[DeTomaso] pressure and overflow tanks

[Larry Finch]

Robert,

First off, is your temp gauge checked for accuracy? OEM is likely not  
correct.

Infrared temp gun is the way to check this nowadays; or a kitchen  
thermometer in an open pressure tank.
Obviously, you start this procedure with an open tank and a cold car.

Second, is the 250 reading normal or new since your cap change?  While  
210-220 is not really a terrible thing, 250 is not exactly okay.

Next, have you moved the temp sensor from the OEM location in the  
pressure tank to the proper engine block port?

IIRC, 13# is correct for the pressure tank.  The overflow is not  
supposed to have a pressurized cap, just a cap to close it off.

Have you noticed any boiling-over or heard water boiling after engine  
shut off?

Larry