Last summer I noticed the coolant in my 89 TA looked rust colored so I flushed it out, then ran a cleaner though it and flushed it again. I took a look at it tonight and it looks as bad as it did last summer again. Its so bad that the inside of the reservoir tank is pure brown even when theres no coolant in it. What is causing this and how worried should I be?

 

Also the petcock on the radiator is leaking. I was just going to try to replace the petcock but would I be better off replacing the radiator? The radiator is aluminum, obviously, so I wouldn't think the rust is coming from there. Or is it?

 

have it flused at a rad shop, rust is from the block, they'll use a mild acid solution till its gone. rust scale could block passages in rad.

 

So is the block rusting from the inside not something to worry to much about?

 

i got the same problem when i took itin the said what look like mud came out of the rad

 

Do you have your cooling system grounded at either the heater core or radiator itself? There should be a ground strap on the heater core to firewall I believe. Without it, electrolysis will quickly degrade the coolant and make it caustic to the iron.

 

ima have to check because i dont know right now

 

think jcwhitney still sell the old rad caps with a bar of zinc to hang in the rad.

rust or what makes it is alive, if you give it zinc which is much easier to eat, it will eat it instead.

hotwater tanks have zinc rod in them for that, ships at sea bolt giant hunks of it to the outter hull.

 

or use a proper solution of antifreeze and distilled water.

those petcocks commonly fail and a new radiator is relatively inexpensive. inspect your rad and if it's crusted up, consider a new one.