Date: Thu, 18 Feb 2016 17:12:08 +0000
Reply-To: Michael McSwain <michaelmcswain@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Michael McSwain <michaelmcswain@GMAIL.COM>
Subject: Re: Expansion tank under pressure when cold?
In-Reply-To: <BAY405-EAS163B874574FBB5EE087B4F7A0AF0@phx.gbl>
Content-Type: text/plain; charset=UTF-8
Well I was able to open the expansion tank this morning without overflow.
My parking spot is on an ever so slight incline and I guess it was enough
that I needed to back it in to put the back end on the high side.
I tried pumping about 8psi into the expansion tank and immediately found
some bubbles coming out of the top hose of the H pipe. Put on a new hose
clamp and snugged it up and that seems ok now. Also found the rear heater
core valve to be leaking. Put a Home Depot ball valve in just before the
old valve and left it closed. As I'm writing this however I'm thinking that
the old valve still needs to be replaced. Would the return side of the
rear heater core still have pressure with the valve closed or would there
be suction? Either way it will either be pushing coolant out or sucking air
in. I guess another ball valve on the return line would work.
Still smell a little antifreeze in the cab though so I'm guessing I have a
problem with or near the front heater core.
Can't tell you how much I appreciate this community. I would never have
sold my Canadian model 85 Wolfsburg Westy in 1999 if I had access to so
many knowledgeable folks willing to share their experience.
On Thu, Feb 18, 2016, 11:12 AM Dennis Haynes <d23haynes57@hotmail.com>
wrote:
> Using the emissions sniffer or even test solutions to look for
> hydrocarbons in the coolant is really limited. The leak has to be so bad
> that you also have a combustion failure. No combustion issues you should
> have no unburned hydro carbons.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Stuart MacMillan
> Sent: Wednesday, February 17, 2016 2:03 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Expansion tank under pressure when cold?
>
> Bentley says apply 14.5 psi for leak testing (p. 19.17), and cap opens at
> 13 to 17 psi (p. 19.18). I use my Motive Products pressure brake bleeder,
> but anything with a gauge will work, just connect a hose to the cap. Put a
> large piece of clean cardboard under the engine and look for drips
> immediately as well as overnight (system should hold pressure for several
> hours). If you are smelling coolant, it could be the rubber head gaskets
> leaking, but that would not lead to a pressurized tank.
>
> An emissions sniffer can detect combustion gasses in the cooling system,
> but for that to work there has to be considerable air space in the pressure
> tank, and the probe inserted quickly after opening the cap. Not so easy,
> and the shop is not going to want to contaminate their probe with coolant.
>
> Also, it's worth taking the cover off the rear heater and pulling out the
> core. I'll bet it's leaking if it's original.
>
> You’ve got air in the system, hopefully it's not from combustion gasses.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Michael McSwain
> Sent: Wednesday, February 17, 2016 10:14 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Expansion tank under pressure when cold?
>
> Any easy way to test for combustion gasses getting into the coolant?
>
> Loose or cracked heads would produce a leak or weeping from the head area
> I assume?
>
> Radiator should be easy enough to check for leaks, but heater core not so
> much.
>
> I've tried taking the expansion tank cap off after letting the van sit
> overnight and it still overflows when removed. Where I park it is slightly
> inclined with the front end up, but not much. I'll try parking it front
> down tonight and try removing it again tomorrow morning.
>
> Is applying 10 or so psi of pressure to the expansion tank and looking for
> pressure drop and leaks a bad idea?
>
>
>
> On Wed, Feb 17, 2016 at 1:01 PM, Dan N <dn92610@gmail.com> wrote:
>
> > I think it depends on how long you let the engine rest after you shut
> > it down. There always some residual pressure in the cooling system and
> > it will come near zero if you wait long enough... I let it sit
> > overnight. My mechanic revs the engine up to bring the level down, add
> > the coolant and put on the cap presto..
> >
>
>
>
> --
> m.
>
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