Vintage Mustang Forums banner

Removing thermostat

649 Views 5 Replies 4 Participants Last post by  FAQ
I'm replacing the thermostat and the housing tonight and flushing out the system. Instead of pulling the drain plugs on the engine or waiting for it to heat up to 180 degrees for the thermostat to open up; can I just pull the thermostat, flush the system, and put in the new one when Im finished?
1 - 6 of 6 Posts
Yes. Open the drain on the radiator, and that will get about half of the coolant out of the system. Add until full, start the engine, and drain it 1 or 2 times more to remove most of the old coolant.

If you truly are flushing the system, you'll need an open port for the incoming water, and an outlet port for the outgoing water. The radiator drain won't handle garden hose volume, though.
What about removing the bottom radiator hose? That should work?
the bottom hose is the inlet..remove it when you remove the T-Stat...put a garden hose into the bottom inlet and let it should flush all the junk out of the T-Stat port.but it is going to make a real mess..I would open the Rad drain plug..leave the T-Stat in..start the motor..and put a hose in the Rad, keep it running in the Rad filler neck..eventually the water will run out of the Radiator drain the way..turn the heater on high
Before you install that new t-stat, test it.

Put a few cups of water in a saucepan and put it on the stove. Heat up the water and drop the t-stat in. Make sure it opens the way it should. You can even use a meat thermometer to test the opening temp if you want.

Better to know before you install. That way, if you have an overheating problem after the install, you can eliminate that as a cause.
Thanks for your responses. I installed it a few hours ago and the car is running a bit cooler. The old 160 degree t-stat was covered with gasket sealer. I'm glad I got it out of the way and the new thermostat housing looks great.

1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.