Skylark L4-138 2.3L DOHC VIN D MFI QUAD 4 (1989)
Fig. 11 Power Head Assembly Exploded View. Delco-Moraine Tandem Diaphragm Booster
This unit utilizes a vacuum power chamber, consisting of a front and rear shell, housing divider, front and rear diaphragm, plate assemblies, hydraulic
pushrod and a diaphragm return spring, Figs. 10 and 11.
The unit operates in much the same manner as the single diaphragm unit described previously. The diaphragm and plate assemblies utilize the pressure
differential between the engine intake manifold vacuum and atmospheric pressure to assist in braking.
