do i have to drain the radiator fluid and refill again to change the thermostat? i just had that done last fall, and i really dont want to do it again just to put in a thermostat

 

absolutely not.

Just unhook the one hose that runs into it, you might want to stick some rags by the intake as a little bit of antifreeze will come out and the two bolts and the housing is off.

No need to drain it though

 

As soon as you remove the upper hose or thermostat housing, you'll lose about a half gallon (oh, I'm sorry - a couple liters) and have it drooling all over your engine. It would be easier, neater, and probably less expensive to place a clean drain pan under the readiator petcôck and drain a gallon or so before starting the project, then pour it back into the radiator and reservoir when you're finished.

 

hmm, I just changed my 192 therm to a 180 stant and had no such as but maybe a pepsi can full of antifreeze come out

but if vader says so, I would drain it!

:hail:

 

What size Pepsi can? I don't know everything, you know. I'm here to learn like the rest of us.

You may not lose a lot. but if the system is filled to the top of the radiator neck, you're going to lose some. If you don't mind woking in stick, slippery antifreeze, that's O.K. Just make sure you clean up all the spillage and get a clean, dry gasket surface before you reassemble.

And don't forget the anti seize compound on the bolts. If you break one off trying to remove the thermostat, you'll know why.

 

The first time I did a theomostat, I didn't drain any antifreeze out. When I pulled the gooseneck off I lost enough antifreeze to get the ground pretty wet under the car

I second the notion about the antisieze too, you won't regret it next time you have to get in there

Matt