SPF radiator petcock

poboy427 · #1 (**permalink**) 01-11-2009, 05:27 PM

I have an older Cobra (#373 Sept '98) and have not been able to locate the drain petcock found on most radiators. Up till now I have just pulled the bottom hose to drain the rad. I want to install a Zinc Anode in the rad and the preferred spot is to remove the petcock and replace with 1/4 NPT zinc anode.

I hope I do not have to pull the fans and shroud to do this.

Any imput?

Ray

RedBarchetta · #2 (**permalink**) 01-11-2009, 05:53 PM

Ray, check for a threaded brass bung, driver's side, toward the bottom.

-Dean #747

PANAVIA · #3 (**permalink**) 01-12-2009, 12:15 AM

Beware : metric threads here.

Bill Wells · #4 (**permalink**) 01-12-2009, 06:10 AM

more beware:

as you discovered, older cars did NOT have a rad drain petcock , such as my 156 ( built in 1996) .only way to drain mine is by removing the lower rad hose and even then it is not completely drained . sounds like your scenario, you might be looking for something that does not exist .

Later build units ( and I dont know starting at which serial/chassis number ) had drain petcocks added as a running prodcution change . Bill

poboy427 · #5 (**permalink**) 01-12-2009, 05:33 PM

Thanks to all that replied.

Looks like my car is early enough that it does not have a petcock. Did see a fan thermostat switch a couple inches up from bottom of rad.

I wonder if there is a alternative way to introduce a zinc anode into my coolant system. For those that don't lnow this anode is designed to slowly carrode so the alum block/radiator doesn't. About every couple of years one would replace the anode.

I hesitate to screw one into the block in place of the block petcock as this could cause an obstruction or perhaps a hot spot.

Bill we have talked in years past on scof. I have been away for awhile over there.

Any ideas or thoughts on this. I have heard that a good ground strap from rad to frame will help.

Ray

Blas · #6 (**permalink**) 01-12-2009, 05:47 PM

Somewhere I saw someone with a radiator cap with an anode in the center of it...Just search "radiator cap with an anode" and their all over the internet...Let us know what you find and buy...

thudmaster · #7 (**permalink**) 01-12-2009, 08:43 PM

I know this is not helping you find it but boat owners have been using sacrafices for years. Check your local auto store Blas said. I bought one and put it in my Caddy; it was nearly gone in one year.

scootter · #8 (**permalink**) 01-12-2009, 09:45 PM

I bought one of the cap type ones from a place I found in the Drive magazine. I didn't fit right, so it keep leaking. It now sits in my box of spare parts.

Scott