Hydrolic reservoir

Cid

Member
Joined
Feb 17, 2022
Messages
23
Location
Arizona
I just bought a 1981 17 ft trailer. Top goes up and down nicely but I read about a hydrolic reservoir. Where can I find that little gem? Super novice here.
 
It's in the tongue battery box on newer trailers, I think it's there in yours as well. It is attached to the lifting motor and mine is white plastic. It will have a cap that's about 1.5" in diameter on the top that unscrews easily by hand. You check the fluid level with the top DOWN, which may make that difficult. I use a bent straw or piece of wire that I can insert as a dipstick. The fluid should be within about 1" of the top of the reservoir with the top down.

- Jack
 
Nope! My lift motor is under step. Thanks so much for the reply. I will keep looking.
 
I just looked in our HiLo brochure library and we don't have anything for 1981 HiLos. It appears there was a "SuperLight" 17' trailer made in 1980 and it had a manual lifting system with an option for motorized. In 1982, the smallest was 18'.

I still think the tank will be attached to the motor, so if you've found that, look there.

- Jack
 
Took a pic of motor. It says Super Jack 12 volt power jack. Maybe it is electric so there is no reservoir.?
 
Took a pic of motor. It says Super Jack 12 volt power jack. Maybe it is electric so there is no reservoir.?

Cindy, that may well be true. I have NO personal knowledge at all of earlier model HiLos. It could well be that the lift system is entirely driven by an electric motor without using any hydraulic assist at all. If so, that's one less thing you have to worry about.

Possibly, someone with a similar model year trailer will chime in and help confirm this.

- Jack
 
The 1981 owner's manual shows that there was an electric hydraulic lift system and an electric mechanical ball screw system depending on the model.

Since the motor is under the step, it sounds like it may be electric screw type system. Looks like a re-purposed electric tongue jack.

It also shows the integrated steel reservoir on the pump/motor in the hydraulic system.

https://www.hilotrailerforum.com/f49/1981-hilo-models-3467/

Edit: A quick google shows the Super Jack is an electric mechanical tongue jack.
 
Last edited:
Good find, Green River - thanks, bunches! I agree, if the motor is under the step, it's a modification of the tongue jack. Since my tongue jack can lift 3500# (and there are even higher capacity ones available), it makes me wonder why HiLo ever went with a hydraulic system. Seems an unnecessary complication, with more things to break down.

- Jack
 
Jack-Screw Lift System

My 1681-SLX HI-LO Funlte does indeed have an electric motor driven jack-screw. The HI-LO Care and Use Manual that was still in my unit when I bought it in 2017, shows the optional 12V Powerhead replacing the mechanical ball screw/hand crank lift system. The hand crank is under the front lounge/bed, by the 10gal fresh water tank & pump. The back page indicates the following HI-LO models: 2581, 2181, 1881, 1681-SL & 1681-SLX.
 
The motor and transverse jack-screw are just ahead of the axle behind the steps. The cables and pulleys are otherwise the same as the hydraulic lift.
 
Thanks so much. Is a copy of your owners manual on this site? Appreciate the information.
 
I would rather see one of those jacks on each corner of the upper half than the cables. I put 2x4s at each "resting point" when the top is raised and people are inside because, even though there is a catch to stop the cylinder creep, there's nothing there to stop the top from coming down if a couple of cables break or the bolts let loose.
 
Green River - the safety bar would keep the top from "crashing" down on occupants if the cables should break as long as it is engaged. An easy test you can do is to try to lower the top without pulling the safety bar release. When you push the switch to lower the top, it removes all lifting force on ALL the cables, which simulates a simultaneous failure of all the cables. The top will not come down. If you do this, don't leave the top resting on the bar, push the lift switch up to raise the top off the safety bar and put the support of the top back on the cables.

Edit: Another forum member, english775, just pointed out to me that what I've printed above may be totally wrong. He says the safety bar simply keeps the hydraulic ram from moving and that it in no way "supports" the top. If this is correct, then the bar WOULD NOT keep the top from coming down if all the cables broke. So, I'm going to have to do a bit of further research.

However, I'm still not convinced the top would "crash down" if a cable broke. It might if ALL cables broke simultaneously, but if they failed one at a time, the top would sag on the corner that was not supported and it would tend to bind in the tracks, which would stop it from lowering. Indeed, this has been the experience of members who have had cable failure. The top binds and it will not move until the low corner can be lifted to match the others.

In any case, there is no instance reported that I know of where the top has "fallen" dangerously due to cable failure.


I'm not saying using 2x4s to support the top when it is up is a bad idea. Several members do this if the top is going to be up for a long time to take the strain off the cables.

The problem with having a powered jack on each corner is that you need some way to regulate the lifting speed of them all so that the corners are lifted at the same rate. If one moves faster than the others, the top will "bind" as it goes up and lifting will stop.

- Jack
 
Last edited:
I would rather see one of those jacks on each corner of the upper half than the cables. I put 2x4s at each "resting point" when the top is raised and people are inside because, even though there is a catch to stop the cylinder creep, there's nothing there to stop the top from coming down if a couple of cables break or the bolts let loose.

That has been tried but with poor results. The motors all have to be synchronized at the same speed and apparently, that is very difficult to achieve.
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top