MOTOR GP-PISTON 2862474 - Caterpillar

CONFIDENTIAL
TECHNICAL INFORMATION BULLETIN January 16th, 2002
ARTICULATED TRUCKS D400EII Ejector
Component Code(s) 5305SUBJECT: EXTERNAL EJECTOR CYLINDER LEAKAGE
PROBLEM:
The current D400E II Ejector Cylinder is a unique four stage telescopic unit, which extends 4600 mm at full stroke, with individual stages 1474 mm long and diameters that range from 128 mm to 212 mm. These relatively large cross sections and lengths of stroke inherently carry more oil on their surfaces during operation.
As a result, in normal operation there will be evidence of oil remaining around the wiper seals on each stage of a retracted cylinder. Thus, an ejector cylinder will normally have some hydraulic oil present at the wiper seals and would be classified as seeping. Use the information that is provided below to classify the level of oil that is evident from the ejector cylinder.
The purpose of this TIB is to provide:
An understanding that slight leakage from the wiper seals is NORMAL for this cylinder.
Guidance on how to classify the amount of leakage.
Guidance on whether the external leakage rate will be improved by repair.
SOLUTION:
Use the following information in order to classify and leakage of oil that is evident from the ejector cylinder.
Classification of Oil Evidient from The Wiper Seals of the Ejector Cylinder
Classification Description Dust Accumulation
Moist Oil film does not result in forming oil droplets Moist thin layer of dust that is less than 3mm thick
Seep Oil film develops a visible droplet Wet layer of dust that is thicker than 3mm
Weep Reccuring oil forms rdroplets that are seen along the cylinder length Oil washes through the accumulated dust
Leak Recurring oil creates a visible stream of oil droplets Oil drips from the cylinder onto the surface of the hitch or the bed of the truckLeakage that is classified as "moist" is normal.
Leakage that is classified as "seep" is normal for a used cylinder. Repair may provide improvement but is not necessary.
Leakage that is classified as "weep" or "leak" is not normal. Repair is necessary.
Hydraulic oil that is weeping or leaking from the cylinder sections during operation (1 drip very 30 seconds or less, with the cylinder fully retracted and the engine running at low idle) is not normal. An ejector cylinder with external leakage at the wiper seals should be monitored in the context of the above classification and should be reported by NACD dealers to :
Jim Coffey, Waco Product Support, ph# 254-420-5532
Bob Murray, Joliet Service Engineering, ph# 815-729-5432
Dealers outside of NACD should report the problem to
Bob Lynn, Peterlee Product Support, ph# 0044-191-569-2611
Dealer with specific questions on ejector cylinder tooling and disassembly and assembly procedures should continue to contact CSTG?s Ron Mahrt on ph# 309-675-8633
COPYRIGHT 2001 CATERPILLAR
ALL RIGHTS RESERVED