Improve Roll-Off Performance

Everyone knows that repairs or replacements must be made when something fails, wears out and no longer works. These repairs and replacements are most times costly, not only the replacement price, but downtime and potential break in time.

Often the new replacement parts have the same fitting tolerances as if they were new, which increases the stresses and strains forced on them as they try to break themselves in with other parts already worn and broken in.

These conditions increase the need to pay more attention and increase inspections both on the new replacements, but maybe more important their effect on other parts or equipment.

An example could be installing a new cable on a roll-off hoist and not noticing the cable sheave had a worn bushing and cable groves in the sheave made by the older cable. The result could require more greasing of the sheave until the new cable wears itself into the sheave (break in period).

When checking or inspecting a roll-off hoist, listen as well as look because any rubbing, scraping, squeaking or friction noise is a sign of excess wearing and therefore a forecast of a failure to happen.

Remember to always use a good grade of grease.

More information can be found in GalFab’s Roll-off Hoist operating manual entitled “Lubricating Information for Roll-off Hoists” 12.28.10.

Pressure Build Up In Hydraulic Oil Reservoirs On Roll Offs

Pressure build up is caused when the air filter located on top of the Hydraulic reservoir becomes clogged, and stops the oil reservoir from breathing (allow air in and out).

This is a special 10 micron air filter for Hydraulic systems; its purpose is to keep dirt and other contaminants out of the Hydraulic oil.

The air filter will become clogged through everyday working conditions and should be replaced a minimum of every six months. Should the working conditions be extremely dirty, then it should be changed more often (every 3 or 4 months).

A regular oil filter that looks the same will not work and will cause oil leaks and gasket failures; you must use a special filter for air.

A clogged air filter may be checked by removing it and blowing in and sucking out through the center hole of the filter. If the air isn’t easily moved through the filter so that you can feel or hear it then the air filter is becoming clogged and needs replaced.

Oil residue coming from the oil reservoir will help clog the air filter and must be watched. Should this happen, the air filter should be replaced.

Before adding oil to the reservoir all the hydraulic cylinders should be retracted (i.e. lift cylinders down and winch cylinders retracted) with no oil showing in the sight gauge.

The oil in the sight gauge should be clear, not milky or air bubbly, and only filled to the center of the sight gauge leaving 4 to 5” of expansion room at the top of the reservoir.

Over filling with hydraulic oil, leaving the P.T.O. engaged, letting gravity lower the lift cylinders, or letting a container unload by gravity can cause the oil to entrap air and expand which will help clog the air filter and when this happens the air filter must be replaced.

New Roll off hoist users, inexperienced drivers, and untrained service personnel must be informed and cautioned to check and replace the air filter before it clogs causing pressure build up in the oil reservoir which will blow seals and gaskets and cause other leaks.

GALFAB’s air filter is Part No PH 12. We recommend using original equipment.

Galfab, Inc. Roll-off Hoist Model Numbering Systems

Galfab, Inc. has a smart numbering system to establish their Roll-off hoist Models

  1. Style – 1st and 2nd letters =
    • **DL – Dead Lift
    • **EH – Extendable Tail Heil (Dead Lift)
    • **EX – Extendable Tail to the ground
    • **HH – Heil Huge Haul (Dead Lift)
    • **IO – Inside-Outside Rail
    • **MM – Mil Mar (Dead Lift)
    • **OR – Outside Rail Tail to the Ground
    • **OX – Outside rail Short Extendable Tail to the Ground
    • **SI – Inside-Outside for (Dempster and Dead Lift Containers)
    • *ORHH – Outside Rail for HH (Dead lift containers) Frame O.D. = 35” and cable has swivel eye.
    • *ORSB – Outside rail – Slide Back (also known as Fast Back)

    ** The letter “N” in front of these (making three letters) denotes 10” sub-less frame

  2. Capacity – 3rd and 4th Number denotes rated capacity of lifting cylinders. (*except ORHH and ORSB)
    • 50 = 50,000#
    • 60 = 60,000#
    • 75 = 75,000#
    • Etc.
  3. The 5th, 6th, and 7th numbers are the cab to center of tandem axle required minimum length
    • 174 = 174” C.A.
    • 194 = 194” C.A.
    • 228 = 228” C.A.
  4. The 8th letter denotes the type of lift cylinders
    • S = Single Stage Double acting
    • T = Telescopic multi stage Double acting
  5. The next three plus numbers are the stroke of the lift cylinders
    • 072 = 72”
    • 118 = 118”
    • 074.5 = 74.5”


Hydraulic Lift Cylinder Clearance When Installing Roll-Off Hoist

Recently we have learned of a pair of lift cylinders being destroyed because of mounting bracket interference when the Roll-off Hoist was raised.

Precautions must be taken to assure clearances for fenders, tarper mounting brackets, bumpers, etc. before and after they are installed.  The hoist must be raised to its full dumping height either with its hydraulics or an overhead lifting crane to establish the amount of needed clearance.  See drawing below.