Autostacker™ Parking Lift 26 P/N 5900248 — Rev. B — May 2021
Working with Return Lines and Compression Fittings
Autostacker uses Return Lines made of a roll of ¼ inch, polyethylene Tubing (also called Poly-Flo®)
that is used with Compression Fittings to attach to the Air Cylinders and the Return Line Connectors.
The components involved with Compression Fittings include:
• ¼ inch, black, polyethylene Tubing. The Return Lines require several lengths of tubing to
make the necessary connections back to the Console.
• Elbow Compression Fittings (also called a 90° fitting). The Return Lines use Elbow Fittings to
attach to each Hydraulic Cylinder and one that connects to the Console.
• Tee Compression Fitting. The two Return Lines hooked up to the Hydraulic Cylinders connect
to a Tee Compression Fitting that goes back to the Power Unit.
• Nuts, Ferrules, Rods, and Threads. Each connector on Elbow and Tee Compression
Fittings have a Nut, Ferrule, Rod, and Threads. The Nut holds the tubing and Fitting together. The
Ferrule compresses when you tighten the Nut on the Threads to make a secure connection. The
Rod goes inside the Tubing so that there are no leaks.
The following drawing shows the components of a connector on a Tee Compression Fitting
Important:
Ferrules can only be tightened once
. When you tighten the Nuts on the
Threads, the Ferrules get compressed; it changes shapes and
cannot
be used
again.
Connect the Return Line
The Return Line takes extra Hydraulic Fluid from the Hydraulic Cylinders and returns it to the Power
Unit’s Hydraulic Fluid Reservoir; it also allows air to move in and out of the Hydraulic Cylinders.
One end of the Return Line connects to the Power Unit (where it goes into the Reservoir). There are
two other ends; they attach to Return Line Connectors, which are near the top of each Hydraulic
Cylinder.
The Return Line comes as one long roll of tubing; you need to cut it into sections of the right length.
If you have a Multi-Lift setup, this procedure will be slightly different for you
; see
Multi-Autostacker for modified instructions.