YORK INTERNATIONAL
6
SECTION 2
COMPRESSOR SERVICE
The compressor is the heart of the chiller and every
effort should be made to maintain and keep it operating
at peak efficiency. Being a precision-built machine, it is
important to check the lubrication system for cleanli-
ness by changing the oil filter as mentioned under Pre-
ventative Maintenance in the Operating Instruction.
The compressor should not be disassembled for inspec-
tion purposes only. However, if the compressor fails to
function as outlined in the OPERATING MANUAL, it
may be necessary to do so. Individual parts are avail-
able for replacement as described in the following com-
pressor servicing section.
SERVICE GUIDELINES
The overhaul and replacement of parts of these com-
pressors, like any other mechanical operation on ma-
chinery, is best accomplished by experienced service
personnel using tools and measuring instruments to ac-
complish accuracy in their work.
There are a number of good practices that should be
followed in disassembly and reassembly of the com-
pressor; some of these are listed below.
Do Not Mix Parts – Keep parts in some general order
when removing them from the compressor. It is sug-
gested that parts be laid out to follow exploded views as
shown in the many illustrations outlining the disassem-
bly and assembly of the various parts.
Do Not Mix Cap Screws and Washers – Cap screws
are suited to the location in which they are used. Too
long or too short a cap screw can result in leakage
and/or interference with some interior parts. Wash-
ers have been selected for specific screws, etc. It is
very important to use correct washers or
lockwashers. The parts list and figures in this instruc-
tion show the correct length and size of screws and
washers. See the Renewal Parts Manual to order
the correct part numbers.
Inspect As Compressor is Disassembled – If pos-
sible, it is desirable to record shaft and impeller runouts
and thrust clearances before disassembly. Once com-
pressor parts have been disassembled and cleaned, many
valuable indications of the compressor condition are lost.
Materials found in oil or on burned surfaces can often
give an indication as to why a part or parts have failed.
Protect Parts and Surfaces – Do not pile or throw
parts indiscriminately. Oil surfaces likely to rust. Tape
surfaces subjected to scratching or nicking during re-
pair operations. Plug off any passages likely to accu-
mulate dust or abrasives. Do not tape the seals.
Clean Thoroughly – No compressor is completely over-
hauled if it is not cleaned internally to “new part” condi-
tion. Dirty parts can not be inspected or fitted and will
cause excessive wear when compressor is in operation.
CLEANING AND CHECKING WEARING PARTS
Before reassembling the compressor, all parts should
be thoroughly checked for excessive wear.
Worn parts should be replaced with new and each new
part should be thoroughly examined for shipping damage.
While the rotor support is open, carefully clean the inte-
rior, using an approved safety solvent and a lint free cloth.
Clean and check all oil passageways and all tubing.
Before assembling parts, all friction surfaces should be
lightly coated with a molybdenum disulfide lubricant
such as “Molykote” or “Molkolube” and oil. Be sure to
use new YORK refrigerant oil.
“Molkolube” is available from:
Dow Corning Corporation
Dept. A0021
P.O. Box 1767
Midland, Michigan
It is also available from YORK (Part No. 364-21508) in
2 oz. cans.
When reassembling parts, each part should be carefully
checked for signs of uneven wear, keeping in mind that
a nicely polished surface is not an indication of exces-
sive wear. Sudden, excessive wear on any part of the
compressor is not normal but is usually caused by some
other condition which must be determined and corrected
to assure long periods of trouble-free operation.
Bearings and seals may be reused if their rubbing sur-
faces and matching surfaces of their corresponding ro-
tating parts are nicely polished with no sign of uneven
wear or gouging.
The impeller should be checked around its outside cir-
cumference for evidence of rubbing. If this condition is
Compressor Service
