Pulling and inspecting the screen in the high pressure housing on a W-670 is not a task one can look forward to. Although there isn’t much oil in the screen housing (maybe a half a pint), by the time the job is over, it looks like at least a couple of gallons have been spread around in the engine compartment.
After arriving home from the Galesburg trip, it was time to change the oil and inspect and clean the screens. The result was the usual one with oil from the screen housing spread all over the generator, the engine control rods and the bottom cowl. Even though I used the best technique that I knew about with the plastic bag.
So enough! A couple of days of examining the problem, trying different ideas and building a prototype resulted in the following “Special W-670 Tool”.
A piece of truck radiator hose, 1 & 3/4 inches ID, with a 90 degree bend at the 8 inch point is the basic building block. The one used here is a Goodyear XL # 65733
The right hand end with a few wraps of black tape is just the right size to screw on a two inch PVC cap. The stub end acts as a reservoir to catch and hold the oil.
At the point where the axis of the long tube intersects the 90 degree bend, cut in about a 3/8 in diam hole pointed directly at the open end of the tube on the left.
On the left end of the tube cut in a notch about 3/4 inch wide and 3/8 inch deep. This fits around the protrusion at the top of the screen housing.
Poke a 9 inch 3/8 drive extension through the hole in the bend toward the open end of the hose.
The hex nut on the end of the screen is 7/8 in. so get a 7/8 in, 3/8 drive socket. The brass hex nut has safety wire holes in two opposite corners. In order to connect the socket and the hex nut together so the screen can be pulled into the hose, you need to do the following. With a Dremel cutting disc, cut a 1/16 slot in the socket 1/8 inch above the edge, and parallel to the edge. This slot needs to be about 3/8 inch on each side of the inside corner on the socket that fits over the hex corner with the safety wire holes. This slot allows the insertion of a safety keeper pin through the safety wire holes in the hex and holds the socket in place on that hex.
Loosen the screen in the housing with the larger hex on the screen, two or three turns .
Now with the drive assembly inserted into the hose, engage the end of the 3/8 extension into the socket, and then push the hose over the end of the screen housing, with the notch at the top.
While holding a little pressure on the hose against the housing, unscrew the screen with the ratchet.
When all of the threads are disengaged, pull back gently on the ratchet while continuing to turn the extension. The screen will then be drawn completely into the hose.
Let it drain into the hose and reservoir for five to ten minutes and then remove the hose and screen as a unit. Put a rag in the housing hole while you inspect and clean the screen.
Pushing in on the extension will remove the screen from the hose. Do this over a pan in case any oil also gets pushed out. Pull the safety pin, and there you have it.
It is possible in pulling the screen back into the hose, to disengage the extension from the socket. Put it back in and be more careful. Or get an extension with a stronger detent.
The cap can be screwed off to clean the hose, and you need to tape the keeper pin to the socket so you can find it the next time.
I selected a Goodyear hose from the entire inventory of our local auto parts store. The number was XL 67533. It was a fairly long and complex hose that cost $20, but will probably make two tools. I’m sure that there are less expensive ones with the 1 3/4 in ID, but I wanted to get on with the project. The bend doesn’t have to be 90 degrees. 45 degrees would work just as well.
Radiator hose with cap and 3/8 extension
Socket attached to the hex with a pin through the slot and the safety wire holes
Socket, extension and ratchet shown without hose for clarity