Metro L3-61 1.0L (1990)
Fig. 3 Booster Piston Rod Adjustment
Single Diaphragm Type
This unit is used on late model GEO Metro & Spectrum. The length of the booster piston rod is adjusted to provide specified clearance between the
piston rod end and master cylinder piston. Before making an adjustment, push piston rod several times to ensure reaction disc is in place. Ensure gasket
is installed to master cylinder and keep inside of booster at atmospheric pressure.
1.
Place booster pin rod gauge No. J-34873 or equivalent on master cylinder and push pin until it contacts piston, Fig. 2.
2.
Turn tool upside down and place it on booster. Adjust booster piston rod length until rod end contacts pin head.
3.
Adjust clearance by turning adjusting bolt of piston rod, Fig. 3. If negative pressure is applied to booster with engine at idle, piston to piston rod
clearance should measure 0.004-0.020 inch.
AIR METHOD
1.
Be sure master cylinder attaching nuts are tight.
2.
Remove master cylinder filler cap.
3.
With brake released, force compressed air into the hydraulic outlet of the master cylinder. Regulate air pressure to a value of approximately 5
psi, to prevent spraying brake fluid from master cylinder. Care must be taken not to allow brake fluid to contact painted surfaces of
vehicle, skin or eyes, as damage or personal injury will result.
4.
If air passes through the compensating port, which is the smaller of the two holes in the bottom of the master cylinder reservoir, the adjustment is
satisfactory.
5.
If air does not flow through the compensating port, adjust the pushrod as required, either by means of the adjustment screw (if provided) or by
adding shims between the master cylinder and power unit shell until the air flows freely.
6.
Reconnect brake lines and bleed system.
