Headlight problem (about to wink...)

[Peer81]

Hello everybody,

I think it's a simple problem but I just don't have the time to check the entire vacuum system step by step.

What is the problem? Till last week nothing but now when I turn on the headlights the pass. headlight wants to come up but stops 1/3 up and slowly goes back down. The drivers side stays down. When giving them a hand they both will go up and stay there. When I turn the lights off they both go down if I remember correctly.
With the engine idling I get a steady vacuum reading from 20 to 21Hg. When I turn on the lights vacuum drops around 3 to 4Hg. When I disconnect the vacuumline from the override switch (before the actuators) the vacuum reading is only 10Hg so I have a vacuumleak that is sure.

Now I replaced all the vacuumlines a few years ago, same for the filter and metal check valve. The vacuumtank, relays are original. The actuators have new seals but thats it. Also when putting a vacuumpump before the relays, I see the relays (top side) will hold vacuum perfectly.

Next thing I want to check is if the actuators will hold vacuum.
If somebody has another idea please say so

Greetings Peter

 

[KOPBET]

This may help. Especially since you have a vacuum pump. Vacuum Troubleshooting . I suspect the relays, since when they wear out they leak vacuum.

 

[hotmtrsports]

You have no choice but to troubleshoot step by step. You'll only get guesses here. Good guesses, but by the time you try what is suggested...your time would have been better spent just doing it right. No way around this one.

Unless you get lucky with the 1st few suggestions...

The Vacuum Troubleshooting link KOPBET sent you is a fantastic source!

Chuck M

 

[6880 Mike]

Vacuum relay for the passenger's side. If you're lucky, it won't me anything more than that.

 

[Peer81]

Hello everybody,

Thanks for the replies! I'll just go over it step by step to see what the condition is of all the components.
@Kopbet, perfect link for troubleshooting the vacuum system thank!

Greetings Peter

 

[Peer81]

I had some time today so I went ahead with the vacuumpump and the vise grips.

First the metal ports on the relay valves hold perfect vacuum and move good and fast up and down.
With the green port blocked the yellow port doesn't hold vacuum (both relay valves)
With vacuum on the metal port and the red port blocked the yellow port still doesn't hold vacuum (again both relay valves). I already opened up both relay valves and I'll go from there, I have to say on the inside everything looked very nice.

When blocking both yellow hoses from the vacuum reservior tank and putting vacuum on the 3rd hose vacuum was lost very very slowly. I would suspect as I still had all the vacuumlines attached to it that could also cause the little vacuum leak. I'll just leave that as it is right now.

The actuators. The passangers side actuator is working perfectly with steady vacuum on both the red and the green hose.
The drivers side actuator holds vacuum on the red hose but is loosing vacuum fast on the green hose. I suspect the grommet that needs to be replaced. I still have two on the table so no problem.

I still need to test the , pulldown swith, headlight switch, filter and check valve so I know for sure these are the only problems.

Greetings Peter