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Narrow Tube - Will This Pump Work?

Narrow Tube - Will This Pump Work?

Narrow Tube - Will This Pump Work?

(OP)
I'm a partner in a small electronics design company.
We design test instruments that are frequently one-
of-a-kind. Our biggest client makes all sorts of
lubricants.

Every two months one of us unluckly guys visits our
clients fleet of cars and vans. We randomly choose a
vehicle and extract a quart of motor or transmission/
transaxle oil through the dip tube. The oil is put
through hundreds of tests.

For years we used various hand pumps. Its a slow and
tedious process. We tried a couple of cheap electric
pumps that failed miserably.

Here's a pump that I might buy:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_47671_47671

It has 3/4" inlet and outlet ports. Obviously, a reducer
will have to be used on the inlet port. We typically use
a 1/4" or 3/8" polyethylene tube. Nothing larger will fit
down an oil dip tube.

By restricting the input to this pump, will it still be able
to siphon the motor or transmission oil? In this case, the
GPM rating is not important. A slow trickle of oil is fine,
as long as it keeps pumping!

RE: Narrow Tube - Will This Pump Work?

Here is what I use to remove oil from my boat engine.  It is a vacuum pump.  You pump a vacuum with a few strokes of the pump, then wait for the oil to be drawn out of the engine into the canister.  It is not fast, but it beats manually pumping the oil.

http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/268534/377%20710%201679/0//Primary%20Search/mode%20matchallpartial/0/0?N=377%20710%201679&Ne=0&Ntt=&Ntx=mode%20matchallpartial&page=CategoryDisplayLevel1&isLTokenURL=true

Ted

RE: Narrow Tube - Will This Pump Work?

You might try different tube material, e.g. nylon.

Not that the material has any magical properties, just that a thinner wall can still support a vacuum without collapsing.

What you need for a dip tube is something that will just barely fit in the dipstick tube, and has a wall thickness as close to zero as you can get without making the tube easy to collapse, because the bottleneck, so to speak, in the thieving process is the inside diameter of the dip tube.

 

Mike Halloran
Pembroke Pines, FL, USA

RE: Narrow Tube - Will This Pump Work?

One of the pumps from West Marine has a garden hose fitting that connects directly to those engine dipstick tubes that have the male garden hose thread on the end.  Requires no tube to be fed down the dipstick tube.

Ted

RE: Narrow Tube - Will This Pump Work?

(OP)
I've never seen a motor vehicle that has a threaded
connector at the end of the dip tube. It may be common
in marine applications. Has anyone ever seen a car,
truck, van, or SUV that has a threaded connector at
the end of a dip tube?

You guys have given me an idea. As usual, I should
have resolved this problem years ago. All of us are
suppose to be super smart!

If I could find some moderately flexible hose, in
a few different diameters that would fit easily over
most dip tubes, that would resolve the problem. The
hose could could be secured with a simple strap clamp.
Remember, our goal is not to drain the motor or
transmission oil pans. All we want to do is extract
one quart for testing. (We always add a fresh quart
to replace the quart that was extracted.)

I've got a closet full of hand pumps that we all hate.
Any of them would probably work fine if a hose was
clamped over the dip tube, instead of shoving a narrow
tube down the dipstick tube.

RE: Narrow Tube - Will This Pump Work?

Restrictor,
Don't get too excited, I reckon that you will still need to immerse a tube in the fluid.  Otherwise, you will simply be lowering the air pressure uniformly within the transmission housing without being able to "lift" the fluid into the dip tube.

RE: Narrow Tube - Will This Pump Work?

There is a note on the linked website that it 'cannot be used for waste oil'. Oil that has seen service in an engine is at some point on its journey toward becoming waste oil. Might be worth checking why this restriction is applied.

Bill,

Doesn't the dip tube extend below the surface of the oil? Provided this remains the case with a quart removed from the sump, a little self-priming pump should be able to deal with a few (10?) inches of suction head. The idea sounds like it is worth a try.
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

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