Replacing the thermostat

[firstq]

Guys, any best practices and recommendations on doing this on my 92Q45 -

1. Do I really need to drain the coolant before removing the hose over the thermostat assembly...

2. Any specific RTV to use? The dealer recommended getting one from autozone for half the price, any names you folks have used with success?

Thanks

[DAEDALUS]

Well, you don't have to drain the coolant, but if you don't, you'll open the floodgates as soon as you remove the radiator hose on the cover and/or remove the tstat cover itself. I assume you're concerned about having to open the drain plugs. Not a big deal--mine were frozen too. Drain as much as you can via the radiator, and just be ready with a bucket and high pressure hose to catch and clean up the stuff that leaks out when you pop the cover. Pets like the taste of coolant, but a little will kill them, so don't let any sit around. Permatex makes a pretty robust product line of RTV--very available. The blue stuff is easy to work with and should be fine for coolant temps. Make sure you clean and degrease the mating surfaces very well before reassembly.

[Q451990]

I've used permatex grey for the thermostat housing, valve covers, etc... seems to work well. I'd go ahead and order the hose that connects between the thermostat housing and the metal tube that goes between that hose and the lower radiator hose. I had to cut it and and then use an aftermarket hose with less than stellar results...

If you have high mileage and it's never been done before, you may want to replace the t-stat housing and the tube. The housing and metal tube are actually a sacrificial annode that are designed to corrode and prevent deterioration in other areas of the system. An old tube will look like there are barnicles growing inside it!

Heath