Lotus Elan and Lotus Elan Plus 2 Forums

Been working on the headlamp circuits while engine was inop, & came up with a way to raise the headlamps without engine vacuum:Just plug your compressor line into the 'Air Input' end of vacuum tool, the car manifold vacuum line into the 'Vacuum' end of the tool, and the tool will immediately begin evacuating the vacuum tank, allowing the headlamps to be raised when selected on the headlamp switch. Not too spendy used, e.g.: http://www.ebay.com/itm/ROBINAIR-10970B ... SwqfNXl8mY
Works a charm.

Its just a venturi isnt it?

Chancer wrote:Its just a venturi isnt it?

yes - I'm not sure how deep a vacuum it can generate, but it probably uses a lot of air...

A hand pump like that used for single man brake bleeding (mityvac or the like) can also pump vacuum to some extent, I've used that in the past to pump a domestic air conditioning system and was quite satisfied with the result - it's quiet, too, so you can listen for leaks...

nmauduit wrote:

Chancer wrote:Its just a venturi isnt it?

yes - I'm not sure how deep a vacuum it can generate, but it probably uses a lot of air...

A hand pump like that used for single man brake bleeding (mityvac or the like) can also pump vacuum to some extent, I've used that in the past to pump a domestic air conditioning system and was quite satisfied with the result - it's quiet, too, so you can listen for leaks...

I have used a vacuum unit like this one in the past and yes, it uses a venturi to create the vacuum so it is very loud with all of the compressed air hissing out of the venturi. It is so loud you would never be able to hear a leak in your headlamp system while the unit was attached to your air compressor.

They do, however, draw a very deep vacuum and will actually evacuate the A/C system on your car prior to refrigerant charging. I used one of these units to evacuate the A/C system on my truck and after the recharge the A/C still blows cold nearly 20 years later!

This is as said a venturi device and is really loud. It does pull the vacuum tank down rapidly and fairly deeply, much more quickly than a hand-pump vacuum would--or possibly could, given a bigger leak. If you have a small compressor, this unit will make it a bit busy.

After repairs, I use it to quickly pull down an AC system, then switch over to a traditional electric vacuum pump to pull a seriously deep vacuum, something this unit isn't capable of.