Another headlight actuator question
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,192
Likes: 111
From: If your not the lead dog the view never changes Boise, Id
Another headlight actuator question
The drivers side headlight on my 1978 decided to only open half way so I started trouble shooting. The rod seal on both actuators are apparently leaking because I can't even pull vacuume with my mityvac on the front nipple but when I hook up a constant vacuume source the light on the passengers side come up and the one on the drivers side will start and once again get about half way. When I test the back nipples at first I thought it was testing good but I noticed that it is actually leaking very slowly ( about 1psi per 90 seconds) so finally here is my question with the slow leak coming from the back ports do I need to find new actuators or can I still get away with new rod seals, I hear new actuators are iffy at best right out of the box. Thanx
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Before you spend money on something you don't need, verify that it will hold vacuum on the backside. If a actuator leaks on the front it can be fixed in most cases, but if it leaks on the rear side the diaphragm is toast as is the actuator.
Last edited by Willcox Corvette; Mar 2, 2016 at 11:47 PM.
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,192
Likes: 111
From: If your not the lead dog the view never changes Boise, Id
They both slowly leak from the backside about 1 psi every 90 seconds
Drifting
Joined: Jul 2006
Posts: 1,259
Likes: 154
From: Deplorableville Nebraska
When I test the back nipples at first I thought it was testing good but I noticed that it is actually leaking very slowly ( about 1psi per 90 seconds)
Many Mityvac and equivalent vacuum pumps leak down slowly themselves, and can give a false slow leak reading. Have you checked yours? Hook up a long plugged vacuum hose to it, and pump it up.
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,192
Likes: 111
From: If your not the lead dog the view never changes Boise, Id
If indeed the actuators are only leaking at a very slow rate, the constant vacuum supply will lower the headlights, and keep them closed tightly. The only downside to this is vacuum will leak out after shutdown if the rest of the system is vacuum tight. Front seals are easily replaced.
Many Mityvac and equivalent vacuum pumps leak down slowly themselves, and can give a false slow leak reading. Have you checked yours? Hook up a long plugged vacuum hose to it, and pump it up.
Many Mityvac and equivalent vacuum pumps leak down slowly themselves, and can give a false slow leak reading. Have you checked yours? Hook up a long plugged vacuum hose to it, and pump it up.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,852
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
If indeed the actuators are only leaking at a very slow rate, the constant vacuum supply will lower the headlights, and keep them closed tightly. The only downside to this is vacuum will leak out after shutdown if the rest of the system is vacuum tight. Front seals are easily replaced.
Many Mityvac and equivalent vacuum pumps leak down slowly themselves, and can give a false slow leak reading. Have you checked yours? Hook up a long plugged vacuum hose to it, and pump it up.
Many Mityvac and equivalent vacuum pumps leak down slowly themselves, and can give a false slow leak reading. Have you checked yours? Hook up a long plugged vacuum hose to it, and pump it up.
Put a check valve in line for testing actuators. You can get a cheap one from your local parts house. For the home shop it's a perfect solution to the mity Vac leak issue. Here is a link to one on Ebay. http://www.ebay.com/itm/BRAND-NEW-VA...lV8KPx&vxp=mtr
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Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,192
Likes: 111
From: If your not the lead dog the view never changes Boise, Id
Well slow leak does not appear to be in the mighty vac so I'm guessing it's the diaphragm in the actuators. I'm going to order the rod seal kit for both sides ( from Wilcox) and see if that will hold me over long enough to find the parts for electric openers.