Supplemental Vacuum Pump

[larry & kaye kepple]

[Admin note - Bounced due to bad "From" header. Patrick]

I recently added a new vac. pump for backup for braking in case of
engine failure. I felt real good about it at first. But then I got to
wondering what happens if the vac. pump fails such that I lose vac. to
brake booster when engine is still running. Aren't these pumps simply a
diaphram pump with check valves on each side. If that's the case then
wouldn't the brake booster lose most or all vacuum if the diaphram
ruptures. Wouldn't a diaphram rupture result in a large vac. leak at
this location? Hopefully there is something that prevents this. Larry

 

[patrick flowers]

>
> Larry - the diaphragm is sealed in a metal chamber. If it failed the pump
> would have an internal leak at the diaphram and would not work, but the
> engine would still pull a vacuum through the pump from the booster to the
> engine. This is one reason that the vacuum pump should be put in series with
> the engine vacuum line.

Emery,

Just curious, how would you know that the pump had failed before you
need it? Could you turn the ignition switch to "on" and listen for it
to pump up and shut off before starting? I installed a switch on my air
compressor just so I could hear something besides it whenever I start
the coach.

I don't have one of these(yet!).
Patrick
- --
Patrick Flowers
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