Useable capacity of fuel safe tank/bladder for challenge racer

[peterjank]

Hello,

I have a challenge racer with the 22 gallon fuel safe tank and bladder. I understand that some capacity is lost to the foam installed within the fuel bladder. However, I would like to know how large that loss typically is. The useable capacity of my tank is approximately 16 gallons, implying a loss of 6 gallons.

[Jim Schenck]

Should be around 20.5 gallons if you pump it dry using the factory pump and then re-fill, some of the missing capacity left in the bottom as the check valves in the box aren't quite all the way down and some is in the foam. 16 gallons almost sounds like your check valves are stuck closed or the whole sump tank has shifted.

[peterjank]

Thanks Jim. I will check on the items you mentioned.