Re: Flushing Cooling system & Thermostat

[ggrunwald@domain.elided]

Nick

Two comments.

The drain taps on the block are replaced by brass plugs/bolts on the Mk2,
one on each sided of the block.  The bolts have fairly large heads, a
little like a sump plug size.  From memory the bolts are about half way up
the block under the exhaust manifold and the only way to see them is to
crawl under the vehicle.  When you take them out and flush you may not see
water coming out of the holes as many cars have sediment settled in the
cooling passages in this area and this can block the water passage near the
'plugs'.  Use a length of stiff wire to clear inside and you will soon get
a trickle of water and then a good flow.  Due to the position of these
holes the good flow is usually over your head so be prepared.  This is
exactly what happened to me last summer and consequently I intend to wait
to next summer, and a hot day, before I do it again.

If you are replacing the thermostat make sure you test the replacement one
in a saucepan of water on the stove before installing it.  Maybe the
thermostat the previous owner gave you does not work.  Even new ones can be
faulty.  Fifteen minutes effort can save a lot of time in the future, or
even your motor.

Guy Grunwald
77 Mk2