Update on vacuum troubleshooting..Bad Tank??
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
Update on vacuum troubleshooting..Bad Tank??
Back in the thick of it after a few days out of town.
Today I completely isolated the vacuum tank. Approx 15" vacuum going in..nothing coming out of the other 2 ports. The tank has 3 ports on the rear of the tank. Middle port is connected to the manifold, upper to the left headlite relay, bottom to the T which goes to the right headlite relay, and to the wiper relay.
BTW, I routed vacuum directly to the wiper door, it works, albeit sluggish. I routed vacuum directly to the left headlite relay, then to the right relay...nothing.
My gut tells me the tank may be bad. Dont know how else to "test" it?
Any ideas anybody? Roger, chime in before I call you, I'll play around with it for a little while longer (so I like a challenge!)
Also, the one-way check valve has 15" on the big side, about 3-4" on the little side. So thats a problem I guess..I isolated the little (control) side today.
I'm about to start removing the drivers side lower dash, to install the Vintage Air unit, so I'll have better access to troubleshoot the vacuum system down there.
Thanks!
Today I completely isolated the vacuum tank. Approx 15" vacuum going in..nothing coming out of the other 2 ports. The tank has 3 ports on the rear of the tank. Middle port is connected to the manifold, upper to the left headlite relay, bottom to the T which goes to the right headlite relay, and to the wiper relay.
BTW, I routed vacuum directly to the wiper door, it works, albeit sluggish. I routed vacuum directly to the left headlite relay, then to the right relay...nothing.
My gut tells me the tank may be bad. Dont know how else to "test" it?
Any ideas anybody? Roger, chime in before I call you, I'll play around with it for a little while longer (so I like a challenge!)
Also, the one-way check valve has 15" on the big side, about 3-4" on the little side. So thats a problem I guess..I isolated the little (control) side today.
I'm about to start removing the drivers side lower dash, to install the Vintage Air unit, so I'll have better access to troubleshoot the vacuum system down there.
Thanks!
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Back in the thick of it after a few days out of town.
Today I completely isolated the vacuum tank. Approx 15" vacuum going in..nothing coming out of the other 2 ports. The tank has 3 ports on the rear of the tank. Middle port is connected to the manifold, upper to the left headlite relay, bottom to the T which goes to the right headlite relay, and to the wiper relay.
BTW, I routed vacuum directly to the wiper door, it works, albeit sluggish. I routed vacuum directly to the left headlite relay, then to the right relay...nothing.
My gut tells me the tank may be bad. Dont know how else to "test" it?
Any ideas anybody? Roger, chime in before I call you, I'll play around with it for a little while longer (so I like a challenge!)
Also, the one-way check valve has 15" on the big side, about 3-4" on the little side. So thats a problem I guess..I isolated the little (control) side today.
I'm about to start removing the drivers side lower dash, to install the Vintage Air unit, so I'll have better access to troubleshoot the vacuum system down there.
Thanks!
Today I completely isolated the vacuum tank. Approx 15" vacuum going in..nothing coming out of the other 2 ports. The tank has 3 ports on the rear of the tank. Middle port is connected to the manifold, upper to the left headlite relay, bottom to the T which goes to the right headlite relay, and to the wiper relay.
BTW, I routed vacuum directly to the wiper door, it works, albeit sluggish. I routed vacuum directly to the left headlite relay, then to the right relay...nothing.
My gut tells me the tank may be bad. Dont know how else to "test" it?
Any ideas anybody? Roger, chime in before I call you, I'll play around with it for a little while longer (so I like a challenge!)
Also, the one-way check valve has 15" on the big side, about 3-4" on the little side. So thats a problem I guess..I isolated the little (control) side today.
I'm about to start removing the drivers side lower dash, to install the Vintage Air unit, so I'll have better access to troubleshoot the vacuum system down there.
Thanks!
On your tank test block 1 port, attach your vacuum gage to one port, and to the other port run vacuum from the manifold.Start engine and see what the vacuum gage reads.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
When you are checking the ports on the check valve block the big port going to the tank and then check the small port.If the 3-4" goes up it is because the large port side is leaking.
On your tank test block 1 port, attach your vacuum gage to one port, and to the other port run vacuum from the manifold.Start engine and see what the vacuum gage reads.
On your tank test block 1 port, attach your vacuum gage to one port, and to the other port run vacuum from the manifold.Start engine and see what the vacuum gage reads.
On tank, with center port connected to manifold, top port (to left headlite relay) blocked, gauge on bottom port...I get MAYBE 2-3" vacuum...
So...check valve bad?? Tank bad??? Both?? This car sat for about 18 yrs without being started I was told..
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
With large outlet on check valve blocked, I get full 15" on small outlet.
On tank, with center port connected to manifold, top port (to left headlite relay) blocked, gauge on bottom port...I get MAYBE 2-3" vacuum...
So...check valve bad?? Tank bad??? Both?? This car sat for about 18 yrs without being started I was told..
On tank, with center port connected to manifold, top port (to left headlite relay) blocked, gauge on bottom port...I get MAYBE 2-3" vacuum...
So...check valve bad?? Tank bad??? Both?? This car sat for about 18 yrs without being started I was told..
On your check valve that test just told us it passes vacuum correctly.Your good there.
To test the check valve try to blow through the single port side-if you can its bad-but that is not a serious issue at this point-that check valve only retains vacuum when the car is shut off so you can operate headlights.
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
The tank is bad if you take it out you might be able to patch it.Its probably rusted in the bottom.
On your check valve that test just told us it passes vacuum correctly.Your good there.
To test the check valve try to blow through the single port side-if you can its bad-but that is not a serious issue at this point-that check valve only retains vacuum when the car is shut off so you can operate headlights.
On your check valve that test just told us it passes vacuum correctly.Your good there.
To test the check valve try to blow through the single port side-if you can its bad-but that is not a serious issue at this point-that check valve only retains vacuum when the car is shut off so you can operate headlights.
Thanks!
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
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Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
Thread Starter
Safety Car
Joined: Oct 2006
Posts: 3,993
Likes: 9
From: Gig Harbor WA
Well I'm makng progress. Got the left headlite to work great, with the wiper side of the system clamped off. The right lite is very weak and sluggish. With the line to the right headlite clamped off, I have good vacuum to the wiper relay, but thats all. No vacuum to the wiper door actuator. If I run a direct vacuum line to the wiper door actuator, the wiper door will move but very slowly...
Anyway, thanks to invaluable help from DWncchs, I feel like I may actually beat this demon!!!
Thanks Roger!!
Anyway, thanks to invaluable help from DWncchs, I feel like I may actually beat this demon!!!
Thanks Roger!!
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Glad your getting the bugs worked out.Its not too bad once you get the hang of it.Lots of hose pinching and isolating.
I diagnosed a 69 today and it had a bad wiper actuator,bad wiper relay and a bad headlight relay.System still worked but was real slow !!!
I diagnosed a 69 today and it had a bad wiper actuator,bad wiper relay and a bad headlight relay.System still worked but was real slow !!!
Melting Slicks
Joined: May 2006
Posts: 2,364
Likes: 103
From: Centerville Louisiana
You can use shaving cream on vacuum systems to pinpoint leaks thats what we use on large industial vacuum systems
