10
SECTION 00 -- GENERAL
604.13.542.01 -- 03 -- 2006
MAINTENANCE TECHNIQUES
GENERAL NOTICES
Clean the outside of all the components prior to per-
forminganytypeofrepair.Dirt andabrasivedustcan
reduce the efficient life expectancy of a component
and result in expensive repairs.
The time spent in preparing and cleaning working
surfaces is giving results, making work easier and
safer, and the components overhauled will be more
reliable and operate better.
Use cleaningfluidsproven tobe safe.Sometypesof
fluidcancauseseriousproblemstoO--Rings andirri-
tate the skin. It is necessary to check that the sol-
vents are suitable to clean the components and that
of they are free of risks for the health of workers.
ReplaceO--Rings,sealingringsandsealseverytime
they aremoved. Neveruseold O--Rings or sealsand
new ones together, independently from their condi-
tions. Always lubricate new O--Rings and seals with
hydraulic oil before installing them.
When replacing components, alwaysuse thetooling
required by this type of work.
HOSES AND STEEL PIPES
Alwaysreplacehosesandsteel pipeswhenthetaper
end or connections are damaged.
When a new hose is installed, connect it without
tighteningtheends and make surethat it is routedin
the correct manner, before tightening the ends. Fix-
turesmust be tightened justenough tohold thehose
without squeezing it, avoiding rubbing as well.
After replacinga hose of moving components, make
sure that the hose is not disturbed by the movement
of the component in any position.
Make sure that all hoses installed are not choked or
bent.
If hoseconnectionsaredamaged,dented,chokedor
leaking, decrease the flow of oil and the productivity
of the relevant actuators. Connections showing
signs of displacement from their original pre--
pressed position must be considered as already
broken, sincetheyare going to fail or separatesoon.
A hose with a ragged outer sleeve allows water to
penetrate. Thus, hidden corrosion of the reinforcing
wire will develop along the entire length of the hose,
with the subsequent failure of the hose itself.
If ahoseswells, thisindicatesthatthereisaninternal
leakage due to a structural failure. This condition
deteriorates very quickly and causes the failure of
the hose.
Clogged, squeezed, excessively tensioned or
deformed hoses are generally easily subject to flow
reduction, decrement of theoperationalspeed of the
fluid and the final failure of the hose.
Loose hoses move freely and must be prevented
from touching each other and nearby surfaces. This
causes a rubbing action shortening the useful life of
the hose.
CONNECTIONS WITH FRONT SEALING
O--RINGS
When repairing connections with front sealing
O--Rings, please comply with the following pro-
cedures.
W ARNING: NEVER DISCONNECT, NOR
TIGHTEN A HOSE OR A STEEL PIPE UNDER
PRESSURE. IFIN DOUBT, MOVE THECONTROL
LVERS SEVERAL TIMES WITH THE ENGINE
INOPERATIVE BEFORE DISCONNECTING A
HOSE OR A STEEL PIPE.
1. Loosen the connections and separate the hose
or steel pipe, then remove and eliminate the
O--Rings from the connection.
2. Dip a new O--Ring in clean, hydraulic oil before
installing it. Install the new O--Ring in the con-
nection and, if necessary, hold it in its position
with vaseline.
3. Install a new hoseor steelpipe and tightenman-
ually the connection holding, at the same time,
the pipe still to prevent it from turning.
4. Use two wrenches to tighten the connection to
the torque prescribed for its size. Please referto
the table to follow for the tightening torques.
NOTE: to ensure that a joint does not leak, it is
important that the connections are neither
excessively tightened nor too little.
To Next Page
Loading...
Need help?
General
