Hydro Pneumatic Return Hoses
Return to Index

Understandings of Return-hoses

Functional Classification
Classified by the function, return-hoses are divided into the three groups as follows;
  1. Leak-back return
    Returns which came from oil-seals of cylinders & each oil-pleasure block. Even though the pressure is not so high, oil is leaking from Height-correctors continuously.

  2. Operational return
    Discharge returns, which came after the each action by Oil-pressure blocks. Such as the time of return oil through the height-correctors after adjust the position in low and direction change by power assists staring wheel.

  3. Ventilation
    It is a group as for letting out the pressure changes inside of cylinder and/or cylinder boots. The pressure changes are caused by suspension cylinder work - expansion and contraction.

Structural Classification
Classified by the assembly, return hoses are divided into three groups as follows;

  1. Octopus (familiar name: Knows as gathering return hoses)
    The assembled three group hoses as follows:

  2. Breaks valve return
    Leak-back return from break valve

  3. Operational return (High-pressure return)
    Operational return from front & rear height correctors, Control valve
    from Power-assist string and flow distributor.

  1. suction hose :the hose bails oil out toward high Pressure pump
  2. Operational return
  3. Breaks valve return
  4. Octopus: Group from Oil-pressure blocks
  5. Octopus: Front suspension cylinders
  6. Octopus: Air Ventilation

Octopus, Brake Valve return

Break valve return (c) and Octopus (D~F) run from Reservoir Tank toward
back from Engine-side,

Picture shows vehicle without Engine / Transmission. (At Auto Shop:

And goes along engine wall.(Left white arrow)
Below Height-corrector, you can see the Octopus body (describe later).
It connects the return-direction of Octopus body to leak-back of Right-Suspension cylinder.

Also Break-valve return runs under the Height corrector and go through
the vinyl-tube (center: white arrow)with hose from left-side of Octopus.

Tubes from left-side of sub-flame connect with Break-valve,
Priority-valve, Pressure-regulator and Left suspension-cylinder.


Operational-return(B) is ran toward engine front with suction hose.

Two hoses on Mark(white arrow) are came from both front & rear Height-correctors.

Divided two nearby flow distributor, connects each flow distributor, power-string-control valve.

For string line runs under the engine and transmission.

All of them are located in visible place, so you won't cause anxiety.

About Octopus

As describe before, Octopus consists:

White-line on the photo shows inside of the line.
It looks like three-line connection by rubber; it works connecting separately.
Red part is used 4mm, Blue-Green part is used 5mm plastic tubes and
connects each lines.。

The weakest part of Octopus is showed in X..
It turns over the upward and connects to Front Height-correctors ;thus,the part near the root easily crack and become continuousleaking. Difficult to repair, most annoying spot of leaking.

Front height-corrector has two Return-hoses.
Leak-back hose from Octopus group is shown photo(1).
Photo(2) with hose cramp is Operational-retrn. It seems cracking rarely for some unknown reason.

4-mm plastic tube comes to left-side of sub-flame, then being divided two between cramps by rubber-made T-joint (T) - one line runes to Priority valve (P) and another runs to Pressure regulator(R).

(C) is Leak-back from left Front suspension-cylinder and (B) is Brake valve return.

Priority valve

Located at left-back edge of front sub-flame.
Plastic tube of Above(P) connects rubber cap on the edge.

Brake valve return

Runs together with Octopus group to the left-edge of sub-flame and towards brake valve(red arrow).

In a case of exchange the Return-hose by official-dealer parts, it is easy to switch both Octopus and Brake valve return at the same time.
Hose exchange is simply take out and stick at the same point; however, both Height corrector and drive shaft prevent from working it.
Recommend to pull out right drive-shaft, if you are experienced.

(C) Y. Narabayashi

Translate: Taki Enomoto