Lotus Elan and Lotus Elan Plus 2 Forums

Hi All,
Advice needed please. My headlights go down OK, but do not stay down for long with the engine off. I have checked the pipe connections and crossmember for leaks and all seem OK , and i have got a new non-return valve at the manifold end.
I have now dismantled the solenoid valve as found the parts inside as per photograph.

Can any member confirm if this is a complete set of bits please

I think it must work that the spring pushes the ball (in this case green plastic,8 mm diameter) against the right hand rubber washer and seals the system so the vacuum build up and the lights retract. When the solenoid operates the rod extends and pushes the ball off its seat which collapses the vacuum in the headlamp pod ,so the lights come up. I assume the idea is that immediately after the ball leaves the right hand seal the solenoid rod pushes it onto the left hand seal, so that the vacuum in the cross member is retained.

What bugs me is that I do not see how the slackish rod from the solenoid can successfully push square onto the ball to seat it on the LH O ring. So have a got a part missing ?

Any help will be gratefully received,

Thanks and Best wishes,

Dick

I can't confirm but can you not test my just removing it?

Remove it and connect the two pipes together, run the engine to bring the lights down. Then see if they stay down. This should confirm if the solenoid is the issue it not.

You're aware that's not an original valve right?

The originals look like:


In fact this is Ted Taylors collection, which he has for sale at http://www.taylormadeclassiccars.com/partsselecttype/bodytypeparts.html

Have you bypassed the "T" that goes to the Chassis. Then tested again to prove that it's not a leak in the Chassis.
Alan

Looks like a different valve system has been mated to the coil ass. fitted to the Elan.
The vacuum valve is also fitted to the 75. Elite.
I am sure that these can be found at Mike Taylors Lotusbits
C.garde

It looks very similar to this one from a december 73 Elan +2S 130 pictured in a post here a few years ago... so maybe it is original and it looks like the OP's valve is complete.

Hi Dick130/5,
i used to have an August 1973 +2S130 and i replaced it with a new vacuum valve with viton seals 100%.
I still have a new one which i could sell to you. Where do you live.
Alan

I’ve usually figured that if the lights stay down with the engine running then the vacuum stuff all works and so it’s a matter of vacuum not being retained. I pulled vacuum on my chassis crossmember—fine; I tested that the solenoid valve worked, and tested that the pulldown single canister unit worked and came to the conclusion that all I needed was a decent One-way valve which I bought from Moss, part number 367-000. I know there’s one at least built into the system but it wasn’t doing enough. Gordon Sauer

`Dear mbell, Phil Harrison, Alan Barker, C.garde, Gordon Sauer.
Thanks gents for you very helpful replies.
I went though the tests as suggested and found that the main leak was at the T- piece into the front crossmember.
There is a very, very, slow leak through the solenoid valve but i think I can live with that.
I got fed up with waiting for the headlamps to move and put a vacuum gauge into the system to show any change in pressure,
I replaced the dud T-piece with 1/4 BSP Male to 5/16 barbed connector as photo. Bored out to 8 mm to fit the crossmember connection, and sealed onto it with a 1/4 BSP hose tail nut and 2 O-rings.
Pleased to see my vac valve original and complete.
Again , your assistance much appreciated.
Regards,
Dick