marshal135

hello everyone,
I used my miti vac to test the rear ports, red line connection on both of my actuators.
I pumped them up to about 25 inch lbs. In about 30 minutes I went out and rechecked them. They had dropped to about half like 11-15 inch lbs.
I know the back port keeps them down and if the large diaphragm is shot they are not rebuild able. I can pump the tool and get them to raise and lower. When I start the car the drivers headlight and wiper door raise for several minutes then lower themselves.
The front port on both at the green hose connection was bout the same loss.
Before I replace the front seals and have to do the job twice my ? Is should the rear port hold vac indefinitely?
If I replace both actuating units as an assy can expect the same loss or will they hold as long as vac is present?.
I purchased both front seals and was going to replace maybe over next week but got to thinking I better ask here first so I don't have to do the job twice.
Thanks,
Marshal

8VETTE7

This can't be a C5 issue. Did you post in the wrong Forum???

marshal135

Sorry c5 guys I posted in wrong section hopefully moderator will catch and move to tech sect in c3 and I will receive 2 demerits for such behavior
Thanks,
Marshal

Tact

Dave J

This is normally the fault of the relays. You have a Mityvac, use it to check them. Simply connect it to the middle port on the relay, block the lower port, and pump it up. The relay should hold vacuum. What causes the winking headlights is the relay is leaking vacuum internally around the seals, and the actuating vacuum is just following that path around the internal piston.

The small loss of vacuum at the actuators you're experiencing would not cause the problem. At the rate of vacuum loss you have, check the Mityvac with a section of blocked hose only to verify it's not leaking past it's internal seals.

marshal135

Dave,
Thanks for the response.
I recently replaced the two actuator relays.
68 has 1 for the head light actuators and 1 for the wiper doors.
It doesn't preclude that one could be leaking
I'll also verify the miti vac is not leaking internally.
Thanks,
Marshal

texaswilkins

I tried resealing mine and still ended up replacing them. When you do replace them make sure the vendor you choose sends you a matched pair. The right angle ports on the back side should point in opposite directions. The vendor I chose sent me two lefts and wouldn't make it right.

Bill

marshal135

Bill,
thanks for the heads up on the left and right actuators
Hopefully who ever I order from gets it right.
But at least I know now to look for it.
Marshal

Alan 71

Hi Marshal,
My understanding is that:
First the green hose, (straight port,) should be disconnected. If the vacuum holds on that port the internal diaphragm is good. If it doesn't hold the vacuum, the internal seal is leaking… and there is no repair.
Then disconnect the red hose, (curved port), and the vacuum checked at that port. If the vacuum holds and then drops, but was better, (lasted longer), on the green hose's straight port, the small rear sealing grommet should be replaced.
Given the length of time your actuators are holding the vacuum I think replacing the small seals are worth the try.$$$
Regards,
Alan

marshal135

Alan,
Thanks for providing the correct procedures for testing the actuators.
I did it incorrectly. I tested each port with the other line still attached.
Thanks
Marshal