70 headlight/wiper issues
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5th Gear
Joined: Oct 2012
Posts: 5
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70 headlight/wiper issues
I recently purchased a 70 454 automatic, and every time I started the car, the wiper door and headlight doors opened all the way, then closed. I repaired the vacuum lines at the override switches as they were leaking at the 90 degree connection under the dash. I also replaced the vacuum tank under the front fender as it was cracked in several places. These repairs helped but now when the car sits overnight, when starting the car the first time the wiper cowl and headlight doors still open slightly, (about 1/4 open) then close. The check valve seems to be holding vacuum. I did notice that the filter is missing by the intake manifold, but didn't think this would cause this problem. Any help or ideas on this problem would be appreciated.
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
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Thread Starter
5th Gear
Joined: Oct 2012
Posts: 5
Likes: 0
It is a new valve and seems to be holding vacuum. I did notice this morning that when I started the car the wiper cowl and left headlight only opened about 1/2 inch then closed, but the right headlight came all the way opened then closed, so maybe the leak is in that circuit?
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
Hi wb,
The system was designed with small hoses for the switches and relays and large hoses for the actuators so that on engine start up when the vacuum storage has leaked off, (over night for instance), the relays (small hose) will receive full vacuum (and stay in their present position) before the actuators (large hose) receive enough vacuum to operate their diaphragms (and open the doors). This system works because the small hoses/relays need less vacuum volume to work properly, so 'come on line' first.
I'd check for leaks in the small hoses, their connections, and the relays and switches.
Good Luck!
Regards,
Alan
The system was designed with small hoses for the switches and relays and large hoses for the actuators so that on engine start up when the vacuum storage has leaked off, (over night for instance), the relays (small hose) will receive full vacuum (and stay in their present position) before the actuators (large hose) receive enough vacuum to operate their diaphragms (and open the doors). This system works because the small hoses/relays need less vacuum volume to work properly, so 'come on line' first.
I'd check for leaks in the small hoses, their connections, and the relays and switches.
Good Luck!
Regards,
Alan
Last edited by Alan 71; Aug 21, 2013 at 04:53 PM.
