[DeTomaso] heater valve

[JDeRyke at aol.com]

There is in fact a tiny o-ring inside the heater valve. Some Pantera 
vendors carry it, as does McMasters-Carr in L.A. Bill Taylor's date base lists the 
source size & part number (I think).There are two different series of 
heater valve but the internal o-ring is the same for both. 
I don't think its possible to strip the valve with it installed in the car, 
so you'll have to remove it to replace the o-ring (once you have one in 
hand). Be VERY careful to 'back up' the attach nut to the heater tube when 
removing or replacing the valve. Even people who should know better have 
over-torqued the attach nut and cracked that ancient thin-wall copper heater 
tubing. Then the dash DOES need to come out. Cheers- JDeryke