Usage:
NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS8951" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
NOTE: This Revised Service Letter replaces the July 26, 1997 Service Letter. Changes have been made to the Service Claim Allowances.
Termination Date
January 31, 1999Problem
Certain 953B and 953C Track-Type Loaders may experience hard starting when the engine is warm or hot. This problem may be due to internal wear of the scroll-edges on the fuel injector plungers. The wear is caused when very fine dirt in the fuel gets past the fuel filter, or by the practice of pre-filling the fuel filter with dirty fuel when the fuel filter is changed during maintenance.
Affected Product
Model & Identification Number
953B *(5MK1-1963 5MK1964-99999 7KL1-99999 )
953C (2ZN1-943)
*These earlier machines, unless previously modified, will be equipped with 1P2299 or 1R0740 Fuel Filter with a 1-inch mounting thread. That filter will be changed to a 1R0750 fine micron 1-inch thread filter during this conversion.
Parts Needed
NOTE: The "Series Filters" Parts List below includes the new Parts Needed to ADD an additional fuel filter on the engine. The new filter is in the "upside-down" position.
- 1 - 4P6379 Film - Fuel filter identification
- 2 - 1R0751 Filter-Fuel-Filter has -inch mounting thread. (Required for S/N 2ZN1-Up and 5MK1964-Up or on S/N 5MK1-1963 machines that have been reworked to use -inch thread fuel filter base.)
-or-
- 1 - 1R0751, 1 - 1R0750 Filter-Fuel and 1-1343589 Film-Fuel Filter Identification (S/N 5MK1-1963 that have 1-inch mounting thread fuel filter base.)
- 1 - 1200201 Base Assembly - Fuel Filter
- 3 - 8T7547 Bolt (M8)
- 3 - 8T4224 Washer
- 1 - 6N4414 Cover - Fuel Filter Base
- 1 - 1P0436 Gasket - Fuel Filter Base Cover
- 1 - 8T4971 Bolt (M6)
- 1 - 9X8256 Washer
- 2 - 8L3282 Connector Flared - STOR
- 7 - 3J1907 Seal-O-Ring
- 2 - 1291090 Valve - Fuel Drain
- 2 - 0037764 End - STOR to Hose Barb
- 2 - 5P4961 Clamp - Hose
- 180cm - 1032529 Hose Bulk - Fuel Drain
- 2 - 3E7410 Tee - STOR
- 1 - 6V8636 Connector - STOR
- 2 - 6V9001 Elbow - STOR to ORFS
- 1 - 5P1318 Adapter - STOR
- 2 - 8T4136 Bolt (M10)
- 3 - 7X7729 Washer
- 1 - 1430915 Bracket As. Fuel Filter Base Mounting
- 1 - 5P4116 Washer
- 1 - 8T4189 Bolt
- 1 - 1318594 Hose As. - ORFS
- 4 - 6V8397 Seal-O-Ring
- 1 - 1116923 Hose As. - ORFS
- 2 - 8T4121 Washer
- 1 - 8T4133 Nut (M10)
- 1 - 8M2773 Clip
- 1 - 1J9671 Seal-O-Ring
- 1 - 8T4182 Bolt (M10)
- 30cm - 5N8359* Conduit
- 3 - 8T7547 Bolt (M8)
*5N8359 Conduit is serviced by Part No. 6V5817.6V5817 is sold by the meter, packaged in 6 meter lengths, and must be cut to size as needed.One order will cover approximately 200 machines.
Action Required
For Machine S/N 5MK1-1963, determine which Fuel Filter will be required for the conversion. If the fuel filter on the engine has a 1-inch filter mounting thread and uses a 1P2299 or a 1R0740 Fuel Filter, order 1 - 1R0750 for that installation.
1. Install the new Series Fuel Filter parts and fuel filter identification film(s). The new filter being added provides additional filtering and is installed "upside-down" to prevent customers from pre-filling with contaminated fuel.
2. If needed, replace worn injectors on machines in service. There have NOT been any changes to the injectors themselves related to the hot starting problem.Injector replacement is not needed unless the machine is experiencing hot hard starting due to worn injectors.
NOTE: After-failure coverage for replacement of worn injectors is intended only for those Customers who use genuine Caterpillar Fuel Filters. Injector replacement expense should be for the customers account if engine is equipped with a non-Cat Fuel Filter.
3. Instruct the customer, operator and/or maintenance personnel concerning the installation of the new series fuel filter part numbers, change intervals, and the need to drain Filter 2 anytime the filter is changed. Provide a copy of the "SERIES FUEL FILTER CHANGE AND MAINTENANCE INTERVAL INSTRUCTION INFORMATION" attached to this Service Letter. Instruct the customer to add the copied sheets to their Operations and Maintenance Guide for the Track Type Loader.
Service Claim Allowances
NOTE: This is a 2.6-hour job.
NOTE: 4.0 additional repair labor hours are required and may be claimed if injector replacement is needed. Use the labor percentage above, based on machine hours or age for participation purposes.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.
- (1-Rework Procedure)
Rework Procedure
Installation Of "Series" Fuel Filters
An additional secondary fuel filter is being added to 3116 engines in Track Type Loaders and, on vehicle S/N 5MK1 through 5MK1963 if the machine has not been previously reworked to a fine micron fuel filter, the No. 1 Fuel Filter is changed to a fine micron fuel filter. The additional "Filter No. 2" is in "series" after the first fuel filter, and provides dual-filtering of the fuel for extra cleanliness. Filter No. 2 also acts as a final "Safety element" similar to the inner element of an air cleaner. Filter No. 2 is installed "upside-down" to prevent the practice of pre-filling filters with fuel that could be contaminated. Both fuel filters are the "High Efficiency" media rated at 2-microns.
NOTE: If injectors are worn, and need to be replaced, we recommend installing a new 1R0751 or 1R0750 Fuel Filter, and operating the machine at High Idle for at least 30 minutes to " flush out " any dirt that may be in the clean-side of the fuel system and cylinder head, before changing injectors. Refer to the "Procedure To Determine If Injectors Are Worn" and "Injector Replacement" for additional information.
Filter Base No 2 Sub-assembly Instructions: Installation of new "upside-down" filter base parts will be easier if the filter base, cover, adapter, tees and fittings are sub-assembled before installing them on the machine. Use the Parts List for Series Filters, the Illustrations provided at the end of this letter and instructions below to sub-assemble parts.
NOTE: Do not tighten fittings, connectors and elbows until all parts below are assembled on the vehicle accept where instructed:
* Install the 6N4414 Cover and 1P0436 Gasket to the new 1200201 Fuel Filter Base, using 1-8T7547 Bolt, 1-8T4224 Washer, and 1-8T4971 Bolt 1-9X8256 Washer. Tighten bolts.
* Install 1-3E7410 Tee and 1-3J1907 O'ring Seal in the"filter-inlet" port of the new fuel filter base so that the in-line port in the tee points "down" after assembly. The intersecting port of the tee should point "right" after the tee is installed. Tighten the Tee in the base.
* Install 1-6V9001 45 Degree STOR to ORFS Elbow and1-3J1907 O'ring Seal in the intersecting port of the 3E7410 Tee from the previous step. Do not tighten the elbow at this time.
* Install 1-5P1318 Adapter and 1-1J9671 O'ring Seal in the "filter-outlet" port of the base, This port pointshorizontal as viewed in the Illustrations. Tightenthe adapter.
* Install 1-3E7410 Tee and 1-3J1907 O'ring Seal into the Adapter at the filter outlet from the previous step. Position the Tee so that the in-line port on the Tee is horizontal and pointing to the "right". The intersecting port of the Tee will point "down" and will be used for a drain valve. Tighten the Tee.
* Install 1-6V9001 45 Degree STOR to ORFS Elbow and1-3J1907 Seal in the in-line port of the 3E7410 Tee from the previous step. Do not tighten the elbow at this time.
* Assemble TWO Drain Valves for installation on the fuel inlet and fuel outlet Tees installed previously. Each Drain Valve is made with 1-8L3282 Connector and 1-3J1907 O'ring Seal, 1-1291090 Valve, and 1-0037764 Hose End (barbed hose end). Use Teflon tape or 5P3413 Sealant on the pipe thread fitting areas at both ends of the valve.
NOTE: The 8C3282 Connectors should be installed in the drain valves so that when the valves are installed the valve lever must be turned "up" to open the valves when they are installed in the Fuel Filter Base Tees. The valve is open when the lever is in line (parallel) with the valve, and closed when the lever is turned 90 degrees (across). DO NOT TIGHTEN THE VALVE PARTS UNTIL THE BASE SUB-ASSEMBLY IS INSTALLED ON THE MACHINE.
* Install the two drain valve assemblies from the previous step into the two open O'Ring ports of the Fuel filter inlet and outlet Tees that point down. Be sure the 3J1907 Seals are in place on the connectors at the top end of the valve assemblies, before installing. Tighten ONLY this connection. Do not tighten the valve and hose-end pipe threads until thetwo hose assemblies are installed and all of the parts are properly positioned.
* Mount the fuel filter base SUB-ASSEMBLY from the previous step to the 1430915 Bracket assembly. Use 2-8T7547 (M8) Bolts, and 2-8T4224 Washers. Mount the SUB-ASSEMBLY so that the fuel filter mounting stud points up from the lower two holes in the mounting bracket. When installing the SUB-ASSEMBLY, square-up the stud side of the SUB-ASSEMBLY with the top of the bracket mounting to insure the filter will be square to engine when the assembly is installed. Tighten the bolts.
Installation On Machine: The engine in the Track Type Loader is installed with the front (fan side of engine) pointing to the rear of the vehicle. For the purpose of this conversion, all instructions are written in reference to the rear of the machine which is the front of the engine.
1. Open up the right access doors of the machine to gain access to the engine fuel filters and fuel system.
2. Disconnect the air cleaner piping from the air cleaner Group and remove the air cleaner canister to gain access to the fuel filter to cylinder head, steel fuel supply line.
3. Remove the original steel fuel line and clip connecting the fuel filter outlet to the rear of cylinder head. Remove the 90 degree elbow from the rear of the head and discard the line, elbow, clip, bolt and washer. See Illustration 2.
4. Install 1-6V8636 STOR to ORFS Connector, 1-3J1907 O'ring (STOR side) in the rear of the cylinder head where the 90 degree fitting was removed in the previous step. Tighten the connector.
5. Loosen the Tee at the original Fuel Filter Base No 1 and turn it 90 degrees so that the fitting end from the removed fuel line points down. Leave Tee loose at this time.
NOTE: Prior to installing the Fuel Filter No 2 Base Sub-Assembly we recommended that the Oil Pressure Switch in the oil manifold on the engine be relocated to improve serviceability of the Sender. See Illustration No 3 for the suggested change. The change is recommended but not required.
6. Locate the two M10 tapped holes in the cylinder block on the right side of the engine as viewed from the rear of the machine and the M8 tapped hole as shown in Illustration 4 and insure that the threads in those tapped holes are clean (It may be necessary to use an M8 and M10 tap to clean the threaded holes).
7. Install the sub-assembled bracket and Fuel Filter Base No. 2 noted in the Sub-Assembly Instructions on the engine using 2-8T4136 (M10) Bolts and 2-7X7749 Washers and 1-8T4189 (M8) Bolt and 1-5P4116 Washer and tighten the bolts. When the assembly is installed the fuel filter mounting stud points "up" so that when the fuel filter is installed it will be "upside down".
8. Install 1-1R0751 Filter on the new Filter Base sub-assembly No. 2 to insure that filter base will remain clean. Tighten the filter one full turn after filter seal contacts the base.
9. Install 1-1116923 Hose to connect outlet of Filter Base No. 1 to the inlet of Filter Base No. 2 (the new filter base). Refer to Illustration 4. Be sure there is a 6V8397 O'ring Seal (face seal) on the face seal tee in Filter Base No. 1 and the 45 degree elbow on the Tee in Fuel Base No. 2 before connecting the hose. When installing the hose, position the Tee and elbow in filter base No. 1 and 2 so that the hose is not crimped nor rubbing any engine component. Tighten the hose to the fittings and tighten the Tee and Elbow in Filter Base No. 1 and 2.
10. Install 1-1318594 Hose Assembly to connect outlet of Filter Base No. 2 to the rear of the cylinder head. Install the 90 degree portion of the hose to the fitting in the rear of the cylinder head and the straight hose fitting to the 45 degree elbow installed in Fuel filter Base No. 2. Refer to Illustration 4. Be sure there is a 6V8397 O'ring Seal (face seal) on the fitting in the cylinder head and 45 degree elbow on Filter Base No. 1 before connecting the hose. When installing the hose, position the 90 degree portion of the hose and the 45 degree elbow in Filter Base No. 2 so that the hose is not crimped nor is it rubbing any engine component or other components on the loader. Tighten the hose to the fittings and tighten the 45 degree elbow in Fuel Filter Base No. 2.
11. Install 1-8M2773 Hose Clip on the 1318594 Hose Assembly noted in step 10 above. Locate the rear Stiffener Strap attached between the Cylinder Head and the Air Cleaner Bracket and remove the bolt and washer that attaches the strap to the bracket. Discard the removed bolt and washer. Use 1-8T4182 Bolt and 1-7X7729 Washer and attach the strap back to the bracket. Fasten the Clip and Hose Assembly to the Air Cleaner Bracket using 2-8T4121 Washers and 1-8T4133 nut to attach the hose and clip to the bracket. Be sure to position the clip and hose so that the hose is not crimped and is positioned so it does not rub other engine or tractor components.
12. Install 30 cm (11.8 in.) length of 5N8359 Conduit on the Hose Assembly installed in step 10 between the clip installed in step 11 and the rear of the cylinder head. Conduit is used as to insure that the hose assembly won't be in contact with other tractor or engine components after installation.
13. Tighten all fittings, tees and connections securely. When tightening drain valves and hose ends with pipe threads, make sure the drain valves are positioned so that drain valve levers are facing AWAY from the engine, and can be reached and operated easily. After tightening, check fuel system again to be sure that hoses do not rub on other engine or loader components.
14. Remove used Fuel Filter No. 1. Install 1-1R0751 or 1R0750 Fuel Filter as appropriate. This step is not needed if a new Fuel Filter was installed as part of the "flushing" procedure prior to injector replacement. It is not necessary to replace Filter No. 1 twice.
15. Cut the 180 cm-1032529 hose in two equal lengths and install the two hoses using 2-5P4961 Clamps to the drain valves. Make sure that each hose hangs freely and extends toward the belly guard access plate below the engine. The hoses are used to provide a means of draining fuel into a container when fuel filter draining is required.
NOTE: If injectors are to be replaced, do not proceed to step 16 until injector replacement (if needed) is completed. Refer to the topic entitled "Procedure To Determine If Injectors Are Worn" for guidance.
16. Insure that the (front) Drain Valve (B) is in the closed position. Open the (rear) drain Valve (A). The open drain valve (A) will allow air venting during priming of the filters.
17. Remove the belly guard access plate, place a container under the drain valve hoses to catch fuel and use the hand priming pump to prime the new filters and fuel system. Stop priming, and CLOSE drain valve (A) when fuel begins to flow out of the drain hose. After closing valve A stroke the priming pump an additional 5 strokes to insure that priming is complete. Be sure to check for leaks while priming.
18. Start the engine, and check all lines, fittings and connections for fuel leaks. Be sure BOTH drain valves for the upside down Fuel Filter No. 2 are CLOSED.
19. Install the 1343589 Film for fuel filter no. 1 and 4P6379 Film for filter no. 2, on vehicle S/N 5MK1-1`963, if the machine has not been reworked with the -inch fuel filter and base, to indicate the proper filters for the engine, or a 4P6379 on other vehicles to indicate that 1R0751 fuel filters are required in the No. 1 and No. 2 Fuel Filter location. Install the film(s) in an area on the engine or vehicle which is visible and close to the fuel filters.
Series Fuel Filter "Change Interval And Maintenance Instruction Information"
NOTE: Use ONLY genuine Caterpillar Fine Micron Filters (2-micron).Use of other filters may result in inadequate filtering and fuel system damage.
The recommended replacement interval for the new Series Filters Conversion is:
Filter Number 1 #250 Hours *1R0751 (original filter location)
Filter Number 2 500 Hours 1R0751 (new "upside-down" filter)
#More often if needed, such as low power or other symptoms due to clogged fuel filters.
*If your machine S/N is 5MK1-1963 and has not been reworked to use a 1R0751 Filter, you will need to use a 1R0750 Filter in the original fuel filter location. The 1R0750 Filter has a 1-inch mounting thread, compared to the 1R0751 which has a -inch mounting thread.
The recommended series filter replacement instructions are as follows:
NOTE: Because this machine is now equipped with series filter it important to remember that the "upside down" inverted filter must always be drained prior to removal.
1. Shut off the fuel tank supply valve.
2. See Illustration 1. Drain the upside down (inverted) filter. To drain, remove the belly pan access plate and place a suitable container under the drain hoses connected to drain valves (A) and (B). Refer to Illustration 1. Open the rear drain valve (A) first and then immediately open drain valve (B). It is important to open these valves as noted as opening the wrong valve first may cause a fuel system air lock and not allow fuel to drain from the upside down filter. Allow fuel to drain. When drainage stops leave valve (A) and (B) open and slightly loosen the upside down filter (loosen approximately one-quarter turn). As the filter is loosened additional fuel may drain from valves (A) and (B). When fuel drainage stops, loosen the filter an additional one-quarter turn and observe flow. Repeat this procedure until fuel no longer drains from the valves. Close valves (A) and (B) and properly dispose the drained fuel.
3. Remove the upside down filter if maintenance is required. If the upside down filter is not being changed, re-tighten the filter. Hand tighten until the seal contacts the base then tighten one full turn.
NOTE: The upside down filter (Filter No. 2) is to be replaced every 500 service hours and the original filter (Filter No. 1) is to be replaced every 250 service hours.
NOTE: Rotation index marks are positioned on the filter at 90 degree intervals. Use these marks as a guide when the filter is re-tightened.
4. Remove Filter No 1.
NOTE: Filter No 1 has not been drained and has fuel in it. Caution should be taken when removing this filter to avoid fuel spillage.
5. Clean the fuel filter mounting base. Make sure that the seal from the filter or filters, if both are being replaced, are not stuck to and on the base.
6. Coat the seal of the new filter, or filters if both are being replaced, with clean diesel fuel.
7. Install the new filter or filters. Hand tighten the filter or filters until the filter seal contacts the sealing surface or surfaces on the bases then tighten the filter or filters one additional full turn.
Rotation index marks are positioned on the filters at 90 degree intervals. Use these marks as a guide when you tighten the filters.
NOTE: When Installingnew filters, NEVER pour fuel into (pre-fill) the new filters. Pre-filling filtersallows dirt and other contamination to bypass filters and get into the fuel system. Dirty fuel and contaminates will damage fuel injectors and result in premature fuel system problems.
8. Open the Fuel Tank Supply Valve which was shut off in step no 1.
9. Prime the fuel system. When priming the fuel system open drain valve (A) to allow air trapped in the filters to escape. Operate the priming pump plunger until fuel begins to flow out the drain valve (A) . When fuel begins to flow out of valve (A) close the valve. Operate the priming pump an additional 5 strokes to insure that the remaining fuel system is primed and all of the air is purged from the fuel lines.
10. Start the engine and check for fuel leaks. Make sure that drain valve (A) and (B) are completely closed before starting.
Illustration 1
Procedure To Determine If Injectors Are Worn
If a Customer is complaining of hard starting at the time that the machine is brought in for the series filter up-date, or the machine demonstrates hard starting prior to the installation of the series filter conversion, it will be necessary to determine if the problem is worn injectors. Following is information that will help you identify if a machine is eligible for injector replacement.
"Hard Starting" symptoms can have several causes. However, it is relatively easy to determine certain causes, and eliminate others by evaluating the specific circumstances when "hard starting" occurs. The following is a list of the most common causes of "hard starting", followed by a discussion of each.
- - Worn Injectors ("hot" hard starting)
- - Control Shaft Sticking
- - Fuel Siphoning (Air In Fuel)
- - Cold Weather
- - Control Shaft Sticking
NOTE: This Program covers ONLY hot hard starting due to worn injectors.
Worn Injectors:
Symptom: Machine is hard to re-start after it reachesnormal "hot" engine operating temperature and is shut-down.Usually, the machine will start easily when the engine is cool, such as the first start of the day. Difficulty re-starting when "hot" (if due to worn injectors) may be due to the loss of injector plunger/barrel pumping efficiency because hot fuel is thinner than cold fuel and plunger/barrel leakage is to high at cranking rpm (200 to 250 rpm).
Test
a) Run the engine until it reaches normal operating temperature and shut it down.
b) Remove the engine valve cover and install the Indicator Fixture Gp. and Indicator as if you were going to check the engine fuel setting (rack setting). See topic "Fuel Setting" in the Systems Operation Test and Adjusting Section of the Engine Service Manual for details on tooling.
NOTE: When installing the fixture gp and indicator it will not be necessary to remove the fuel shut-off solenoid.
c) Zero the Indicator with the fuel shut-off solenoid in the Fuel Shut-off Position.
NOTE: The 953B and 953C utilize an energize to run (ETR) latching type fuel shut-off solenoid which energizes when the key switch is turned to start and the starter engages.
d) After zeroing the indicator turn the key switch to thestart position and crank momentarily to energize thelatching type solenoid. Observe for movement of theindicator. The indicator should move from the 0.0mmposition to a positive position (.5 to 2.0mm). If nomovement is observed, see topic "Control Shaft Sticking".
e) Continue to observe the indicator and turn the key to the off position and then back to the "start" (crank) position. As the engine turns over the rack should start moving from the .5 - 2.0mm position to a higher positive position. As the rack increases observe the point at which the engine fires (starts). It should start when the rack reaches 2.0 to 4.0mm. If the rack increases to more than 4.0mm and the engine fails to start, the injectors are worn and require replacement (See Topic "Injector Replacement" for additional instructions). If the rack fails to move or hesitates to increase as the engine is cranked, see the topic "Control Shaft Sticking".
Control Shaft Sticking: Sometimes "hard starting" can be corrected by exercising the throttle (governor control) while cranking. If the throttle is moved to the full fuel on position, back to idle and then to or throttle position, and the engine starts then the cause of hard starting is not worn injectors. If exercising the throttle allows an engine to start, it means that at the "low idle" position, the governor does not have enough force to open the rack control shaft. Usually, the cause of this problem is an improperly adjusted Fuel Control Shaft Assembly. Exercising the throttle as noted, during cranking, changes the control linkage position and causes the governor to exert more force on the control shaft mechanism thus forcing the injector racks to move and allows the engine to start. This is usually traced to improper control rack as. installation and adjustment. Specifically, adjustment of the two center-supports for the control shaft must be done properly or the shaft may not rotate freely, and may "stick" in the fuel-off position. Refer to Special Instruction Form SEHS9730, Service Magazine Article dated Jan 17, 1996, or the control shaft adjustment procedure given in the "Disassembly and Assembly" part of Engine Service Manual, SENR3611 (04/95) or later, for the control shaft adjustment procedure.
Improper fuel control shaft adjustment usually results in symptoms immediately after installation, such as a new engine, or immediately after repairs involving installation of injectors or the control shaft as. Improper adjustment usually shows up as hard starting when the engine is cold but can also show up when the engine is warm.
Fuel Sophoning (Air In Fuel): If hard starting can be resolved by "priming" the engine with the hand priming pump, then "worn injectors" are not likely the cause.
If an engine starts when primed, the cause is likely to be "fuel siphoning" or "bleed-down". This occurs when fuel leaks from the cylinder head back to the tank and is replaced by air. Air causes a lack of fuel for combustion and results in hard starting. Use "Priming the engine" as an easy diagnostic method to determine if "fuel siphoning" or "bleed-down" is a problem. This symptom usually occurs when the machine has shut off for some period of time such as overnight or over a weekend allowing time for "siphoning" to occur. Therefore, "hard starting" usually occurs at the first start-up of the day. With a "fuel siphoning" problem, the machine will usually start normally when the engine is hot or warm, if it is started shortly after it is shut down. There have been occasional reports of siphoning causing hard starting in as little as one hour.
Fuel siphoning is normally traced to a faulty "return-to-tank" check valve, suction side fuel system leak, or in some cases, injector to cylinder head sleeve leakage.
Cold Weather: Hard starting only in cold weather is NOT due to worn injectors.
If an engine is hard to start when temperatures are below 0 degrees C (32 degree F) the hard starting problem is simply related to cold climate temperatures. There are some cold-weather considerations provided in the " Operation & Maintenance Manual - Cold Weather Recommendations" for Cat Machines. See that information. The following represent some of the items to consider if cold hard starting occurs:
* Use "No. 1" grade diesel fuel, or kerosene mix to improve starting.Check the fuel API rating.
* Cold Cranking RPM - If engine "cranks" too slowly (normalcranking is 200 to 250 rpms) check the battery, electrical system, battery capacity, cable size, connections etc.
* Use a lighter weight engine oil suitable for the coldclimatic temperatures. Refer to Operation & Maintenance Manual.
* Use "Starting Aids" such as electric coolant heater (block heaters), Ether Starting Aids, etc.
* Many machines with 3116 Engines now offer the Electric Air Inlet Heater System as a starting aid. By pre-heating the electric heater element in the air inlet system, the inlet air is warmed during cranking to improve start-ability. Air Inlet Heater (AIH) systems can be refitted to most machines with 3116 engines, if needed. Refer to the November 6, 1995 and September 27, 1993 Service Magazine articles, "Dealer Installed Air Inlet Heater Starting Aid Available" for information.
Injector Replacement
Flush Procedure (Before installing new injectors)
If injectors are to be replaced due to hot hard starting, it is possible there may be dirt in the "clean" or "filtered" side of the fuel system. Therefore, before replacing worn injectors it is recommended to "flush" the system to make sure the filtered side of the system is as clean as possible BEFORE installing the new injectors. This may be done either before or after installing the new Series filter update.
NOTE: If Series filter update has already been done, then proceed to Step 2.
1. Remove the existing used fuel filter, and install a NEW or 1R0751 or 1R0750 Fuel Filter depending upon the thread of the original filter in the No. 1 fuel filter location. DO NOT FILL THE NEW FILTER WITH FUEL. Use the hand priming pump to prime the filter.
2. Start the machine, and run the engine at High Idle for at least 30 minutes, or longer. This will allow any dirt in the clean side to "flush" back to tank. The new filter will provide clean fuel during the flushing time.
Replacement Procedure
1. During injector replacement, do not open the box of each new injector until it is time to install it. Leaving the new injectors open exposes them to fine dust which then is installed with the injector.
2. During injector replacement, do not remove all the injectors at the same time. Instead, remove only one injector and replace it with a new one, before proceeding to the next injector. This will minimize the amount of dust that gets into the injector hole while the injector is removed.
3. When replacing injectors, be sure to ream the brass sleeve before installing the new injector. If brass sleeve replacement is needed, replace each sleeve separately including reaming, and install a new injector before going to the next injector. Also, be sure to remove all the small particles from the reaming process. Use a small amount of spray solvent to wash the injector hole and sleeve before installing the injector.
4. Do not open the box of the new injector until ready to put it in the cylinder head. Servicemen should clean their hands on a clean shop towel as much as possible to avoid getting dirt on the new injectors when handling them. Do not "wipe" the oil off the injector before installing it. Some of the very fine dirt on a wiping towel or cloth will be left on the injector.
Illustration 2
Illustration 3
