VALVE GP-PILOT 1232147 - Caterpillar

Introduction
For Specifications with illustrations, make reference to the SPECIFICATIONS FOR 613 WHEEL TRACTOR POWER TRAIN, Form No. SENR7910. If the Specifications in Form SENR7910 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.Power Train
Problem Solving
This is intended as a reference for locating and correcting problems that may occur in the power train. In the event further investigation is necessary, use of the 7S8875 or 8M2736 Hydraulic Test Box will be helpful. Pressure tap locations and testing and adjusting procedures are defined in TORQUE CONVERTER, TRANSMISSION AND HYDRAULIC CONTROLS - TESTING AND ADJUSTING.In all instances, visual checks of the machine should be made first and then operational checks before proceeding to instrumentation tests.Visual Checks
1. Check the oil level in the transmission.2. Examine all external oil lines, hoses and connections for leaks and damage. Look on the ground beneath the machine for evidence of leaks and locate their source.3. Move the speed selector lever to REVERSE position and all FORWARD positions. The detents should be felt in each position.4. Drain the transmission lubrication oil filter housing, remove and check the filter element for foreign material. Also, check the magnetic strainer. a. Bronze-colored particles would indicate a clutch failure.b. Bright steel particles in the filter indicate a pump failure.c. Aluminum particles indicate a torque converter failure.d. Rubber particles indicate a blown seal or ruptured hose.If metal or rubber particles are found, clean all components in the hydraulic system and recondition the damaged components.Operational Checks
With the engine running, move the transmission speed selector lever to all positions. The detents should be felt in each position.Operate the machine in each direction and at all speeds. Listen for unusual noises and determine their source. If improper operation is observed, refer to the OPERATIONAL CHECK LIST for "problems" and "probable causes".Operational Check List
Transmission
PROBLEM: Does not operate in any speed or slips in all speeds. PROBABLE CAUSE:1 Low oil pressure due to: a. Low oil level.b. Control linkage broken loose or incorrectly adjusted.c. Oil pump or oil pump drive failure.d. Air leaks on inlet side of pump.e. Leakage within transmission.f. Pressure modulating relief valve spool incorrectly adjusted or stuck open.g. Load piston or differential valve spool stuck.2 Mechanical failure in transmission.3 Torque converter failure.4 Bevel pinion and/or bevel gear failure. PROBLEM: Transmission does not shift. PROBABLE CAUSE:1 Low oil level.2 Low clutch pressures.3 Incorrect linkage adjustment or worn or broken parts. PROBLEM: Sluggish shifting. PROBABLE CAUSE:1 Low oil pressure.2 Incorrectly adjusted internal and external control system linkages.3 Air leaks on inlet side of pump.4 Load piston or differential valve spool sticking in pressure control valve. PROBLEM: Rough shifting. PROBABLE CAUSE:1 Incorrectly adjusted control system linkage.2 Incorrect initial setting of relief valve.3 Sticking load piston and/or differential valve spool.4 Weak or broken valve spring. PROBLEM: Slips in first, second and third forward speeds only. PROBABLE CAUSE:No. 3 clutch slipping