Fixing the "Instant Reserve" Fuel Valve

Description: Fixing the "Instant Reserve" Fuel Valve

Author: awander
Date: Fri Jun 29, 2018 6:14 pm
Views: 2849
Category: Projects

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by awander » Fri Jun 29, 2018 8:14 pm

In addition to re-tipping fuel shutoff rods with PEEK, I recently had the opportunity to make and install a seat and a bushing for a valve that had neither.

I wanted to post some of the particulars here in case someone else wants to give it a try.
It was relatively straightforward to measure the IDs of the valve body, and I had a few complete valves to measure also,so I got a good idea of the dimensions that were needed for both parts.
I obtained some Aluminum Bronze round bar, and had a go. Here is my first attempt (they look a little rough, as the photo was taken after they were removed from the valve body):


Unfortunately, when installed in the valve body, the shutoff rod did not seal against the seat.

Looking at the valve assembly and shutoff rod, with no seat installed, showed that the tip of the rod was not exactly centered on the valve body. So, I figured I would need to install an undrilled seat, and drill and countersink it in place. To accomplish this, I made up a couple of "tool" bushings, to fit snugly in the upper diameter of the valve(where the shutoff rod bushing gets installed), and with through holes to fit a drill, a long center Drill,and the other end of the long center drill, which I ground to make a 90-degree countersink "D" bit.


This seemed to work fine-when I was done, the hole through the seat was quite off-center, so i installed the rod bushing, and tried it out.
Unfortunately, this one leaked as well. It seemed as if the installation of the actual rod bushing did not align the bushing exactly the same way as the temporary "tool" bushings I had used.

I removed the "off-center" seat and bushing-here is what they looked like, along with the tool used to drill and countersink the seat:


Here are a few other seats I tried, and as you can see, it looks like my countersink tool was not centering up very well on them:


FInally, I decided to make a tool that would cut the countersink, using the installed rod bushing instead of a "tool" bushing that would then be removed.
This is what the tool looked like-again, a simple "D" bit, with a 90 degree end, made from drill rod, relieved, hardened and tempered.


This one worked!

The valve body with new seat and bushing, along with the PEEK-tipped shutoff rod, are now on their way back to their owner.

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