Re: how to change coolant

[Chuck Van Pelt <cvanpelt@aracnet.com>]

Peter,

What a timely question...I just changed my coolant this weekend in my 95
GLX. Here's what I learned:

DISCLAIMER: I am NOT a mechanic, but I do own a copy of the Bentley manual
for my car and consider myself to be a reasonably machanically capable
person.

What I used: Auto ramps, new VW approved coolant (which you have), lots of
distilled water (you can get this at just about any grocery store), nearby
hose & water supply, tools.

The Bentley manual says there is a drain plug in the tube that runs from
the water pump to the thermostat housing. I couldn't find this to save my
life. I drained mine from the lower radiator hose.

I drove my car up on ramps (set e-brake and chocked wheels) and
disconnected the hose running into the bottom of the radiator. There is a
single compression clamp holding it on. Squeeze open the clamp with pliers
and pull it off. Be sure to have a large (10+ quarts) container underneath
to catch the waterfall. Also, be sure to turn the heat in the passenger
cabin all the way to the "hot" position. This allows coolant to drain from
the heater core. Also, take the cap off of the coolant reservoir, otherwise
a vaccuum will form and the coolant will come out slowly or not at all.

Once the coolant has all drained, you can flush the system. It is a bad
thing to let coolant wash onto the ground...I let the coolant drain for
awhile before I flushed so very little was left. I then put distilled in
the coolant reservoir and began to refill the system without hooking the
bottom hose back up. I then started the car and continued to pour distilled
water "through" the engine to rinse out the gunk. Be sure to keep the water
flowing so you don't overheat your engine. If you end up getting raw
coolant on the ground, use your garden hose and rinse with LOTS of water.
The idea is to dilute the coolant so the neighborhood pets don't drink it.

Let the engine pump out the last of the distilled water...keep in mind the
there is actually a bit left in the heater core that the water pump won't
be able to pump out when the water level get's low. Turn off your car AS
SOON AS the coolant reservoir empties. Hook the radiator hose back up and
clamp into place. Pour your coolant mix into the coolant reservoir slowly
to allow air bubbles to escape. Once the reservoir is mostly full, I
started the car to begin to circulate the new coolant and force out the air
bubbles.

A note on coolant mixing: You can mix your coolant outside the car, or pour
each part (coolant and distilled water) into the coolant reservoir
seperately. The idea is to make sure you have a 50/50 mixture, or whatever
the coolant bottle specifies. Cooler climates might need a higher ratio of
antifreeze to prevent freezing in the winter.

If you put in too much water or coolant, here's a trick for fixing the
ratio without taking off the drain hose again: There is a recirculation
hose going back into the top of the coolant reservoir. Pull off this
connector and put it into a jar or other container that you have handy.
Have a buddy start the car and the coolant will start a-flowin'. Once you
have drained off some of the wrongly mixed coolant, replace it with either
straight coolant or straight distilled water (depending on the ration you
are trying to acheive).

Here's a bit of trivia for you...I understand that water is actually a
better conductor of heat than ethylene glycol coolant. (OK, so newer VW's
don't use ethylene glycol coolant, but I digress...) Technically, a
radiator full of straight water would better conduct heat away from the
engine, but water has the unfortunate tendency to freeze in the winter and
crack engine blocks. "Coolant" is added to reduce the freezing temperature
of the water below what even the worst New England winter can throw at you.

As far as where to take the coolant, mine is still in the sealed container
in my storage space. I believe you can take it to any quick oil change
place and they will dispose of it for you. (Maybe a small fee involved?) I
will be taking mine next weekend. Whatever you do, don't leave coolant
around in an uncovered container as it is very poisonous and it tastes
sweet so children and pets may be tempted to drink it.

Hope this helps!

Chuck Van Pelt


Peter Ziobrzynski wrote:

> Can somebody outline the procedure for changing the coolant in 97 Jetta
> GLX?
>
> I got one gallon of G12 from the VW dealer. I read the instructions on
> the container and understand I have to mix it 60/40 with distilled
> water. The main questions are:
>
> - where to dispose of the old coolant?
> - where is the drain plug?
> - where to buy distilled water?
>
> cheers...
> --
> Peter Ziobrzynski, mailto:pzi@pzi.net