Vacuum leak headlights
Thread Starter
Heel & Toe
Joined: Jul 2009
Posts: 19
Likes: 0
From: Pine Hill New Jersey
Vacuum leak headlights
Need a little help.
My engine was running a little rough and I figured it was a vacuum leak somewhere. I got out my "Stork" pliers and started to pinch-off some vacuum lines. I finally traced it down to the vacuum supply line for the headlight vacuum reservoir tank. To eliminate the headlight actuators and relays, I clamped-off the lines to them. Then I pinched-off the supply line right at the tank. The engine smoothed out right away.
I took the tank out and inspected it and found the outside clean and free of rust. I provided a little air to it and when I let go air quickly rushed out of the tank. This indicates to me that there must be some kind of internal "bladder".
Logic tells me there is an internal leak in the tank but I can't confirm it by spraying carb cleaner on the outside looking for leaks.
Has someone had this problem? I'm already a little bit nuts but this problem is making me worse . . .
Bill in NJ
My engine was running a little rough and I figured it was a vacuum leak somewhere. I got out my "Stork" pliers and started to pinch-off some vacuum lines. I finally traced it down to the vacuum supply line for the headlight vacuum reservoir tank. To eliminate the headlight actuators and relays, I clamped-off the lines to them. Then I pinched-off the supply line right at the tank. The engine smoothed out right away.
I took the tank out and inspected it and found the outside clean and free of rust. I provided a little air to it and when I let go air quickly rushed out of the tank. This indicates to me that there must be some kind of internal "bladder".
Logic tells me there is an internal leak in the tank but I can't confirm it by spraying carb cleaner on the outside looking for leaks.
Has someone had this problem? I'm already a little bit nuts but this problem is making me worse . . .
Bill in NJ
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
No bladder in there. Disconnect all the lines on the tank except the inlet from the engine. Install a vacuum gage at the outlet of the tank. Start engine and charge tank. Disconnect the vacuum line at the engine, if the check valve is good and the vacuum holds in the tank, it is OK. Most likely an actuator seal.
Gary
Gary
Thread Starter
Heel & Toe
Joined: Jul 2009
Posts: 19
Likes: 0
From: Pine Hill New Jersey
Thanks Gary.
My feeling is that it's not the actuator seal because when I pinch-off the line to it there is no difference. I pinched them both off at the same time . . .THEN pinched off the inlet. At that time the engine smoothed out
The idea about checking the vacuum at the tank sounds good. There is one inlet and 2 outlets to the relays. I'll disconnect those 2 and use a cap on one outlet and a gauge on the other. When I apply engine vacuum to the inlet, the can is supposed to hold vacuum when I disconnect the engine vacuum line?? If not then the can is bad??
I hope I've thought this out right. However I might be on to something.
Your help and diagnosis on what I just explained would be helpful.
Thanks,
Bill
My feeling is that it's not the actuator seal because when I pinch-off the line to it there is no difference. I pinched them both off at the same time . . .THEN pinched off the inlet. At that time the engine smoothed out
The idea about checking the vacuum at the tank sounds good. There is one inlet and 2 outlets to the relays. I'll disconnect those 2 and use a cap on one outlet and a gauge on the other. When I apply engine vacuum to the inlet, the can is supposed to hold vacuum when I disconnect the engine vacuum line?? If not then the can is bad??
I hope I've thought this out right. However I might be on to something.
Your help and diagnosis on what I just explained would be helpful.
Thanks,
Bill
Racer
Joined: Feb 2007
Posts: 331
Likes: 1
Yeah the vac systems on these cars can be difficult. A step back from the C2 cars design IMHO. Would like to meet the guy that decided to do away with the electric motors and use vac on the C3's Would kick him square in the stones.
I have one of the mightyvac hand vac pumps and assorted plugs and hoses and a troublshooting guide. Using these tools I was able to troubleshoot most of my issues but in the long run having ALL the old vac lines replaced with the factory replacement kit really made my vac system come to life. The 40 year old hoses leaked at the connection points on several actuators and relays because they were worn and stretched out so they didnt seal well anymore. They didnt leak bad enough to cause the engine to run poorly but they leaked enough to cause the headlights to open slowly. NOW the pop open firmly and at the same time. Really nice!
A sudden big leak that cause the car to run poorly like you seem to have though is usually a ruptured diphram inside a headlight or wiper door actuator like the above poster said.
You also need to confirm your check valve is good. It should be in the line from the main vac port on the mainfold.
I have one of the mightyvac hand vac pumps and assorted plugs and hoses and a troublshooting guide. Using these tools I was able to troubleshoot most of my issues but in the long run having ALL the old vac lines replaced with the factory replacement kit really made my vac system come to life. The 40 year old hoses leaked at the connection points on several actuators and relays because they were worn and stretched out so they didnt seal well anymore. They didnt leak bad enough to cause the engine to run poorly but they leaked enough to cause the headlights to open slowly. NOW the pop open firmly and at the same time. Really nice!
A sudden big leak that cause the car to run poorly like you seem to have though is usually a ruptured diphram inside a headlight or wiper door actuator like the above poster said.
You also need to confirm your check valve is good. It should be in the line from the main vac port on the mainfold.
Last edited by L Holmes; Oct 3, 2009 at 08:48 PM.
Racer
Joined: Feb 2007
Posts: 331
Likes: 1
One line in for vac from manifold, 1 line out to headlight actuators, 1 line out to wiper door actuator. So its probably and actuator, check valve, or the vac resivoir is cracked and leaking. Its real easy to plug the line to the wiper door actuator to confirm.
Thread Starter
Heel & Toe
Joined: Jul 2009
Posts: 19
Likes: 0
From: Pine Hill New Jersey
I don't have a "wiper door". My wipers are electric and have no door covering them. They're just there under the hood.
I have one inlet to the tank from the manifold that runs through a check valve up by the brake power booster and I have 2 lines going from the tank to dual regulators and dual actuators. One for each headlight.
If I've got it right, I'm checking tomorrow to se if the tank will maintain vacuum.
Thanks for your diagram.
Bill
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Safety Car
Joined: Apr 2000
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From: Wichita KS
Thanks Gary.
My feeling is that it's not the actuator seal because when I pinch-off the line to it there is no difference. I pinched them both off at the same time . . .THEN pinched off the inlet. At that time the engine smoothed out
The idea about checking the vacuum at the tank sounds good. There is one inlet and 2 outlets to the relays. I'll disconnect those 2 and use a cap on one outlet and a gauge on the other. When I apply engine vacuum to the inlet, the can is supposed to hold vacuum when I disconnect the engine vacuum line?? If not then the can is bad??
I hope I've thought this out right. However I might be on to something.
Your help and diagnosis on what I just explained would be helpful.
Thanks,
Bill
My feeling is that it's not the actuator seal because when I pinch-off the line to it there is no difference. I pinched them both off at the same time . . .THEN pinched off the inlet. At that time the engine smoothed out
The idea about checking the vacuum at the tank sounds good. There is one inlet and 2 outlets to the relays. I'll disconnect those 2 and use a cap on one outlet and a gauge on the other. When I apply engine vacuum to the inlet, the can is supposed to hold vacuum when I disconnect the engine vacuum line?? If not then the can is bad??
I hope I've thought this out right. However I might be on to something.
Your help and diagnosis on what I just explained would be helpful.
Thanks,
Bill
You test them by removing the red striped hose from the relay and connecting it to a vacuum pump with a vacuum gauge and monitor for leakage. Then remove the green striped hose from the relay and connect the vacuum pump to it and monitor for leakage.
If the connection to the red striped hose leaks the diaphragm is bad and you need to replace the actuator, if it doesn't and the connection to the green striped hose leaks you can repair the actuator by replacing the seal on the front of the actuator.
This was taken directly from Dr. Rebuild's vacuum troubleshooting guide.
cc
