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Vacuum caster is giving me trouble

My vacuum caster -Pro Craft model #21.819 is giving me trouble.
The motor works, but it wont produce a vacuum. Oil has been
changed. It’s at the proper level. Help! I don’t know what to do.


Open the machine and make sure all the tubes are tight, not pinched
ore deteriorated.

Fr. Alexis

vacuum caster -Pro Craft  model #21.819...The motor works, but it
wont produce a vacuum. 

Is the problem actually at the motor? Have you examined the hoses
to make certain they’re clear? Investment can build up. Do you have
any filters in-line that could be replaced?

Dana Carlson

Remove the vacuum hose at the vacuum pump, if you can, and check the
vacuum at the pump inlet. If you have a vacuum there you have a
clogged hose somewhere or a crimped hose. You need a filter in the
vacuum line and a way to trap any silver or investment that might
break through the mold. This is usually a container that has both
an inlet and an outlet hose connection at the top. The hoses are not
connected to each other. If silver or investment gets sucked into
the container it will settle to the bottom and not be pulled out of
the container into the line to the pump.

If there is no vacuum at the pump inlet you have a faulty pump. It
will need to go to a vacuum repair shop.

I had the same problem with my vacuum pump during a critical casting
cycle. The motor ran but no vacuum at the pump inlet. I took the
malfunctioning pump in to our jewelry supply house and bought
another one. I had too much time in the original molds and could
not afford to lose them. The vacuum pump had a broken part. It
works fine now. The only problem is I now have an expensive backup

I hope you fine the problem is clogged lines.

Lee Epperson

had a simular problem…for years… finaly it broke and I found out
the problem… there was a union made of a plastic material that
joined the pump to the motor… it was sliping somtimes… couldnt
see the problem because the entire unit was in a metal box!! Jim

Hi Jim (Chambers),

I had that exact same problem. A molded plastic piece which is
notched to fit the gears, cracked. This piece goes between the motor
gear and the pump gear. Obviously, if this piece gets disconnected
or slips, the motor will not turn the pump to create the vacuum. I
was able to order a replacement part, but in the mean time, I took
black tape and wrapped it real good around the broken plastic piece
and this held me over until the new part arrived. Now my vacuum
casting machine is as good as new.

Glenn Block
Shardan Jewelry

 My vacuum caster -Pro Craft  model #21.819 is giving me trouble.
The motor works, but it wont produce a vacuum.  Oil has been
changed. It's at the proper level.  Help!  I don't know what to do.

Well!.. went through that for 5 years…never found the problem
…TILL!!.. it finally broke!!! I tried every possibility known to
man and talked to some beast as well, they didn’t now either!!

Went it broke!!! ‘‘A’’(maybe not the right one) problem was the
coupling between the pump and motor. The coupling was made of a
bakelite or hard rubber and fractured (I believe that it had been
sliping and therefore a vac was only established whenever the ‘moon
was in acquarius’!)


It could be the silicone pad isn’t sealing,


It could be your investment top/bottom is too thick or too thin in
the flask,


There isn’t enough room in the cylinder to establish a vacuum in the
cylinder (need 1/4 inch at the top,


You have burned rings in the silicone pad such that a vac can not be
establish… Pad temp by specification should not exceed 900F,and on
and on, and on!!!

But, my machine was several years old when this happened.

Switched to Centrifugal… am very, very happy that it broke …
really don’t have time to mess with the many, many problems associated
with vac casting. Sorry, really don’t wish to re-start the ‘vac vs.
centrifugal’ again! Vac is the way to go for large castings or large


Mine is broken as well (vacume caster). Just replaced the three way
valve. Still doesn’t work. I’m so frustrated with it.

You might take the pump back to the supplier or find a shop that
works on compressors and vacuum pumps. If the motor is running and
the connection between the motor and the pump is not slipping and
there is no vacuum at the pump inlet the chances are very good there
is something wrong inside the pump.

Lee Epperson

Vacuum casting machines are sometimes trouble. For those having
trouble with their machine, call us. We often can help you fix it
over the phone. We will be back in the repair shop Tuesday.

Until then… Motor to pump coupeling problems? This part is
available at Grainger, located in most major cities. Valve bad? you
must use the replacement made for vacuum casting machines, not
standard ones that look like it. Most places that sell the casting
machines have the replacement valves. Correct valve and it still
doesn’t work? The valve handle can be removed and reinstalled 180
(up side down) and then turned to the correct position. Hope this

The jewelry Equipment Dr.

I would always check with Jon cranor on the vac-casters … As lee
stated something in the pump or as simple as the casting table to be

Andy “The Tool Guy” Kroungold
Sales/ Tools and Technical
Stuller Inc.
337-262-7700 ext. 4194
337-262-7791 fax