E 100 Van V8-302 5.0L (1983)
Vacuum Tank: Description and Operation
Fig. 37 Vacuum reservoirs
The vacuum reservoir, Fig. 37, used on some vehicles, acts as an accumulator and prevents sudden drops or rapid fluctuations in a vacuum signal during
acceleration. If vacuum in the reservoir leaks more than 1/2 inch Hg in 1 minute, the reservoir is defective and must be replaced.
