Vacuum Problem
Thread Starter
Instructor
Joined: Sep 2007
Posts: 244
Likes: 3
From: Long Island
Vacuum Problem
I know there have been several threads about this, but I wanted a starting point from my friends on the forum. My headlights and wiper door are both suddening opening and closing veryyyy slowly when activated. What would be the most common point of failure for this. I have changed the white filter from the main vacuum in the intake and I have also changed the one in, two out gray check valve. What else could be causing both to be opening so slow. Thanks
Team Owner
Joined: Sep 2006
Posts: 31,112
Likes: 4,176
From: Westminster Maryland
Hi m70,
The headlight and wipers can be pretty frustrating!!!
If I may I'd like to suggest you purchase the light/wiper trouble shooting guide from Dr. Rebuild, and a vacuum pump with a gauge (like a MityVac).
These 2 things will allow you to test each component to see what's working and what isn't. I'll bet that the money you spend for those 2 things will save you from buying other unnecessary replacement parts.
It sounds to me like the problem is in the 'control' side, ( switches, small hoses, and relays) of the system, rather than the 'servo' side (actuators, large hoses), of the system, because it's unlikely the both sides, (open/close), of the 3 actuators would fail at the same time.
Have you tried using the 2 override switches under the steering column to see if there's any difference when they're pulled?
Good Luck!
Regards,
Alan
The headlight and wipers can be pretty frustrating!!!
If I may I'd like to suggest you purchase the light/wiper trouble shooting guide from Dr. Rebuild, and a vacuum pump with a gauge (like a MityVac).
These 2 things will allow you to test each component to see what's working and what isn't. I'll bet that the money you spend for those 2 things will save you from buying other unnecessary replacement parts.
It sounds to me like the problem is in the 'control' side, ( switches, small hoses, and relays) of the system, rather than the 'servo' side (actuators, large hoses), of the system, because it's unlikely the both sides, (open/close), of the 3 actuators would fail at the same time.
Have you tried using the 2 override switches under the steering column to see if there's any difference when they're pulled?
Good Luck!
Regards,
Alan
Last edited by Alan 71; Oct 2, 2012 at 06:37 PM.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Were they opening and closing slowly before you swapped out the white plastic check valve?
If memory serves, that a one way valve and it is possible to put it in backwards.
If memory serves, that a one way valve and it is possible to put it in backwards.
Melting Slicks
Joined: Apr 2007
Posts: 3,189
Likes: 111
From: Tolland CT
FWIW: I had the same problem last year. Turned out my vacuum relays were leaking, one severely, causing a large vacuum leak. They're pretty easy to test if you have a vacuum pump and a gauge. I replaced all three, headlights and wiper door pop right up now.
I'd first rule out the easy items as others have suggested, loose hose, check valve installed backward, etc.
What first sent me looking at the vacuum relays was when I was checking engine vacuum, motor running, I noticed the vacuum was a bit low. Starting at the intake manifold, I started pinching off the vacuum hoses at various points until I found one which made a significant difference. Turned out to be one routed to the front of the car, headlight actuator vacuum. Followed bit further, pinching it off at various points until I reached the vacuum relay. The vacuum relay seals do get old and will fail. There were a few threads last year where people were attempting to repair the originals, pictures showing what's inside.
I'd first rule out the easy items as others have suggested, loose hose, check valve installed backward, etc.
What first sent me looking at the vacuum relays was when I was checking engine vacuum, motor running, I noticed the vacuum was a bit low. Starting at the intake manifold, I started pinching off the vacuum hoses at various points until I found one which made a significant difference. Turned out to be one routed to the front of the car, headlight actuator vacuum. Followed bit further, pinching it off at various points until I reached the vacuum relay. The vacuum relay seals do get old and will fail. There were a few threads last year where people were attempting to repair the originals, pictures showing what's inside.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 244
Likes: 3
From: Long Island
Hi m70,
The headlight and wipers can be pretty frustrating!!!
If I may I'd like to suggest you purchase the light/wiper trouble shooting guide from Dr. Rebuild, and a vacuum pump with a gauge (like a MityVac).
These 2 things will allow you to test each component to see what's working and what isn't. I'll bet that the money you spend for those 2 things will save you from buying other unnecessary replacement parts.
It sounds to me like the problem is in the 'control' side, ( switches, small hoses, and relays) of the system, rather than the 'servo' side (actuators, large hoses), of the system, because it's unlikely the both sides, (open/close), of the 3 actuators would fail at the same time.
Have you tried using the 2 override switches under the steering column to see if there's any difference when they're pulled?
Good Luck!
Regards,
Alan
The headlight and wipers can be pretty frustrating!!!
If I may I'd like to suggest you purchase the light/wiper trouble shooting guide from Dr. Rebuild, and a vacuum pump with a gauge (like a MityVac).
These 2 things will allow you to test each component to see what's working and what isn't. I'll bet that the money you spend for those 2 things will save you from buying other unnecessary replacement parts.
It sounds to me like the problem is in the 'control' side, ( switches, small hoses, and relays) of the system, rather than the 'servo' side (actuators, large hoses), of the system, because it's unlikely the both sides, (open/close), of the 3 actuators would fail at the same time.
Have you tried using the 2 override switches under the steering column to see if there's any difference when they're pulled?
Good Luck!
Regards,
Alan
Thread Starter
Instructor
Joined: Sep 2007
Posts: 244
Likes: 3
From: Long Island
The white piece, I thought that was a filter. The grey, one in, two out I thought was a check valve
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
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