vacuum # inches required for proper heater box operation!

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

olnick

Full Access Member
Joined
Feb 7, 2019
Posts
51
Reaction score
24
Location
Milford NH
First Name
Nick
Truck Year
1978
Truck Model
c15
Engine Size
1982 350 4 bolt mains
had the "blend door" vac can go bad replaced it checked all other functions/ installed back in truck ran all functions off of a vacuum pump. All systems worked as expected with selected option on heater control. Now with the engine vacuum hooked up none of the controls work? best I can get at the vacuum canister is 15# inches? Nothing else changed just the bad can prior to that the heater control worked fine? Is the vacuum can supposed to have a 1 way valve to hold/maintain the vacuum with the engine off? Mine does NOT.

Olnick
 

sidschev

Full Access Member
Joined
Oct 2, 2023
Posts
280
Reaction score
500
Location
Arkansas
First Name
sidney
Truck Year
1984
Truck Model
c1500
Engine Size
350
:popcorn:
 

fast 99

Full Access Member
Joined
Dec 31, 2021
Posts
1,644
Reaction score
2,235
Location
Spokane, Washington
First Name
Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
I don't believe those cans hold vacuum but could be wrong. 15" what is intake vacuum, that is somewhat low and may be indicative or a vacuum leak.
 

Forum statistics

Threads
42,237
Posts
911,920
Members
33,739
Latest member
michaelmarine53
Top