Zuma – Adjusting & Handling (N016568)
December 4, 2001
Page 1
Zuma Brewer Adjusting and Handling Procedures
For the past few weeks, we have been analyzing the Zuma brewers that have been returned to us for
repair. The majority of these brewer were received with damaged bearings and vertical rod housings. Our
analysis indicates that in most cases, too much tension was placed on the brew chambers. When the
chambers are overtightened, there is too much pressure placed on both the bearings and the vertical rod
housings, resulting in damage to these components.
This document was created to guide you through the adjusting and handling procedures that are essential
for keeping the Zuma brewers operating efficiently. Following these procedures will reduce the risk of
damage to the brewers.
It is imperative that this information be shared with all your service staff.
Please post this document in an area that is accessible to everyone.
Brew Chamber Tension Adjustment
•
When adjusting the tension on the brewer, add full shims (K011950) or half shims (K011191
between the T-bar and the H-frame, as illustrated below. These shims must be added one at a
time.
Do not add several shims at once as the tension may be increased too much.
In most cases, this simple procedure is enough to stop the leaking. However, if the brewer still
leaks at this point, repeat the procedure and add one more shim (
start with one half shim
– if
that’s not enough, remove the half shim and add one full shim).
•
Turning the T-bar should be avoided and should only be done as a last resort.
If the brewer
tension is still too loose after installing two
full
shims, remove the two shims and
only once they
are removed
should you turn the T-bar
one
rotation clockwise.
•
If the wiper is hitting the coffee paddy as it moves towards the left, this indicates that the brew
chamber is not rising high enough. Either something is interfering with the upward motion of the
chamber, or the chamber tension is too tight.
•
If the tension is adjusted properly and the brewer is flooding,
do not tighten the brew chamber
even more.
Increase the bottom pause, lower the water temperature or replace the filter screen. If
the problem persists, check the brewer to make certain there is no loss of vacuum, usually caused
by a cracked brew chamber or cylinder, a worn or scored cylinder, or a worn Teflon seal.
