Here in the next few days, I'm going to change the coolant in my 1979 Pontiac Catalina, replace the two radiator hoses and maybe the thermostat. The coolant is still bright green, but I doubt it's been changed in a pretty good while. The lower radiator hose is also starting to show some age.
I noticed the thermostat gasket is a Fel-Pro, the material is identical to the differential gasket I put in the same car the other day, as well as my truck. I haven't seen something like this before; would I use the same adhesive to seal the gasket as I did in the rear end? It seals against water and petroleum.
I remember Scotty blew the residual water and coolant out of his Matrix with a Shop Vac's outlet when he was flushing out the block. I don't have a Shop Vac with the outlet in the back. Can I use compressed air from my air compressor? I have one of those nozzles that will vent the compression to blow stuff off, like sawdust, etc. from the garage floor.
I always use a sealer (rtv) on the thermostat housing gasket just for quality. I also use my compressor to blow the old coolant out of the block (while the thermostat is removed and the heater is set on High.)
I usually use Permatex #2 on thermostat gaskets. When I put a new thermostat in my '99 Cherokee last year the Fel-Pro gasket already had beads of sealer on it. (Photo below.) Per the instructions I installed that dry and there have been no leaks.
I'll see if my gasket has sealer on it. Would you stick with the old school green coolant, or put a more modern formulation in that cast iron dinosaur?
Old school green - whatever is on sale.
I usually use WalMart "SuperTech" coolant in my older vehicles. (Since I'm a cheapskate I buy the concentrate and make a 50/50 mix myself with distilled water.)
I avoid using liquid gasket whenever possible. The stuff is a major PITA to scrape off the next time. I haven't had a problem yet using only gaskets. (including rear ends).
Can I use compressed air from my air compressor?
I wouldn't. Cooling systems are only designed to take about 15psi. Those compressors run at around 100psi.
I've always just flushed using a garden hose, with one end open (usually lower rad hose taken off).
How do you get the residual water from the hose out of the block?
I've since started using a 'T'
If you sketch out a diagram of your cooling system, it's a lot easier to understand what you're doing.
I finally got around to changing the coolant, hoses and thermostat today. It wasn't a bad job, everything's so convenient in this old tank, except that rear main seal. Haha. I've never done this before.
The original thermostat still works fine. I boiled water on the stove and dropped both the old one and the new OEM one in, they both work. Should I hang onto the original thermostat?
I noticed something Scotty pointed out with his Matrix a year or so ago when he did his coolant change and thermostat. The new GM thermostat is noticeably lighter than the original. I was surprised to see that it was still Made in USA, along with the radiator hoses.
I noticed the old lower radiator hose was looking like alligator skin in a big bend.