SECTION 13-D 1956 BUICK CONVERTIBLE TOP POWER SYSTEM

13-12 OPERATION OF 1956 BUICK FOLDING TOP

When the control knob is pushed forward, the feed wire is connected to the red motor lead and the motor and pump assembly operate to force the hydraulic fluid through the hoses to the lower ends of the double-acting cylinders. The fluid forces the piston rods out of the cylinders, thus raising the top. The fluid in the top of the cylinders returns to the pump for recirculation to the bottom of the cylinders. When the control knob is pulled rearward, the feed wire is connected to the dark green motor lead and the motor and pump assembly operate in a reversed direction to force the hydraulic fluid through the hoses to the top of the cylinders. The fluid forces the piston rods into the cylinders, thus lowering the top. The fluid in the bottom of the cylinders returns to the pump for recirculation to the top of the cylinders.

 

13-13 CHECKING PROCEDURES

Mechanical Checking Procedure

If there is a failure in the 1956 Buick Hydro-Lectric system and the cause is not evident, the mechanical operation of the top should first be checked. If the folding top assembly appears to have a binding action, disconnect the lift cylinder piston rods from the top linkage and then manually lower and raise the top. The top should travel through its down and up cycle without any evidence of a binding action. If a binding action is noted when the top is being locked at the header, check the alignment of the door windows, ventilators, and rear quarter windows with relation to the side roof rail weatherstrips. Make all necessary adjustments for correct top alignment. If the top does not operate hydraulically after all mechanical problems have been corrected, the Hydro-Lectric system should then be checked for electrical or hydraulic failure.

Checking Operation of 1956 Buick Convertible Top Lift Cylinder

  1. Remove the rear seat cushion and folding top compartment side panel assembly.
  2. Operate the folding top control switch and observe the lift cylinders during the “up” and “down” cycles for these conditions:
    • If the movement of the cylinder rods is not coordinated or sluggish when the motor is actuated, check the hydraulic hoses from the motor and pump to the cylinders for kinks.
    • If one cylinder rod moves slower than the other, the cylinder with the slow moving rod is defective and should be replaced.
    • If both cylinder rods move slowly, or do not move at all, check the pressure of the pump. See subparagraph d below.

Checking Fluid Level in Reservoir

  1. Operate top to raised position.
  2. Remove motor and pump shield from rear compartment.
  3. With a straight-bladed screw driver remove filler plug indicated at “C” in figure 13-17.
    1956 Buick Pump and Motor Connections

    1956 Buick Pump and Motor Connections

  4. Insert dip stick into reservoir. Fluid level should be two (2) inches from top of reservoir. If fluid is low, add hydraulic fluid Delco #11 (G. M. Hydraulic Brake Fluid Super #11).
  5. Reinstall filler plug and pump and motor shield.

Checking Pump Pressure

  1. Remove the motor and pump assembly from the rear compartment as described in par. 13-14 (a).
  2. Install plug in one port and pressure gauge in port to be checked as indicated in figure 13-18.