1957 Buick Convertible Top

1957 Buick Front Roof Rail Corner Brace

Repeat on opposite side if necessary. NOTE: This adjustment is limited. If additional adjustment is required, it can be made at the folding top male hinge.

Adjustment of 1957 Buick Convertible Top at Lock Handle Striker and Front Roof Rail Guides

If a difficult locking action, caused by misalignment of the front roof rail lock handle strikers is encountered at the front roof rail, or if a closer fit of the front roof rail to the windshield header is desired, proceed as follows:

1. Unlatch top and raise it above windshield header.
2. Loosen striker attaching screws and adjust striker up or down or from side to side as required. If necessary, also loosen front roof rail guide attaching screws and adjust guide as required.
3. If an additional upward adjustment of the front roof rail is desired, remove handle and install emergency washer into lock spindle cavity in handle, then install handle with emergency attaching screw.

Adjustment of Rear Quarter Trim Stick and Support Assembly

In some cases, the rear quarter trim stick and support assembly may be adjusted slightly to remove wrinkles of the top material at the rear quarter area. To adjust the trim stick and support proceed as follows:

1. Remove screws securing 1957 Buick Convertible top compartment bag to seat back panel.
2. Loosen support attaching bolts and outer guide attaching screws and adjust trim stick as required to obtain proper fit of 1957 Buick Convertible top material; then tighten support attaching bolts.
3. Lock front roof rail to windshield header; then position trim stick outer guide to contact top of inner guide and tighten outer guide attaching screws.
4. Install compartment bag attaching screws.

Adjustment of Top at Control Link Adjusting Plate (Series 40-60)

1. If there is a sag in the joint between the front and center side roof rail, proceed as follows:
   • Remove folding top compartment side trim panel and loosen front bolt securing control link adjusting plate indicated in figure 13-102.

1957 Buick Convertible Top Adjustments-Series 40-60

Loosen rear bolt securing control link adjusting plate; then pivot rear portion of adjusting plate over serrations as required to obtain desired stack height; then tighten bolt.

Adjustment of Top at Control Link Adjusting Plate (Series 50-70)

1. If there is a sag in the joint between front and center side roof rail, proceed as follows:

• Remove folding top compartment side trim panel and loosen two (2) bolts securing control link adjusting plate indicated in figure 13-103 sufficiently to permit adjustment of the plate.

1957 Buick Folding Top Adjustments-Series 50-70

2. If the top linkage does not stack properly, proceed as follows:
   • Loosen bolts securing control link adjusting plate sufficiently to permit adjustment of the plate.
   • Without any change in the “up” or “down” location of the adjusting plate, move adjusting plate forward or rearward (horizontally) over serrations as required to obtain desired stack height. Then tighten bolts.

Adjustment of 1957 Buick Convertible Top at Male Hinge Support (Series 40-60)

The male hinge is entirely new in design and method of attachment, thereby requiring new service procedures. The male hinge is secured to the support by three bolts at the front of the support and by three bolts at the side of the support. Prior to making an adjustment to raise the top linkage at the male hinge, loosen the two bolts securing the folding top rear quarter trim stick front outer guide to the rear quarter panel. This will prevent any possible damage to the top when it is raised after adjustment. After making an adjustment at the male hinge, check the folding top at the rear quarter area for proper fit and where necessary adjust the guide and the trim stick and support assembly.

1. If there is an excessive opening between the side roof rail rear weatherstrip and the rear quarter window, or if the front roof rail is too far forward or rearward, proceed as follows:
   • Loosen three male hinge attaching bolts. “A” figure 13-103.
   • Move hinge fore or aft, as required, then tighten bolts.
   • Lock front roof rail to windshield header, and check side roof rail alignment and readjust if necessary.
   • Lock front roof rail to windshield header and check fit of 1957 Buick Convertible top material at rear quarter trim stick area and, if necessary, adjust trim stick. See “Adjustments of Rear Quarter Trim Stick and Support Assembly”. If adjustment is not necessary, tighten outer guide attaching screws.
2. If the side roof rail is too high or too low at the rear quarter window area, proceed as follows:
   • Loosen bolts securing rear quarter trim stick front outer guide.
   • Loosen attaching bolts “B” figure 13-103. In addition to bolts, support is secured firmly in place by serrations on contacting surfaces of support and brace.
   • Adjust support up or down as required, then tighten bolts.
   • Lock front roof rail to windshield header, and check side roof rail alignment. Readjust if necessary.
   • Check fit of top material at rear quarter trim stick area and, if necessary, adjust trim stick front guide. See “Adjustment of Rear Quarter Trim Stick and Support Assembly”.

Adjustment of 1957 Buick Convertible Top at Male Hinge Support (Series 50-70)

The adjustments at the male hinge support are similar to those on previous styles. Prior to making an adjustment to raise the top linkage at the male hinge, loosen the two bolts securing the folding top rear quarter trim front outer guide to the rear quarter panel. This will prevent any possible damage to the top when it is raised after adjustment. After making an adjustment at the male hinge, check the folding top at the rear quarter area for proper fit and where necessary adjust the guide and the trim stick and support assembly.

1. If there is an excessive opening between the side roof rail rear weatherstrip and the rear quarter window, or if the front roof rail is too far forward or rearward, proceed as follows:
   • Loosen four male hinge attaching bolts. “A”. See figure 13-103.
   • Move hinge fore or aft, as required, then tighten bolts.
   • Lock front roof rail to windshield header and check side roof rail alignment, and readjust, if necessary.
   • Lock front roof rail to windshield header and check fit of top material at rear quarter trim stick area and if necessary, adjust trim stick. See “Adjustments of Rear Quarter Trim Stick and Support Assembly”. If adjustment is not necessary, tighten outer guide attaching screws.
2. If the side roof rail is too high or too low at the rear quarter window area, proceed as follows:
   • Loosen bolts securing rear quarter trim stick front outer guide.
   • Loosen attaching bolts “B”. In addition to bolts, support is secured firmly in place by serrations on contacting surfaces of support and brace.
   • Adjust support up or down as required, then tighten bolts.
   • Lock front roof rail to windshield header and check side roof rail alignment and readjust if necessary.
   • Check fit of top material at rear quarter trim stick area and, if necessary, adjust trim stick front guide. See “Adjustment of Rear Quarter Trim Stick and Support Assembly”. If adjustment is not necessary, tighten outer guide attaching screws.

13-20 1957 BUICK CONVERTIBLE TOP TRIM ASSEMBLY (ALL SERIES CONVERTIBLES)

The 1957 Buick Convertible top trim on the 1957 convertibles is attached in a manner similar to that used on past models except for the “floating” trim stick at each rear quarter. Due to the new trim stick design, the removal and installation procedure of the top trim in the quarter area is slightly different from the procedure used on past models.

Removal of 1957 Buick Convertible Top Trim Assembly

1. Place protective covers on all exposed panels which may be contacted during procedure.
2. Remove following trim and hardware items:
   1. Rear seat cushion and back.
   2. Folding top compartment side trim (arm rests).
   3. Side roof rail wear weatherstrip; then loosen top flaps from rail.
3. At the front of body, raise front roof rail, remove retainers and front weatherstrip and detach top material from front roof rail.

1957 Buick Folding Top Components at Rear Window Area

Installation of 1957 Buick Convertible Top Trim Assembly

1. Position rear bow for proper installation by installing spacer sticks as shown in figure 13-107.

1957 Buick Rear Bow Positioning

Note that sticks are placed 30 inches apart, each being 15 inches from the centerline of body. The stick length “X” is approximately 18 1/2 inches for Buick “40” and “60” Series Convertibles or 21 inches for Buick “50” and “70” Series Convertibles, measured from chrome belt molding to rear rolled edge on tacking strip.

1957 Buick Tacking Rear Quarter Stay Pads

Note that inner edges of pads are 26 1/4, inches from center of trim stick. Lower edges of pads are set flush with lower edge of trim stick for positive location.

1957 Buick Back Curtain Assembly

The shorter lower edge of curtain should be set flush with lower edge of trim stick as shown in figure 13-109. Tack curtain to a point opposite outer edges of window and leave outer ends of curtain loose. Tacks should be placed close to each side of every screw hole in trim stick. Then pierce back curtain for each screw.

1957 Buick Trim Stick Fillers

Recement if necessary.

1957 Buick Pad and Curtain Attachment to Large Bow

Trim off excess material at rear bow.

1957 Buick Tacking Convertible Back Curtain

Make sure all fullness has been drawn from curtain before trimming off excess at rear bow.
NOTE: It may be necessary to install additional trim stick screws to check the fit of the curtain along belt line.

1957 Buick Convertible Top Sealing

Note that sealer is applied at two locations along each seam as indicated by two arrows.

1957 Buick Sealing at Rear Bow

Trim off excess material. NOTE: The tacks outboard of seams should be restricted to a distance not to exceed six inches, which is the length wire on binding extends past seam.
IMPORTANT: This tacked joint must be sealed with an approved convertible top fabric sealer. Sealer should be applied from outside, as indicated at “A”, and from underside, as indicated at “B”. Sealer should be applied so that it will flow around tacks for proper seal.

1957 Buick Top Attachment at Rear Trim Stick

Use marked line as locating reference.
IMPORTANT: Apply a waterproof sealing tape over tacked edges of back curtain and top material so that after back curtain and top material are trimmed, tape can be wrapped around to cover inside of trim stick. The inset in figure 13-120 shows final installation of seal ring tape after top installation has been checked and top material trimmed.

Removal and Installation of External Top Only

To install the external top material only, remove the material without disturbing the back curtain or stay pads. Then reinstall the replacement top trim as outlined in the installation of the entire top starting with step 10.

Removal and Installation of Back Curtain Only

To install a replacement back curtain, it is necessary to detach the top material from the rear belt trim stick and from the rear bow. By making reference marks on the folding top trim and on the sealing tape along the belt molding, the top material can be returned to its original position with a minimum of refitting.

13-21 1957 BUICK HYDRO-LECTRIC SYSTEM (ALL SERIES CONVERTIBLES)

The 1957 Buick Convertible top Hydro-Lectric System is the same as used on past convertibles except for the installation of the motor and pump assembly. On past convertibles, the motor and pump unit was installed in a vertical position behind the left side of the rear seat back. On 1957 convertibles, the unit is installed in a horizontal position behind the center of the rear seat back.

Figure 13-121 shows an exploded view of the motor and pump assembly. The parts are indicated by letters.

1957 Buick Disassembling Motor and Pump Assembly

Removal of Motor and Pump Assembly

1. Operate 1957 Buick Convertible top to full “up” position.
2. Disconnect positive battery cable.
3. Place protective covering over rear seat back and cushion.
4. Working inside body, detach front edge of folding top compartment bag from rear seat back panel.
5. Working on inside of body over the rear seat back, remove pump and motor shield attaching screws and remove shield.
6. Remove clips securing the wire harness.
7. Disconnect motor leads from the wire harness, and remove clips securing hydraulic hose to rear seat back panel.
8. To facilitate removal apply a rubber lubricant to pump attaching grommets; then carefully disengage grommets from floor pan. See figure 13-122.

1957 Buick Motor and Pump Assembly Attachment

NOTE: Venting reservoir is necessary in this “sealed-in” unit to equalize the air pressure in reservoir to that of atmosphere. This operation prevents possibility of hydraulic fluid being forced under pressure from disconnected lines and causing damage to trim or body finish.

1. Disconnect hydraulic lines from sides of motor and pump assembly, and cap open fittings to prevent leakage of fluid. Use a cloth to absorb any leaking fluid, then remove unit from rear compartment.

Installation of Motor and Pump Assembly

1. If a replacement unit is being installed, fill reservoir unit with specified Delco #11 hydraulic fluid (G. M. Hydraulic Brake Fluid Super #11). See “Checking Fluid in Reservoir” for proper fluid level.
2. Connect hydraulic hoses, engage attaching grommets in panel and connect wiring.
3. Remove reservoir filler plug and place absorbent rags under filler opening.
4. Connect battery and operate top through its up and down cycle with filler plug removed from reservoir.
5. Check connections for leaks and check fluid level in reservoir. See “Checking Fluid in Reservoir” for proper level.
6. Install previously removed parts.

Disassembly of Reservoir Tube from Motor and Pump Assembly

1. Remove motor and pump assembly from body.
2. SCRIBE A LINE across the pump end plate, reservoir tube and reservoir tube end plate as shown in figure 13-123 to insure correct assembly of parts.

1957 Buick Motor and Pump Assembly

Assembly of Reservoir Tube to Motor and Pump Assembly

1. Position sealing ring on pump and assemble reservoir tube to pump according to scribe marks.

NOTE: Bracket assembly on tube should be located at outer end when tube is assembled to pump.

1. Position sealing ring on tube end plate and place end plate on reservoir tube, lining up the scribe marks. Install and tighten attaching bolt.
2. Place unit in horizontal position and fill with fluid until level of fluid is even with bottom of filler plug hole.
3. Make sure that sealing ring is on the filler plug, before installing filler plug.

Operation of the 1957 Buick Convertible Top

The principles of 1957 Buick Convertible top operation are the same as on previous models. When the control switch knob is pushed forward, the battery 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 in the cylinders upward, 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 switch 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 in the cylinders downward, thus lowering the top. The fluid in the bottom of the cylinders returns to the pump for recirculation to the top of the cylinders.

Operation of Pump Assembly

The rotor type pump assembly is designed to deliver a maximum pressure in the range of

240 psi to 280 psi. The operation of the pump assembly when raising the top is as follows:

1. Raising the 1957 Buick Convertible Top. When the red motor lead is energized, the motor drive shaft turns the rotors clockwise as indicated by the large arrow in figure 13-124.

1957 Buick Raising Convertible Top

The action of the pump rotors forces the fluid under pressure to the bottom of each cylinder forcing the piston upward. This action causes the fluid above the piston in each cylinder to be forced into the pump, which recirculates the fluid to the bottom of the cylinders. The additional fluid required to fill the cylinder due to piston rod displacement is drawn from the reservoir as indicated.

1957 Buick Lowering Convertible Top

The action of the pump rotors forces the fluid under pressure to the top of each cylinder. This action causes the fluid below the piston in each cylinder to be forced into the pump which recirculates the fluid to the top of each cylinder. The surplus hydraulic fluid due to piston rod displacement flows into the reservoir as shown.

Mechanical Checking Procedure

If there is a failure in the 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 top lift cylinder piston rods from the top linkage and then manually raise and lower the top. The top should travel through its up and down 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 a failure continues to exist after a check for mechanical failure has been completed the Hydro-Lectric system should then be checked for electrical or hydraulic failures.

Electrical Checking Procedure

If a failure in the Hydro-Lectric system continues to exist after the mechanical operation has been checked the electrical system should then be checked. A failure in the electrical system may be caused by a low battery, breaks in the wiring, faulty connections, mechanical failure of an electrical componeJ1t, or wires or components shorting to one another or to the body metal. Before beginning checking procedure, check battery according to procedure recommended in Buick Chassis Service Manual.

1. Checking for Current at the Folding Top Control Switch
   • Disengage terminal block from rear of switch.
   • Connect light tester to central terminal of switch terminal block.
   • Ground light tester ground lead to the body metal.
   • If light tester does not light there is an open or short circuit between battery and switch.
2. Checking the Folding Top Control Switch.

If there is current at the feed wire terminal of the terminal block the operation of the switch can be checked as follows:

• Place a #12 jumper wire on switch terminal block between center terminal (feed) and one of two motor wire terminals. If motor operates with jumper wire but did not operate with switch, the switch is defective.
• Connect jumper wire between center terminal (feed) and other motor wire terminal on switch terminal block. If motor operates with jumper wire, but did not operate with switch, the switch is defective.

1957 Buick Checking Switch Terminal Block

4. Checking Switch to Motor Lead Wires

If switch is found to be operating properly, the switch to motor lead wires can be checked as follows:

• Disconnect green switch-to-motor wire from motor lead in rear compartment.
• Connect a light tester to green switch­to-motor wire terminal.
• Ground light tester ground lead to body metal.
• Pull switch control knob rearward. If tester does not light, there is an open or short circuit in wire.
• Disconnect red, switch-to-motor wire from motor lead.
• Connect light tester to red, switch-to­motor wire terminal.
• Push switch control knob forward. If tester does not light, there is an open or short circuit in wire.

5. Checking the Motor Unit

1957 Buick Checking Motor Lead Wires

If a light tester indicates current at the motor lead terminals of the switch to motor wires but the motor unit does not operate from the switch, a final check of the motor unit can be made as follows:

• Check connection of motor ground wire to body metal.
• Connect a #12 gauge jumper from battery positive pole to motor lead terminal that connects to green switch-to-motor wire. The motor should operate to lower top.
• Connect jumper wire to motor lead terminal that connects to red, switch-to-motor wire. The motor should operate to raise top.
• If motor fails to operate on either or both of these checks, it should be repaired or replaced.
• If motor operates with jumper wire but will not operate from switch-to-motor wires, the trouble may be caused by reduced current resulting from damaged wiring or poor connections.

Hydraulic Checking Procedure

Failures in the hydraulic system can be caused by lack of hydraulic fluid, leaks in hydraulic system, obstructions or kinks in hydraulic hoses or faulty operation of a cylinder or pump. A pressure gauge can be used to check the pressure of the pump. See “Checking the Pressure of the Pump.”

1. Checking Hydraulic Fluid Level in Reservoir
   • Operate 1957 Buick Convertible top to raised position.
   • At the rear compartment, remove pump and motor shield.
   • Place absorbent rags below reservoir at filler plug.
   • With a straight-bladed screw driver, remove filler plug. Fluid level should be at the lower edge of filler plug hole.
   • If fluid is low, add Delco #11 hydraulic fluid (G. M. Hydraulic Brake Fluid Super #11) to bring to specified level.
   • Reinstall filler plug and pump and motor shield.
2. Checking Operation of Lift Cylinders
   • Remove rear seat cushion and folding top compartment side panel assembly.
   • Operate folding top control switch and observe the lift cylinders during “up” and “down” cycles for these conditions:
     • If movement of cylinder rods is not coordinated, or sluggish when the motor is actuated, check hydraulic hoses from motor and pump to cylinder for kinks.
     • If one cylinder rod moves slower than the other, cylinder having slower 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 “Checking the Pressure of the Pump.”

3. Checking Pressure at the Pump
   • Remove motor and pump assembly from rear compartment.
   • Install plug in one port, and pressure gauge in port to be checked, as indicated in figure 13-128.

1957 Buick Checking Pump Pressure

Removal of 1957 Buick Convertible Top Lift Cylinder

1. Remove rear seat cushion and seat back.
2. Remove 1957 Buick Convertible top compartment side trim panel.
3. Remove attaching nut, bolt, bushing and washer from upper end of cylinder.
4. Remove attaching screws from support at lower end of cylinder.
5. Move cylinder to gain access to hydraulic hose connections.
6. Disconnect and cap hydraulic connections on cylinder and on each hose.

CAUTION: Before disconnecting the hydraulic connections, place suitable wiping rags under the connections to absorb any drippage of hydraulic fluid. Also, disconnect the battery positive cable to prevent the accidental operation of the motor and pump while the hydraulic hoses are disconnected.

7. Remove cotter pin, clevis pin, spacer and support from lower end of cylinder and remove cylinder.
8. To install cylinder, reverse removal procedure with following exceptions: To aid in connection of cylinder piston rod to folding top linkage, use power to raise piston rod to extended position. Operate top down and up several times, then check and correct level of hydraulic fluid in reservoir.