Headlight Vacuum Reservoir
Thread Starter
Instructor
Joined: Nov 2005
Posts: 238
Likes: 1
From: Oklahoma City Oklahoma
Headlight Vacuum Reservoir
A couple of months ago my Vacuum Reservoir (Coffee Can) got a leak. I found that the top section of the can was rusted.
I took the lines off and put a "T" connector on the lines and by passed the can. My lights still worked great, but of course they don't go up or down without the engine running and it takes a few seconds for them to work.
I decided to buy a new coffee can and received it this weekend. I replaced the bad can and hooked up the lines and started the engine to build up the pressure. After 5 minutes of running the engine, the headlights would not come up. I thought maybe it needed more time so I took her out for a 15 minute drive. When I returned home still nothing.
I took the lines off the can and put the "T" connector back on and the headlights went up and down with no problem. The line from the engine isn't as big as the headlight lines, could that be a problem, not getting enough vacuum for the can? I have vacuum on the line because it sticks to my finger, but I was wondering how much pressure should be coming from that line.
Does anyone know what's wrong?
I took the lines off and put a "T" connector on the lines and by passed the can. My lights still worked great, but of course they don't go up or down without the engine running and it takes a few seconds for them to work.
I decided to buy a new coffee can and received it this weekend. I replaced the bad can and hooked up the lines and started the engine to build up the pressure. After 5 minutes of running the engine, the headlights would not come up. I thought maybe it needed more time so I took her out for a 15 minute drive. When I returned home still nothing.
I took the lines off the can and put the "T" connector back on and the headlights went up and down with no problem. The line from the engine isn't as big as the headlight lines, could that be a problem, not getting enough vacuum for the can? I have vacuum on the line because it sticks to my finger, but I was wondering how much pressure should be coming from that line.
Does anyone know what's wrong?
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Try a Mighty Vac.
A couple of months ago my Vacuum Reservoir (Coffee Can) got a leak. I found that the top section of the can was rusted.
I took the lines off and put a "T" connector on the lines and by passed the can. My lights still worked great, but of course they don't go up or down without the engine running and it takes a few seconds for them to work.
I decided to buy a new coffee can and received it this weekend. I replaced the bad can and hooked up the lines and started the engine to build up the pressure. After 5 minutes of running the engine, the headlights would not come up. I thought maybe it needed more time so I took her out for a 15 minute drive. When I returned home still nothing.
I took the lines off the can and put the "T" connector back on and the headlights went up and down with no problem. The line from the engine isn't as big as the headlight lines, could that be a problem, not getting enough vacuum for the can? I have vacuum on the line because it sticks to my finger, but I was wondering how much pressure should be coming from that line.
Does anyone know what's wrong?
I took the lines off and put a "T" connector on the lines and by passed the can. My lights still worked great, but of course they don't go up or down without the engine running and it takes a few seconds for them to work.
I decided to buy a new coffee can and received it this weekend. I replaced the bad can and hooked up the lines and started the engine to build up the pressure. After 5 minutes of running the engine, the headlights would not come up. I thought maybe it needed more time so I took her out for a 15 minute drive. When I returned home still nothing.
I took the lines off the can and put the "T" connector back on and the headlights went up and down with no problem. The line from the engine isn't as big as the headlight lines, could that be a problem, not getting enough vacuum for the can? I have vacuum on the line because it sticks to my finger, but I was wondering how much pressure should be coming from that line.
Does anyone know what's wrong?
There needs to be a check valve in the small vac line from the intake - berfore the "T". Yes there is a small check valve and a small filter in the line. But u can test the entire system with a brake bleeder "Mighty Vac" tool - has vac gauge installed.
Try divide, isolate, check for leakage.
Happy hunting,
cardo0
Thread Starter
Instructor
Joined: Nov 2005
Posts: 238
Likes: 1
From: Oklahoma City Oklahoma
Thank you for your help.
For "Cardo0" - I'm not using a second one, I bought a new one to replace the rusted original can - it had a major leak. As far as the filter and check valve, mine doesn't have it. The line goes from the engine to the can without anything between. Should there be?
For "Cardo0" - I'm not using a second one, I bought a new one to replace the rusted original can - it had a major leak. As far as the filter and check valve, mine doesn't have it. The line goes from the engine to the can without anything between. Should there be?
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Cardo0,
On your 74 the reservoir is made I the front bumper “goal post” GM used this design until 1980 when they went to what we call the Folgers Coffee Can in 1980. The 1980 – 1982 cars used it with a mild variation in models. 1980 cars did not have a bracket on the can and 1981-1982 cars did.
This would explain the confusion.
Wagonerjim:
I would check the can and also check that you have the correct hose’s on the correct ports. If you have them wrong the can will not hold vacuum. http://willcoxcorvette.com/product_i...ducts_id=24616
Willcox Inc.
On your 74 the reservoir is made I the front bumper “goal post” GM used this design until 1980 when they went to what we call the Folgers Coffee Can in 1980. The 1980 – 1982 cars used it with a mild variation in models. 1980 cars did not have a bracket on the can and 1981-1982 cars did.
This would explain the confusion.
Wagonerjim:
I would check the can and also check that you have the correct hose’s on the correct ports. If you have them wrong the can will not hold vacuum. http://willcoxcorvette.com/product_i...ducts_id=24616
Willcox Inc.
Last edited by Willcox Corvette; Oct 25, 2007 at 08:49 PM.
Pro
Joined: May 2006
Posts: 573
Likes: 5
From: Georgetown Township MI
On my 1970, both headlights have there own vacuum relay.
Does your car have vacuum relays? If so, they may have gone bad?
If so, each headlight has its own. They are located under the front end -
Directly beneath the point of nose. All the vacuum lines for each
headlight assembly are routed to them. They are plumbed -
(Vacuum hoses and relay) are in a color corresponding order, like a stoplight.
Red on top, yellow in the center and green on the bottom.
Does your car have vacuum relays? If so, they may have gone bad?
If so, each headlight has its own. They are located under the front end -
Directly beneath the point of nose. All the vacuum lines for each
headlight assembly are routed to them. They are plumbed -
(Vacuum hoses and relay) are in a color corresponding order, like a stoplight.
Red on top, yellow in the center and green on the bottom.
Last edited by Rudy's Stingray; Oct 25, 2007 at 09:39 PM.
Thread Starter
Instructor
Joined: Nov 2005
Posts: 238
Likes: 1
From: Oklahoma City Oklahoma
Thanks Willcox, Your picture is the exact one I bought, but how is the best way to check the can?
I know I had the right lines on the can because there are two bigger tips and one little one. The lines from the headlights are big and the one from the engine is small. So I put the small one on the small tip and the two headlight lines to the larger tip. Correct?
Such a simple thing can be so problematic.
I know I had the right lines on the can because there are two bigger tips and one little one. The lines from the headlights are big and the one from the engine is small. So I put the small one on the small tip and the two headlight lines to the larger tip. Correct?
Such a simple thing can be so problematic.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
The best way to check this is with a mighty vac. or as described earlier.
Cover the two larger holes, and vac. on the small one.
You are correct with your hose's.
You can rule out the relay's, if they work direct they should work with the can.
Willcox
Cover the two larger holes, and vac. on the small one.
You are correct with your hose's.
You can rule out the relay's, if they work direct they should work with the can.
Willcox
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