Mechanical fuel gauge calibration

Ask Questions and Offer Advice Related to the Cessna 120 & 140 Type

Moderators: 6643, 6183, V529

Forum rules
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
Post Reply
6555
Posts: 19
Joined: Sun Jul 15, 2018 7:32 pm
Name: John S
Aircraft Type:
Occupation-Interests:
Contact:

Mechanical fuel gauge calibration

Post by 6555 »

Hello all:

In an earlier post I stated that my gauge was leaking and staining the headliner (thanks for all the help). I did locate the gasket at Spruce (you have to enter the part # in the search by part # box or it won't show up). So I got the gasket (rubber not cork I hope that's OK) removed the gauge, and found the magnet that moves the needle on the gauge is spinning freely, and is no longer connected the shaft so its basically doing its own thing and has no connection with the float (I have rubber floats apparently someone replaced the cork).

So my big question is can you epoxy the magnet to the shaft so they work in unison to give you an idea of the fuel in the tank, and if so how do you calibrate it so it is somewhat accurate. I considered laying it out so the float is roughly straight out on a work area then moving the magnet to the 1/2 tank indication and then securing the magnet to the shaft. Im not sure if that is a good plan or not, thanks in advance for your comments.
User avatar
6643
Posts: 2340
Joined: Tue May 01, 2018 7:00 am
Location: KLCI
Name: John C
Aircraft Type: 1946 C140/C90
Occupation-Interests: A&P, semi-retired
Contact:

Re: Mechanical fuel gauge calibration

Post by 6643 »

Well, there is are requirements for the calibration. The gauge must read empty when the tank is empty, and it cannot read full unless the tank is full. (Note that a gauge that always says "E" would meet the requirements.)

So, figure out where it has to be to read empty a little before the fuel runs out completely, and set it there. You can fine tune it by bending the arm slightly.
Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 20 guests