Date: Thu, 21 Mar 2002 14:54:59 -0400
Reply-To: Malcolm Stebbins <Malcolm.Stebbins@MSVU.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Malcolm Stebbins <Malcolm.Stebbins@MSVU.CA>
Subject: Re: self-bleeding coolant? LONG replay
In-Reply-To: <F103DBHy3SpwBGpEI2r0000414d@hotmail.com>
Content-type: text/plain; charset=US-ASCII
On 20 Mar 2002 at 17:51, Dart 330 wrote:
> How does one bleed the van without raising the front?
I have done this several times:
I flush - then drain the coolant system. To drain, I disconnect many of the hoses. (I
have even been known to BLOW HARD on some of the hoses to force any
remaining liquid up and over any high spots to better drain the system).
I then re-connect all of the coolant hoses, open the front and rear heater levers,
remove! the front radiator bleeder bolt, open the thermostat bleeder screw-thingy on
top of the thermostat housing (to let the air out for the next step).
I look up the coolant capacity of the vanagon in the Bentley manual and divide that
number by 2 and use this quantity of undiluted coolant for the next step. I begin
adding 100% coolant into the rear-left coolant reservoir and maybe through any
convenient hoses that will fill the hoses going to the front of the van. I fill as much as
I can and maybe blow hard again to force the coolant up and over any high spots
(this is an oral adaptation/modification of the bicycle pump trick).
Now I have my wife/son/friend watch the front radiator bleed hole, and I watch the
rear-left coolant expansion tank, and I start the van. I keep adding 100% coolant till I
run out (of the numbers of litres that I know make up a 50/50 mix). After I run out of
coolant, I switch to adding water (take your pick between distilled and tap water).
The thermostat bleeder screw-thingy will start to squirt soon and when it does, I
close it.
When the coolant starts squirting out of the front radiator bleeder hole, (I may need to
wait for the van to warm up and I may have to rev the van a bit for this step (that's
where the 2000 rpms comes in that we hear about)) I turn off the engine and screw in
the front radiator bleeder bold - hand tight!
All the while, I keep an eye on the coolant level in the rear-left expansion tank,
adding coolant (or then water) as needed to keep it full and feeding the water pump -
don't want the water/coolant pump to go dry with the engine running. (Some people
talk of an air locked water/coolant pump, but I have never had this problem).
If things are going smoothly, the system will stop taking water in the rear-left coolant
expansion tank. I then loosen the front radiator bleed bolt and let the air out while
reving the engine, then when coolant comes out, I hand tighten the front radiator
bleeder bolt. Now I repeat the sequence: rev, bleed, add coolant, rev, bleed, add
coolant, rev, bleed, add coolant, for a few minutes.
By now the engine as been running for 10 or 15 minutes and the temp gauge needle
on the dash has started to rise and then I know that the thermostat has opened. This
helps move more coolant and air around the system to either the front radiator or to
the rear-left expansion tank. Repeat the front radiator bleed.
Pretty soon things calm down and I get no more air out of the front radiator and I can
add no more water (water by now) to the rear-left coolant expansion tank. I tighten
the front radiator bleeder bolt. Put the cap on the rear-left coolant expansion tank
and connect the hose to the rear-right overflow tank (behind the licence plate). I may
try and bleed the rear heater with the bleeder screw that's on top of the on-off valve.
Now I am pretty sure that MOST of the system is filled with coolant and I have MOST
of the air out of the system. I may still have some air in the system, but I can drive
the van.
I fill the rear-RIGHT overflow tank with a 50/50 coolant mix up to about 1/2 to 2/3 of
the tank. I can now either drive the van or I can turn it off, and when the coolant
does (eventually) cool down, coolant will be sucked from the right overflow tank into
the left expansion tank (this is my vocabulary anyway).
Now I can drive the van and I do. I leave the front grill off so that I can quickly and
easily bleed the front radiator about every 100 kms (when the engine is warmed up
and at 2000 rpms). The act of driving the van atomizes any air into small bubbles
and passes it along (usually) to the front radiator or the rear-left coolant expansion
tank. After about 3 or 4 times (300 to 400 kms) of bleeding the front radiator, the
thermostat housing pee hole, and filling the rear left expansion & rear right overflow
tanks, I get no more air out of the system, I am pretty sure that nearly all of the air is
out of the system.
I should say that I have a Canadian spec 1991 syncro (westy) which has (after the
PO's engine-box fire) a bastardized coolant hose system (and a carb) so I may have
easier access to some of the hoses than you FI guys.
So that's how I bleed my van's coolant system without raising the front end. Of
course it helps if you live in a hilly part of the country, that way driving up a steep hill
will help move the air around.
On this list I have read of several methods of bleeding the coolant system and I only
put this procedure forward as 'a' method and not as 'the' method and maybe it should
only be used in emergencies or when driving through the Egyptian desert and your
coolant system blows and you need to get home ASAP.
