1937 Dual Action Fuel Pump.
As far as I can tell, this is the only year for this pump.
Sit back and let me tell you a story about my trials and tribulations with this entertaining mechanical device.
I have spent 2 years finding the correct kit for this pump. Let me change that statement, I spent 2 years ordering parts for this pump and never did get
the right kit. I could never get the correct vacuum diaphragm.
The billows would fit the diameter and holes correctly but the center shaft would never be the right length. I had to duplicate my original shaft and put the new diaphragm on it.
Below is a picture of the pump breather, this is the area above the top of the lower vacuum pump.
The oil you see on the sod pans is not from this breather. Originally it had horse hair in this opening. I put in a thick plastic foam from a later model pump.
What I don't have is a picture of the bleeder hole on the left side of the pump just below the arm shaft retainer pin. That is where all the oil comes from.
Below is the beginning of my trial.
What you see is an oil baffle which was meant to keep oil from building up inside the pump.
37 is the only year with this pump arm. There are some better pictures further on.
According to the manual, and my personal experience, you need to have a (correct thickness) shim pack to get the correct pump throw.
Here is a link to the service manual I have online.
This I can attest to! You better have this correct or it will destroy your fiber cam gear.
I had the pump on once with not enough gaskets and you could watch the pump move on the block while the engine was running, hence putting undue strain on the cam gear.
It will also push the top of the pump cam arm up against the engine block casting, and you will get a clicking noise, see last picture.
I had to grind some off the top of the arm.
The best way to set up a pump on a 37 is to do it with the oil pan off and make sure you are not 'bottoming out' the pump.
Below are a couple of pictures of the baffle sitting in the pump housing casting.
Here is the Baffle away from the pump. As you can see the outline fits into the recess of the pump.
The square opening just fits the pump arm. You can see the top scraper in the below picture.
The hole in the bottom is a gasket flapper, picture above. As the pump works the idea was that this flapper would evacuate oil from the pump housing. The first fun part was to get this unit to stay in the pump housing because the pump arm would not allow it to stay centered in the recess of the pump body.
Here is the final story. After having every thing correct, the pump would fill with oil no matter what I did.
Final fix, left the baffle out, pump has not puked any oil since.
Yes....... It took me 2 years to figure this out. I was trying to stay tried and true to the Hudson way, but some things just didn't work.
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