How long should it hold?
Thread Starter
Racer
Joined: Feb 2001
Posts: 377
Likes: 0
How long should it hold?
How long should the vacume system hold, when the car is shut off? Meaning I can close the headlights for maybe 5 minutes after the car is shut off. Does that mean there is a leak.
Also, at a car show I saw a nice chrome reservoir (spelling) with a gauage built in at the tank, anybody using one of these?
Thanks
Also, at a car show I saw a nice chrome reservoir (spelling) with a gauage built in at the tank, anybody using one of these?
Thanks
Safety Car
Joined: Mar 2000
Posts: 4,078
Likes: 27
From: Northeast South Dakota
Re: How long should it hold? (Jon69L46)
I would think that a place to start would be to check your manifold vacuum. If you have much of a leak it will show up there. I don't know where to get a chromed vacuum canister, but I have probably the only polished 403 stainless vacuum resovoir in the world. Mine was broken, so I built one out of stainless.
Instructor
Joined: Feb 2000
Posts: 116
Likes: 0
From: Wilmington DE
Re: How long should it hold? (Jon69L46)
Guess another winter project has been added to my list. Once the 81 is shut off the headlights wouldn't even consider closing.
The winter project list keeps growing...... :rolleyes:
The winter project list keeps growing...... :rolleyes:
Le Mans Master
Joined: Jul 1999
Posts: 7,072
Likes: 4
From: Maryland
Re: How long should it hold? (Jon69L46)
Mine holds for a few minutes. Certainly not 5 minutes, but maybe 1 or 2 after the engine is shut down I can still close the headlights. Unfortunately I think the vacuum reservoir and heater core were the first 2 parts they put on the assy line before they built the rest of the car. Chris (69L71) tells a funny tale about how one of his frame off resto's started because of a leaky reservoir. :D ~Juliet
Racer
Joined: Jan 2001
Posts: 495
Likes: 0
From: ma
Re: How long should it hold? (Jon69L46)
Finished working on the vacuum lines and replaced the relays along with the check valve and filter after shutting down I can open n close the lights.other wise still have vacuum 24 hrs later enough to open the lights only.Before could not open with the engine off,did not find any major leaks,just alot of little ones that really seem to add up when they were combined together :cheers:
Thread Starter
Racer
Joined: Feb 2001
Posts: 377
Likes: 0
Re: How long should it hold? (Jon69L46)
Thanks for all the input. I noticed that the gauged tank was holding at about 10 lbs or what ever the measurement is, and I knew it was there all day. It got me to wondering!
Le Mans Master
Joined: Aug 2001
Posts: 7,804
Likes: 4
From: Standing still with all my might Texas
Cruise-In X Veteran
St. Jude Donor '09-'11
Re: How long should it hold? (Jon69L46)
There is usually enough vacuum to open the headlights on my car for about 30 minutes after shutting down. At about 4 1/2 hours after shutting off it completely leaks down and all at once I can hear the headlight actuators and the air selector door move. Every time I have heard this I have been out in the garage working on something and it always manages to surprise me! :eek:
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From: SE Pennsylvania
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Re: How long should it hold? (Jon69L46)
The vacume in the tank should hold for a few minutes, but if yours will hold for five minutes it's in perfect working order. Vacume is different than a pressure tank as it is very low vacume from the get-go, so it's not going to last more than a few minutes, and anyway it is really only used while the engine is running. My 79 has a solid leak-proof system and my vacume only hold for a few minutes after the engine is shut off.