Posted by Mark V. (12.145.154.97) on March 15, 2005 at 14:12:17:
In Reply to: 1968 Miller-Meteor posted by Jason G. on March 15, 2005 at 13:03:56:
Well, assuming you're mechanically inclined, you're going to have to do some diagnostic work. To begin with, you should know the standard 1968 commercial chassis fuel tank only held 18gal. For the diagnosis we'll start with the obvious stuff first and work our way to the obscure. The most obvious thing to check is if you have the correct sized tank. Does the tank look like it may have been replaced at some point? For all you know, you could have a six-gallon tank. Take measurments of the outside and calculate what your volume would be. One gallon = 231.0 cu in. which means when you multiply the length, height and width it should equal roughly 4150 cubic inches (18gal).
If you're certain the tank is correct, check for obvious damage.
If there's no obvious external damage then try filling the tank slowly. I have a 1968 MM and I notice that when I fill the tank too quickly, the fuel backs up the filler tube and causes the nozzle to shut off giving the impression the tank is full when it's not.
If that doesn't work then remove the sender unit from the top of the tank and repair/replace it. This is a good idea regardless. The thing is a functioning gauge will tell you if your tank really is full or empty. The rest of the diagnostics can be done without a function gauge but it's a real drag.
With the tank "full", actually measure the fuel level in the tank by taking a rod and lowering one end of it into your tank where the sender would go and noting where the "wet" line is (this is where a functioning gauge would be helpful). Besure the end of the rod that's inside the tank is touching the bottom of the tank. When it's about time to fill your tank again (or when you're close to "empty") make another measurement as above and note the difference. I would guess there would be roughly a 1/3 drop in the level. This would indicate that the end of your fuel pick up tube is not positioned near the bottom of the tank. If the difference is extreme (like NO wet line) then that would indicate the volume on the inside of the tank is different from the apparent volume based on the external dimensions. In either case, you will have to drop the tank. You can do this yourself if you're mechanically inclined.
Good luck with your diagnostics and let us know if you need anymore help.
: My '68 Miller-Meteor 3-way coach has a strange problem I was hoping someone could help with. I've never been able to put more than 6 gallons of gas in the tank without the tank overflowing. I ran out of gas and still the tank will only take 6 gallons. The fuel gauge doesn't work but, the vacum lines and filler tube appear to be intact. Does anyone have any ideas as to what this could be before I have the tank removed?