Air Step problem - will not completely extend without 'help'

[Gregory OConnor]

I had the same prob as a symtom to a bad seal in the ram. When
I would tug the step fully open the air hissing would stop. (My
94pt40 has a non spring ram with two air ports) If you remove the ram
and blow air in, to push the stroke out , the air should stop blowing
out the other port when the stroke bottoms out. if the air continues
to blow out the other port the seal is bad in the ram. You may be
able to remove both airlines to the ram and test it without removing
the ram first. I tried to split the ram open to replace the seal but
the Clippar ram used on my bus could not be serviced.

The step cams open and does not require pressure to hold it open.
The ram is duel acting (pushForce pullForce). To open; one valve
pushes air into the ram thus pushing the stroke out. The other valve
escapes the air as exhaust. The only exhaust on a new ram is the
content of the unopen ram. what you hear is air passing the plundger
seal in the bad ram and adding to the exhaust. The movement of the
step hindge just before the step cams to an open rest require the
most ram force. Your ram may have been wearing out over time and now
it has too much blowby to pass the cam and lock the step out.
Clippard.com has an online store and I think the exact replacement
for my bus was around $200.????? The last two numbers on the Bad ram
were SP or somthing like that which turned out to be special order
and not important. I upgraded the seal within the ram for $35.00???
to a "V" which stands for the name of the rubber compound used to
make the seal.

The fix is easy but take care not to lose a finger in a surprise step
movement. I think moisture in the ram freezeup and cut the plundger
seal and or dirt gets in through the wiper seal at the strope end?????

GregoryO'Connor
94PTRomolandCa


Gregory O'Connor
94PT40 Romoland California
--- In WanderlodgeForum@yahoogroups.com, "rogerwwebb"
wrote:
>
> My air step is hanging up during extension (opening) and is not
fully
> extending without 'help' from my foot, shaking the step a bit. No
> problem with retraction (closing).
>
> Lubricating all pivot points did not help.
>
> Air expels during the opening and closing process, as is normal.
Once
> the step is locked into place, either open or closed, it stops.
>
> However, when the step hangs up (partially open) air continues to
expel
> from what I believe to be the step solenoid valve. In particular
the
> escaping air is coming from one of the two 'spark plug shaped'
devices
> on the bottom of the valve.
>
> Advice appreciated ... and if someone could give me the proper name
of
> the 'spark plug shaped' devices, that too, would be appreciated.
>
> Roger Webb
> 91 WL
> Cedar Rapids, IA
>