Elan Headlamp vaccum system

[Vanden Perre]

The vaccum command of the headlamps of my Elan (S3 Model from 1966)does not work properly. The headlamps retract when pushing the throtle. When lifting the throtle they come out again.
Has someone experimented the same problem ? Can someone halp me solving it ?

 

[coldplugs]

The first thing I'd check is the vacuum hose and connections between the engine and the front frame crossmember. If both headlights retract together when accelerating, the problem is probably there. Other possibilities include the headlight switch itself (the vacuum portion), the check valve near the front carb, and the front crossmember.

 

[Dave Thielke]

olivier
This was a common problem we had on some of the early elans and made for some exciting times on winding roads at night. Later, they changed the system so the headlamps were held up by springs and closed by vaccuum.
As coldplugs says, the most likely spot was the checkvalve at the front crossmember,which acted as a vaccuum tank, if I remember right.
Good luck and have fun.
Dave T

 

[Vanden Perre]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Dave Thielke:
olivier
This was a common problem we had on some of the early elans and made for some exciting times on winding roads at night. Later, they changed the system so the headlamps were held up by springs and closed by vaccuum.
As coldplugs says, the most likely spot was the checkvalve at the front crossmember,which acted as a vaccuum tank, if I remember right.
Good luck and have fun.
Dave T<hr></blockquote>

 

[Vanden Perre]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Dave Thielke:
olivier
This was a common problem we had on some of the early elans and made for some exciting times on winding roads at night. Later, they changed the system so the headlamps were held up by springs and closed by vaccuum.
As coldplugs says, the most likely spot was the checkvalve at the front crossmember,which acted as a vaccuum tank, if I remember right.
Good luck and have fun.
Dave T<hr></blockquote>

Thank you for your answer. I add a non return valve in the system and it is now working perfectely.