Gas Gauge

[konrad]

Took the 51 for a short drive today, gas gauge said quarter tank, so stopped to fill up...was only able to get 3 gallons in before she was full.

Is it more likely a bad gauge, or the float mechanism?

[joefrazer]

It is always the sending unit. I would guess the float is full of fuel so you’ll need to drop the tank to repair.

[konrad]

If the float is full, do I need a new float, or is there a way to empty and repair it?

[Thomasso]

If the float is not rotted and has a small leak, often at the seam it can be repaired.  Drain with a small hole and dry completely then solder affected areas.

[konrad]

Many thanks guys!  Given the tank is full, guess I'll be doing a bit of driving before getting to that fix. 

[konrad]

Hmmm...Willow Run has an NOS sending unit for about $100 that has the correct gasket.

Vintage Auto Parts has a repro with plastic float for less than half that with free shipping, but no gasket...

My thought here is to just replace it, fix the old one at my leisure to have on hand as a spare if it's salvageable...

Without the gasket I think the repro is a PITA since I'd need to make one...guess I'll call the Larry's to see what they have. 

[rrdcorvair]

The one from Willow Run ( Chris in New Jersey) is a real good unit.  I may have spare brass floats -- but going through the trouble of dropping the tank, why not put a new one in?  The sending device on the tank unit corrodes and gets ify.  BTW, the 51-55 Kaiser gas tanks tend to refuse to accept gas at the speed pumps like to pump now and can make you think they'er full when they'll still take a few more gallons.  Learn to pump slow and listen to the filler neck.  Also, when the dash unit says full don't panic when after a few miles the gauge has free fallen to 3/4 or a little less.  They do that and then go down much slower.

[kaiserfrazerlibrary]

Another thing to watch for is the opposite.  The gage will move down to about 1/4 tank then just sit there until you run out of gas.  Floats can drop to the bottom of the tank OR stick at a point around the 1/4 tank level.  These things do corrode and depending on corrosion condition (where applicable) the crut will stop the float from dropping any further towards empty. 

Another thing that will throw off gage readings on a 1951-55 Kaiser is the condition of a tiny voltage regulator device attached to the wiring in the speedometer head.  This can easily be checked by (with engine running) turn on the headlights at bright.  If the temperature gage starts to rise significantly, turn the headlights off and watch the gage.  If it returns to normal operating temperature, the regulator should be replaced. 

Electrical components will deteriorate even if NOS because of how the ravages of time affect the innards.  I speak from 45 years experience with these cars.

PS:  Pre 1951 Kaisers and Frazers may have gas tank floats made out of cork rather thn the sealed floats.  These floats will deteriorate in today's 10% ethanol fuels due to the corrosive effects of the gasoline on the cork material.  Engineeers didn't have to contend with our current fuel mixtures when our cars were new or late model used cars so they did not design for the possibility.

[konrad]

BTW, the 51-55 Kaiser gas tanks tend to refuse to accept gas at the speed pumps like to pump now and can make you think they'er full when they'll still take a few more gallons.  Learn to pump slow and listen to the filler neck.  Also, when the dash unit says full don't panic when after a few miles the gauge has free fallen to 3/4 or a little less.  They do that and then go down much slower.

Noticed that right off, so slowed down the pumping.  The last tiny squeeze left the gas obviously showing in the filler neck about 1" below the opening, and it didn't go down...she was full.