Losing coolant

[Gregory OConnor]

There are two springs in the cap a puke and a suck. when the rad
fluid cools it creates a vacumn and sucks the puked fluid out of
the p tank and back into the system. Could be the return path
(suck) is screwed and letting air enter on the path of least r
theory some place. then when it pukes again the tank is overfilled.
I think the suck is more of a check valve than a presssure thing????

I see your point about boil and 250 degree but I bet lots'a water up
against the block gets close to 250 and sees greater expansion. we
read 195 relative temp at a place remote to the heated area being
cooled.
I wonder if seven is the way to go but the puke tank is not sized
properly considering the large volumn of fluid to displace in the
Wanderlodge application.

One of those places where fluid level wont prove a shutdown. if you
are running the bus hot and pucking fluid in the tank that holds the
level sender. may have been one of Rons lost chances for early shut
down.

Greg94ptCa
--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> The parts book that came with this coach calls for a 7 lb. I have
no idea when this one was changed to a 13 lb.
>
> There is a thread back in March of 2007 starting with post 20947
where Curt Sprenger said:
>
> "Coolant Pressure Control Cap...the 92 series manual recommends all
> series 92 on-highway vehicle engines use a minimum 9 psi control
cap.
> My radiator cap is a 7 psi. Is this a Bluebird change? What are
others
> using? Should I be concerned? The engine temperature runs at about
185
> to 195."
>
> That thread ended up being more about alarmstats, misters, etc.
but besides you (Leroy) mentioning that you had a 13, Pete posted in
that thread that the shop that did his radiator replaced with a 15.
>
> I'm going to guess that a higher one gets used precisely because
the 7 lb, as it loses strength, tends to let more slop out.
>
> If you think about it, a 7 lb with a boiling point somewhere above
230 degrees is into temperatures where the engine would be in real
trouble anyway. Increasing the cap pressure to 13 takes boiling to
250, but does that really matter?
>
> I'm thinking I will go looking for a new cap tomorrow as an
easy "maybe fix", and I will look for one around the same 13 lbs.
>
> On 10/23/2008 at 6:17 PM Leroy Eckert wrote:
>
> >I have a 13lb cap also and it is old. Same year.
> >Leroy Eckert
> >1990 WB-40 Smoke N Mirrors
> >Dahlonega, GA
> >Royale Conversion
> >
> >--- On Thu, 10/23/08, Joyce and Richard Hayden
wrote:
> >From: Joyce and Richard Hayden
> >Subject: Re: [WanderlodgeForum] Losing coolant
> >To: WanderlodgeForum@yahoogroups.com
> >Date: Thursday, October 23, 2008, 8:32 PM
> >
> >Don, I would wonder why someone has put a 13 # cap on your
cooling
> >system. The standard for these engines have been 7#. I haven't
heard
> >of very many with anything above that.
> >
> >Dick Hayden - '87 PT 38 - Lake Stevens, WA - still in Medford, OR
but on
> >the road again tomorrow after the tranny is fixed.
>