[AT] float soldering

Jim and Lyn Evans jevans at evanstoys.com
Tue Feb 22 15:15:29 PST 2005


I pulled this advice off of a website for Model Ts.  I used this to repair a
float for a late Case SC carburetor float that is not available anywhere.
Suppliers were wanting $50+ for a USED float!  The float was about 1/2 full
of gas, now it is as good as new!  -- Jim  


Carb Float Fix

Many mechanics have been conditioned to ask for a float each time they
rebuild a carburetor, due to the reasonable price of modern, mass-produced
floats, and the propensity of nitrophyl (foam) floats to absorb gasoline
after time. In dealing with older, NON-CURRENT-PRODUCTION brass floats,
neither of the above are true, and a mechanic should attempt to 'save' the
float if at all possible.

The first step is to clean the float and inspect it for obvious damage.
Small dings and dents are quite common, even in unused floats, and occurred
when the manufacturer shipped the floats in bulk. Major dents (generally
caused by water freezing in the carburetor) are not generally repairable. If
one can hear liquid sloshing around inside the float, skip to the next
paragraph. If the float looks to be reasonably damage-free, it should be
tested. Testing is accomplished by grasping the float arm with a pair of
needle-nose pliers, and submerging the float in very hot water. The hot
water will pressurize the air inside the float, and a leaky float will blow
a stream of bubbles.

If the float should need repair, it is important to understand how the float
was originally produced. Virtually all brass float pontoons (the floating
part) are composed of two pieces (a few are more) of brass soldered
together. The pieces differ in the seam area, as one piece has a male seam
and the other a female seam. One float piece will also have a small hole for
temperature equalization. This hole will be covered by a small drop of
solder, and will be as far from the seam as possible. The manufacturer would
solder the two pieces together, allow the float to cool completely, AND THEN
close the equalization hole. Soldering MUST be done using a soldering
'iron'. Repair should not be attempted using either a torch, or a soldering
gun. If you plan on disregarding this advice, read the next paragraph first!
The following procedure works for us (no, we will not repair your float
unless we restore the entire carburetor): First, if liquid is present inside
the float, find the hole, and remove the liquid by placing the hole down
inside the hot water. The pressure will force the liquid from the float. If
the float has much liquid, it may be necessary to remove the float from the
hot water, allow the float to cool, and repeat the hot water dip. Once the
liquid has been removed, and the leak has been marked, open the equalization
hole by removing the solder. Solder the leak closed using as little solder
as possible. A small piece of tape over the equalization hole will allow the
hot water test to be preformed. If there are no leaks, remove the tape, and
ALLOW THE FLOAT TO COOL COMPLETELY before closing the equalization hole. A
final test, and you have 'saved' a valuable float.

There is usually a small pinhole somewhere else, not near the seam. First,
make sure the solder is off the hole, then do the seam, and when it's cool,
then solder the hole shut. Trick here is to keep the solder flowing onto the
hole sight while the air cools off, then it sucks the solder into the hole
instead of out of it. David D.




More information about the AT mailing list