Date: Thu, 14 Mar 1996 09:12:11 CST6CDT
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: "Dan Houg" <fairwind@northernnet.com>
Subject: Rad flushing musings
Dear Hosers (and especially Tim):
Having experienced reduced heater output, possibly from liberal additions of
BarsLeak and AlumaSeal i will be flushing cores this spring. Here
are some thoughts:
You can do just the cores themselves. I've done this on both my '85
and the '87. I do this because the thought of gallons of 'aggressive
cleaners' circulating thru my leaky system makes me nervous. It is a
little equipment intensive but with some scrounging most people have
enough junk around to accomplish this. well, if you live like
someone akin to Red Green (who will be in Bemidji on Saturday).
-disconnect heater hoses as they attach to engine. location varies
by year but are fairly easy to get to.
-hook up a circulating pump, a vat in which you can heat a large
quantity of liquid, and a propane burner. i use a 10 gallon boiling
vessel, a 170K BTU burner, and a 12v pump.
-fill the keg with a few gallons of water, dump in your favorite
chemical, light the burner, and let this circulate a few hours.
-flush well with clear water.
-lastly, i have a garden hose adapter that also allows bursts of
compressed air to be shot in the water stream for dislodging
contaminants. it has a stepped nozzle for fitting a variety of
heater hose diameters and a schrader valve to jet the air in with a
tire chuck. it seems to loosen some crud.
this has worked well for me, though it borders on techno-geek. the
service manager at VW here in town asked me how to get more heat out
of the Vanagon and i detailed this. he just shook his head.
Alternatively, you can elect to do the whole system. However, be
forwarned that many cleaners foam and can create a headache for you
as the radiator air-locks with foam. yes, this is the voice of
experience. it is also difficult to flush out the cleaners from
the wasserboxer's 19+ liter system. installation of a flushing T in
the heater loop would facillitate this but some people are
experiencing failure of these T's. i think i will install one
anyway.
Chemicals. I have read an article that discouraged the use of Oxalic
acid, this is the cleaner in the powdered Prestone 2-step cans. I
used this before i read the article and it did no harm. i will check
that article again to see what the specific problem was with it. but
i seem to recall that it wasn't effective on solder bloom.
actually, since the vanagon uses an aluminum based cores,
solder bloom is not a factor in the radiator or heater circuits.
essentially, we want a degreaser/emulsifier/cleaner. i haven't yet
decided what product to use. the cans are not very descriptive as to
their active ingredients.
One thought. some cleaners are organic based. maybe, just maybe one
of these would react with the neoprene head seal, swelling it and
stopping our leaks. huh? ya think? not likely. might try one this
time though.
-dan