The Pilot Valve May Generate Noise And Not Operate Smoothly On Certain Excavators [TIBU4516]

HYDRAULIC SYSTEM

VALVE GP-PILOT

The Pilot Valve May Generate Noise And Not Operate Smoothly On Certain Excavators

CONFIDENTIAL TIBU4516-00

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TECHNICAL INFORMATION BULLETIN	MAY 04, 2005
EXCAVATORS	307C (BNE, BAJ, BCM), 308C CR (CPE), 308C SR (CRW, KCX), 311C U (CKE, CLK), 312C (CBA, CAE, BNN, DBN, FDS), 312C L (BWH, CBT), 313C CR (HGF), 313C SR (WSA), 314C CR (KJA, KHB), 314C LCR (PCA), 315C (CFB, AKE, BTL, CFL), 315C L (CJC, ANF, CFT), 318C (FAA, GPA, BTG, DAH, CWP, AWS, MDY), 319C LN (KGL), 320C (FBA, GHA, MAA, BCB, MAB, AMC, BDC, FBC, CCD, BEF, DBG, AKH, BCN, BPR, RAW), 320C L (EGA, GAA, GLA, PAA, ANB, BDB, PAB, BBC, GAC, HBC, BDE, ALF, JPL, SBN, BER, BRX), 320C S (BBL, EGL), 320C U (APA, FBB, MAC, CLM), 320C LN (BEA, JTG, AXK), 320C LU (GAB, ALX, CLZ), 320C LRR (PAC, GAD), 320C FMST (BKK, TBR, 320C FMHW (BGB, SAH), 321C CR (DAX), 321C LCR (KBB, MCF), 322C (DAA, HBG, BFN, BLP, BNY, ADX), 322C L (FED, BTE, KCF, BKJ, HEK, BKM, BGR, MAR, BFX, BMX), 322C LN (BFK, EMR), 322C LGP (BYL, SLX), 322C FMST (BPH, M2H), 322C FMHW (CAM, C3R, LAR, CBY), 325C (BLA, JLD, DTF, AMH, BKH, BKW), 325C L (CRB, JLC, BTD, BFE, BMM, BKT, BLX), 325C LN (CSJ), 325C MH (S2C), 325C FMST (G1L), 325C FMHW (M2K, S3M, Y4P), 330C (MCA, JAB, NAB, GAG, JCD, BTM), 330C L (CYA, HAA, KDD, JNK, RBH, MKM, SCN, CAP, GKX, DKY), 330C LN (CGZ), 330C MH (D3C), 330C FMST (B3M), 330C FMHW (B1K, B2L, B4N) EXCAVATORS
	Component Code(s) 5059

SUBJECT: THE PILOT VALVE MAY GENERATE NOISE AND NOT OPERATE
SMOOTHLY ON CERTAIN EXCAVATORS

PROBLEM:

The pilot valve may generate undesirable noise during operation of the front implements. Smooth operation of the front implements may also be difficult to obtain. These problems are created by increased hydraulic system backpressure flowing through the small pressure opening area in the pilot valve.

SOLUTION:

If the pilot valve generates noise and controllability is undesirable, replace the former 165-9569 Pilot Valve with a new 206-3305 Pilot Valve. The new pilot valve has increased the pressure opening area in the valve. The increased pressure opening area eliminates the noise and improves controllability. The location of the increased area in the pilot valve is shown in Illustration 1.