie the hoist all the way and fill it or do I leave it down and fill it? Do I need to bleed it? If so how do I? The hoist does go up about 75% of the way right now. HELP ME PLEASE!

thanks!

If cylinder is fully extended and you fill reservoir then where does oil from cylinder go?

Think I would fill and extend until I know cylinder has no air and you have a little excess in tank.

Dan Bentler

Dunno that model, but if it is the big single cylender with the fill fitting on the top end you fill it with the hoist down. Filling while up will result in overflow when you lower the hoist and if the cap is installed and doesn't have a vent to release the excess fluid you may blow some seals.
Using a hand pump that screws onto a gallon jug works great for filling, there's plenty of room to work under there, just requires some reaching.

If it has a seperate resivoir you'll also want to fill it while the hoist is down. Like Dan said, if the box is up and you top off the fluid, there will be a HUGE mess when you lower the box.

yeah it;s a single cylinder type with fill cap on top, thanks for your help! i will fill it box down.

I have used a suction gun to fill mine. Sometimes, they're hard to get at when the bed is down. If you do end up having to raise it, you'll need to leave the cap off the first time you let it down, so any excess fluid can escape.

And above all, BE SAFE!!! Do NOT go under a raised bed unless it is blocked up securely!

If there is a reservoir ( and it has a breather cap) and it's a piston cylinder then any air in it will work itself out after a few cycles. A lot of the underbody hoists had a little air bleeder screw in the top where you fill them. If it does not don't worry about it but if no reservoir then just fill to near full and run it up and down a few times. you can use a pipe plug and drill an 1/8" hole in it and put small cotter key in it to keep dirt out but it will allow for expansion of the oil.

I agree with filling it with the bed down, and have no problem with that idea except ONE.

With the fill point under the bed, it's a hect of a job getting the fluid into the reservoir.

I think some more-off designed my truck hoist.

Dan

What is the PSI of the pump. I'm assuming its a gear type. Low pressure/high volume? I see there are two plugs opposite of the pump. Could you put hydraulic remotes on there to operate other hydraulic components/machinery?

This must be the week for resurrection of old threads. Eight years on this one. Most of these guys are long gone. Perhaps our more active members can help you out.🛠