replacing thermostat in '74 144

The thermostat in my 1974 144 has been sticking so I'm going to pick up an
IPD replacement and install it soon. Looks easy enough although I've never
done it before. Any install tips or hints? Do I need to drain any coolant
before I do it?

 

It really is about as simple as it looks- drain, remove hose, remove
two bolts/nuts, remove old, clean area, reassemble, fill, test. Here
are some general tips on replacing any thermostat:

1) be sure to have the correct thermostat and gasket on hand. If the
radiator hose(s) looks hard or feels stiff or "crunchy" when you
squeeze it, it might be a good time to replace it- check the rest of
the hoses as well. Now i9s the time to change them all if they need
it.

2) The coolant needs to be drained until below the level of the
thermostat. That should be less than a gallon in just about any car.
if you use either the block or radiator drain, when it stops flowing
you have drained enough and then some. Remember that nearly all
antifreeze/coolant is poisonous, particularly to pets who find the
taste sweet. Be sure to immediately clean up any spills and if
replacing the coolant to properly dispose of the used coolant at a
hazardous material recycler.

3) be sure to completely clean the mounting surfaces of the housing
and the block of all traces of old gasket. A Scotchbrite pad soaked in
a little coolant (or with a little WD-40 to remove old sealant) or
similar works great, but stuff a clean rag in the block before
cleaning so that none of the debris ends up in the cooling system.
Clean the mounting surfaces with some acetone, lacquer thinner, or
card cleaner on a rag before assembly.

4) You should not need any sealant, but if the surfaces of the housing
or block are damaged from previous gorillas or corrosion, try a thin
coat of RTV or aerosol Copper gasket sealant.

5) Be sure to put the thermostat in right-side up. Some can be
assembled upside down and they don't work well that way.

6) If you have an coolant recovery/overflow tank now is a good time to
remove it and clean it out so it is easier to see what's in it.

7) Be sure to follow the manufacturer's recommendations for refilling.
Usually that entails leaving the cap off the reservoir/radiator until
the car completely warms up, and refilling as necessary. This allows
air to escape. With newer cars, this is critical, and some even need
special procedures or equipment to refill the cooling system.
otherwise air can be trapped and the motor damaged (idiot
engineer/designers).

Hope that helps.

__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"

 

Thanks Randy, that was even easier than it looked in Haynes. The more I
work on this car the more I love it. I'm so glad thad I didn't sell it to
get that 242ti.