Hissing of air in front

[Bob Lawrence]

Thanks Greg,
The prices you quoted are a LOT more reasonable than the 4k HWH wants
to retool.
I'll pass on yours and Ralph recommendations.
Thanks again.
Bob Lawrence
84 PT36
Tacoma, Wa.
--- In WanderlodgeForum@yahoogroups.com, "Gregory OConnor"
wrote:
>
> Bob, The 'spring brake' 'parking brake' that the valve control
feed
> a blatter that requires air to pull the brake shoe off the drum.
> park brake is passivly on and needs dynamic attention (compressed
air)
> to release. if there is a hissing noise (like KenS TexasMike and
> Jim's post)it could be that the blatter is leaking and the air to
> release is constantly being pushed through the valve to try and
> maintain the release of the brake?????? Often when a brake release
> line or blatter is leaking you can hear air rush through this
valve.
> the other possibility is ;the port in the valve that exhaust the
air
> that was trapped holding the brake shoe off the drum is stuck open
> with debris. You may want to check that the air dryer is working as
> that could cause probs like stuck valves and ports.
>
> I would bench the hwh pump, and send it off to a good hydryloic
shop.
> it is nothing more than a electric motor driven hydrolic pump much
> like the units that power lift gates on delivery trucks. Low
battery
> use of any electric pump will eat up the motor ( bad grounds and
> undersized wire will do the same damage). when the motor gets
> compramised the failure is expotential and the battery requirement
to
> run gets larger. the pump does not get hurt by a weak battery and
or
> screwed up motor. I bet the e-motor is less than $300. to rebuild
and
> the pump woud be less than $600. ( no need to rebuild unless the
pump
> was the cause of e motor failure or slow run).
>
> GregoryO'Connor
> 94ptRomolandCa
>
>
> --- In WanderlodgeForum@yahoogroups.com, "Stephen Birtles"
> wrote:
> >
> > Replace the valve about twenty dollars
> > Cant help with the pump
> > Stephen 77fc35
> >
> >
> >
> > --- In WanderlodgeForum@yahoogroups.com, "Bob Lawrence"
> > wrote:
> > >
> > > Hi group,
> > > One of our PNW bird guys has a air hissing problem. It seems
that
> when
> > > he pushes in the emergency valve, a black hose on the drivers
> side that
> > > hangs down hisses air. When the valve is pulled, the air leak
> stops.
> > > What can I tell him that might be the cause?
> > > He has an 87 PT40.
> > > Also he has been told his HWH pump is shot and will cost approx
> 4k to
> > > make a new one (per his conversation with HWH). Any other
source
> for
> > > this? He wants to get new if possible.
> > > Thanks for your help.
> > >
> > > Bob Lawrence
> > > 84 PT36
> > > Tacoma, Wa.
> > >
> >
>