chevrolet Workshop Repair Guides

Chevrolet Workshop Service and Repair Manuals

Transmission Vacuum Regulator Valve <--> [Shift Modulator]|Description and Operation|Page 2811 > < Transmission Vacuum Regulator Valve <--> [Shift Modulator]|Description and Operation
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Transmission Vacuum Regulator Valve: Adjustments

Fig. 39 Installing vacuum regulator valve gauge bar

1.

Attach vacuum regulator valve to injection pump. Vacuum regulator valve should be attached snugly without being over-tightened.

2.

Attach vacuum gauge to outboard vacuum nipple on 1982 models, or top vacuum nipple on 1983---87 models.

3.

Attach vacuum source to inboard vacuum nipple on 1982 models, or bottom vacuum nipple on 1983---87 models, then apply 9.0---10.4 inches Hg
vacuum on 1982 models, or 18.5---21.5 inches Hg vacuum on 1983---87 models, to nipple.

4.

Open stop screw on throttle lever to fully open position, then insert 0.646 inch vacuum regulator gage bar between gage boss on pump and stop
screw, Fig. 39.

5.

Rotate and hold throttle shaft against gage bar, then slowly rotate regulator body clockwise until vacuum gauge reads 5.3---5.9 inches Hg on 1982
models, 7.4---8.6 inches Hg on 1983---86 models, or 10.9---12.1 inches Hg on 1987 models. Hold body in this position, then torque mounting
screws to 4 ft. lbs.

6.

Allow throttle shaft to return to idle position, then repeat Step 5. Readjust valve if necessary.

Transmission Vacuum Regulator Valve <--> [Shift Modulator]|Description and Operation|Page 2811 > < Transmission Vacuum Regulator Valve <--> [Shift Modulator]|Description and Operation