Hissing of air in front

[Gregory OConnor]

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.
> >
>