MB,

The easy way to check if the Hydrovac is working is with the truck off depress the brake pedal with medium pressure. While holding the brake start the truck...if the Hydrovac is working you will feel the brake pedal fade away a little bit.

Take care,

Mike B smile


Mike Boteler

1956 Chevy 3100 Resto Rod
1952 Willys M38 Army Jeep
1983 Jeep CJ7 Laredo
1984 Jeep CJ7
+++++
Silver Spring, MD