Specifications and Reusability for Hydraulic Gear Pumps and Motors (Groups 4, 5, and 6) {5061, 5073} Caterpillar

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Introduction

Table 1

Revision	Summary of Changes in SEBF9173
21	Updated Effectivity
20	Updated Effectivity
19	Updated Effectivity
18	Updated Effectivity

© 2018 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.

This Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

For questions or additional information concerning this guideline, submit a form for feedback in the Service Information System. To address an urgent issue, use the following resources to communicate your request to Caterpillar Repair Process Engineering:

• Caterpillar Dealer Technical Communicator

• Dealer Solution Network

• Caterpillar Technical Representative

• Knowledge Network

Canceled Part Numbers and Replaced Part Numbers

This document may not include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Summary

This guideline shows visual examples of worn hydraulic pump and motor parts used on Caterpillar machines. Specifically, the guideline shows illustrations of gear pump and motor parts which cannot be used again without salvage operations. All specification previously included in Special Instruction, SEBF8073, "Specifications and Reusability for Hydraulic Gear Pumps and Motors" are now incorporated into this guideline. This guideline also gives other practical information under the "Safety" section. At the bottom of the"Safety" section is a list of items to remember while working with hydraulic gear pump and motor parts, including some basic reuse rules and important addresses.

When used again in the same application, parts that can be used again according to this guideline, can be expected to give normal performance until the next overhaul.

Important Safety Information

Illustration 1	g02139237

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.

Improper operation, lubrication, maintenance, or repair of this product is dangerous. Improper methods could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair of this product, until you understand the operation, lubrication, maintenance, and repair information. Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

Hazards are identified by a safety alert symbol. Safety alert symbols are followed by a signal word such as "Warning" that is shown below.

Illustration 2	g01032906

The following is the meaning of this safety alert symbol:

• Pay attention!

• Become Alert!

• Your safety is involved

The message that appears under the warning explains the hazard. The message will be written or pictorially shown.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and on the product are not all inclusive. If a tool, a procedure, a work method, or an operating technique that is not recommended by Caterpillar is used, ensure that all personnel around the machine are safe. Ensure that the product will not be damaged or that the product will not be made unsafe by the operation, lubrication, maintenance, or repair procedures.

All of the information, specifications, and illustrations that are in this publication are based on information that was available at the time of publication. The following specifications could change at any time: specifications, torque, pressures, measurements, adjustments, illustrations, and other items. These changes can affect the service that is given to the product. Obtain the most current and complete information before you start any job. Caterpillar dealers have the most current information that is available.

Safety

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the steering system.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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NOTICE
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, PERJ1017, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products. Dispose of all fluids according to local regulations and mandates.

• Iron body pumps will cause a damaged look to the gear tooth tips during break-in. This damaged look is caused by the gear tooth tips contacting the rough iron housing of the pump. Along with the damaged look, the tooth tips will also have a lip or burr on the trailing edge. The damage is also caused by contact between the tooth tip and the iron housing.

• Do not install a part again if this guideline shows that the part cannot be used again.

• Do not use a part again if the part has wear or damage that is not shown in this guideline.

• When looking to see if a given part is reusable, be sure to remember the "cause and effect" relation to other parts. Failure, wear, or damage to one part can affect the performance of connected parts. Here is an example of how one problem can be an indication of the source of a larger, future problem. There is light wear on the bearing diameter of the gear shaft. The wear is from contaminants which are embedded in the Teflon material that coats the bearing bores. The condition of the bearing is not easily seen at this early stage. If a new bearing is not installed, the wear will gradually increase and cause failure.

• Most of the illustrations in this guideline are of pumps and not motors. Pumps have a different purpose than motors, but wear and damage characteristics are similar in both. The salvage procedures are the same in both, unless other procedures are given.

• Specifications needed to recondition gear type hydraulic pumps and motors are given in the "Service Manual" and in this guideline.

• The parts in hydraulic pumps and motors work together to give flow or torque. The efficiency of a unit is variable, according to the flow loss that any given groups of parts permit. Be sure to test all rebuilt pumps for acceptable performance. Refer to Special Instruction, REHS1832, "Bench Test Procedure for Gear Pumps" and the "Service Manual" for test specifications.

• Flame Spray is an acceptable method of restoring a surface to the original size. Each step in the procedure is critical in achieving the desired coating bond and the surface finish. Refer to Special Instruction, SEBF9240, "Fundamentals of Flame Spray for Reconditioning Components".

References

Table 2

Media Number	Title
SEBF9236	"Fundamentals of High Velocity Oxygen Fuel (HVOF) Spray for Reconditioning Components"
SEBF9238	"Fundamentals of Arc Spray for Reconditioning Components"
SEBF9240	"Fundamentals of Flame Spray for Reconditioning Components"
SEBF2110	"Thermal Spray Procedures for Pump Gear Drive Inside Diameter"
SEBF2129	"Thermal Spray Procedures for Tyrone Drive Shaft (Pump Gear)"
SEBF2156	"Thermal Spray Procedures for Gear Shafts for Gear Pumps"
SEBF2160	"Thermal Spray Procedures for Bevel Gear Shafts"
REHS1832	"Bench Test Procedure for Gear Pumps"
SEBF8073	"Specifications and Reusability for Hydraulic Gear Pumps and Motors"
SEHS8428	"Removing and Installing Bushings and Pressure Plates in Hydraulic Gear Pumps"
NENG2500	"Dealer Service Tool Catalog"
PEGJ0075	"Loctite ® Cross Reference List for Cat Part Numbers"
SEBF9140	"Specifications and Reusability for Hydraulic Gear Pumps and Motors (Groups 9, 10, and 11)"
SEBF9141	"Specifications and Reusability for Hydraulic Gear Pumps and Motors (Groups 1, 2, and 3)"

Tooling and Equipment

Table 3

Part Number	Part Description
4C-9507	Retaining Compound
6V-6050	Ultrasonic Cleaner Group
7B-0337	Surface Plate
9B-3500	Insert Kit
9B-3700	Insert Kit
Loctite 97453	Loctite ® Fixmaster Epoxy
Loctite AC-4368	Releasing Agent

Pump and Motor Identification Chart

This guideline is for gear pump and motor Groups 4, 5, and 6. Refer to specifications in Table 4 to verify the pump group. Once the pump group has been verified, use Table 4 to choose the correct document number for the pump group. Pumps in Groups 4 and 5 have bodies that are made of aluminum. Pumps in Group 6 have bodies that are made from iron.

Illustration 3	g01438510
Measurements are taken from these locations. (1) Number of gear teeth (2) Gear diameter (3) Journal diameter

Table 4

Pump and Motor Identification Chart
Group	Journal Diameter mm(inches)	Gear Diameter mm(inches)	Number of Gear Teeth	Pressure Plate Thickness mm(inches)	Bushing Style	Document Number
1	44.45 mm (1.75 inch)	77.22 mm (3.04 inch)	10	10.92 mm (0.43 inch)	Flush	SEBF9141
2	31.75 mm (1.25 inch)	60.96 mm (2.40 inch)	10	9.65 mm (0.38 inch)	Flush
3	39.62 mm (1.56 inch)	77.22 mm (3.04 inch)	10	10.92 mm (0.43 inch)	Flush
4	44.45 mm (1.75 inch)	77.22 mm (3.04 inch)	10	7.87 mm (0.31 inch)	Extended	SEBF9173
5	47.50 mm (1.87 inch)	91.44 mm (3.60 inch)	10	7.87 mm (0.31 inch)	Extended
6	47.50 mm (1.87 inch)	91.44 mm (3.60 inch)	10	10.67 mm (0.42 inch)	Flush
7	15.75 mm (0.62 inch)	30.99 mm (1.22 inch)	10	Bushing Block		-
8	22.10 mm (0.87 inch)	44.70 mm (1.76 inch)	10	Bushing Block
9	31.75 mm (1.25 inch)1.25	64.52 mm (2.54 inch)	8	6.60 mm (0.26 inch)	Extended	SEBF9140
10	39.62 mm (1.56 inch)	80.77 mm (3.18 inch)	8	7.87 mm (0.31 inch)	Extended
11	31.75 mm (1.25 inch)	60.96 mm (2.40 inch)	10	6.60 mm (0.26 inch)	Extended

Flange, Plate, and Body Assemblies

Nomenclature

Illustration 4	g01508114
Aluminum flange assembly for Group 4 and 5

Illustration 5	g01508115
Aluminum flange assembly for Group 4 and 5 (4) Extended Bushings (5) Alignment Dowels (6) Body Face

Illustration 6	g01508124
Cast Iron flange assembly for Group 6

Illustration 7	g03394729
Cast Iron flange assembly for Group 6 (obverse) (7) Body Face (8) Flush mounted Bushings (9) Alignment Dowels

Procedure for Cleaning

Remove lip seals and remove weep hole plugs first. Wash the pump flanges, plates, and bodies with clean solvent. Use a petroleum-based solvent. Be sure to clean inner surfaces. Clean the weep hole plugs and seal drain passages. Remove all sealant from the seal grooves. The seal will not seat correctly if the grooves are not cleaned properly. If sealant cannot be removed with the solvent and a brush, use glass beads. Use beads of 80 to 150 micron (size 10) with 585 ± 35 kPa (85 ± 5 psi). Early flanges were equipped with metallic seal drain valves, which are made of Viton material. Before installing a new seal drain valve, a steel sleeve must be installed in the drain valve passage.

Procedure for Inspection

Mounting Face

Illustration 8	g01420737

Illustration 9	g01508722
Fretting on the mounting face of the pump can be an indication that the face is bent. Take two measurements on the face of the pump. One measurement near the pilot diameter (X) and one measurement near the mounting bolt hole (Y).

USE AGAIN

The flange can be used again if the difference between the two measurements is less than 0.5 mm (0.02 inch).

Seal Bore

Illustration 10	g03434192
Light scratches in the seal bore

USE AGAIN

If light scratches are present, apply 4C-9507 Retaining Compound around the joint between the seal case and the bore when installing a new seal. This step will prevent seal to bore leakage.

Illustration 11	g03354266
Damage in the seal bore

USE AGAIN

The seal bore can be repaired. Refer to Section "Procedure for Salvaging the Seal Bore" in this document.

Bushing

Illustration 12	g01420762
An example of normal bushing wear. The bronze is showing through the Teflon.

USE AGAIN

Bronze that is used in the bushings is porous. Because the bronze is porous, the Teflon overlay gets pushed into the pores during manufacturing. Gradual wear in the load zone will cause more of the bronze to show through. The bushing can still be used again because the surface is a mix of bronze and Teflon. The bronze also shows through when the Teflon in the non-load zone of the bushing becomes worn. The bushing can be used again even though the surface may be rough. Refer to Illustration 12.

Illustration 13	g01420764
A scored and spalled bushing

DO NOT USE AGAIN

Note: Bushings that are shown in Illustrations 12 and 13 were cut to allow the condition to be seen.

Illustration 14	g01516600
An example of flush mounted bushings with two different conditions. (10) The Teflon surface is peeling (11) Severely spun bushing

DO NOT USE AGAIN

Illustration 15	g01516596
An example of flush mounted bushings that are in good condition. Iron body pumps that are in Group 6 have flush mounted bearings.

USE AGAIN

Illustration 16	g03434179
The Teflon on the inside diameter of the bushing is peeling.

DO NOT USE AGAIN

Illustration 17	g03434181
The seam of the bushing has turned in the bore.

DO NOT USE AGAIN

Note: Aluminum body pumps that are in Groups 4 and 5 have extended bushings. These illustrations are used for showing different conditions and the illustrations also show raised bushings.

Inspect the bushing bore to see if the bore is out of round after the bushing is removed. If the bushing bore is out of round by more than 0.05 mm (0.002 inch), do not use the casting again. A bushing bore that is out of round is an indication that the gear track is too deep. The pump housing must then be replaced.

The installation of new bushings will affect the efficiency of the unit. When installing new bushings, the gears will move to a new position. This procedure will move the tips of the gear teeth away from the worn gear track. This action causes the pump efficiency to go down. Pump testing is required after all pump repairs to check the pump efficiency.

Illustration 18	g01521333

The bushings must be installed so that the split in the bushings (B) and (C) are positioned toward the alignment dowels (A) and (D). The seams should be 180 degrees away from each other. If the seam of a bushing has rotated in the pump housing, replace the bushing. Refer to Illustration 18.

Illustration 19	g01538356

Illustration 20	g01539055

Some of the pumps use bushings that are equipped with lubrication grooves (F) and (G). These pumps need to have lubrication grooves (F) and (G) toward the alignment dowels (E) and (H), as shown in Illustration 19. This procedure will position the seam of the bushings approximately 30 degrees on either side of the alignment dowels (E) and (H). It does not matter what side of the alignment dowels the seam of the bushing is located on.

Table 5 lists the tooling used to remove and install the bearings. The tool chart lists tooling for either single or tandem version pumps. Refer to Special Instructions, SEHS8428, "Removing and Installing Bushings and Pressure Plates in Hydraulic Gear Pumps" for detailed instructions on replacing the bushings.

Table 5

Tooling
Pump Group	Bushing Removal Tool	Pressure Plate Removal Group	Bushing Installer Group
1	4C-9630	-	135-7275
2	8T-9137	8T-0875	8T-0880
3	8T-9128	8T-9134	8T-9133
4	4C-9630	-	135-7275
5	4C-9631	-	130-5946
6	4C-9631	-	130-5946
7	Bushing Block Design
8
9	8T-9137	8T-0875	8T-0880
10	8T-9128	8T-9134	8T-9133
11	8T-9137	8T-0875	8T-0880

Illustration 21	g01516605
Bushing installer for Groups 4, 5, and 6

If installed incorrectly, some bushing material may be expelled into the bore area. The expelled material happens after the gear shaft and the bushing are staked into the wrong position. Check for any obstructions in the bore of the bushing.

Use the plug gauge to verify correct installation of the bushings in the housing. The plug gauge should slide through the bushing freely. If the plug gauge does not slide through the bushing freely, then there is an issue with the bushing. Remove the bushing and reinstall another bushing. Repeat the process until the plug gauge slides through the bushing freely.

Illustration 22	g01508987
Plug Gauge. Dimensions shown are in inches.

Table 6

Plug Gauge Dimensions
Pump and Motor GP number	Dimension A
4	44.63 mm (1.757 inch)
5	47.70 mm (1.878 inch)
6	47.70 mm (1.878 inch)

Gear Track

Illustration 23	g03394298
(A) This area is the high-pressure side of the pump. Gear track is not allowed in this area. (B) Maximum area of gear track allowed in the housing. (C) This area is the low-pressure side of the pump. Normal gear track area.

The maximum allowable depth in the gear track for an aluminum pump body is 0.38 mm (0.015 inch) on the low-pressure side of the unit.

The maximum allowable depth in the gear track for an iron pump body is 0.28 mm (0.011 inch) on the low-pressure side of the unit.

Normal gear track depth is 0.15 mm (.006 inch) to 0.20 mm (0.008 inch).

Table 7

Housing Gear Bore Diameter
Pump and Motor Group Number	Maximum Gear Bore Diameter
4	77.49 mm (3.051 inch)
5	91.61 mm (3.607 inch)
6	91.56 mm (3.605 inch)

Illustration 24	g01509002
Normal wear for iron body pumps. (12) Body pre-track (13) Gear Track (14) Suction Port

USE AGAIN

Note: Body pre-track (12) is from the machining process during manufacturing. Gear Track wear (13) is normal after break-in test is performed.

Discard the pump if the gear track wear (13) measures deeper than 0.28 mm (0.011 inch) in iron body pumps or 0.38 mm (0.015 inch) in aluminum body pumps.

Illustration 25	g01422124
A burr on the edge of the gear track.

USE AGAIN

Illustration 26	g01516649
Damage that was caused by foreign material.

USE AGAIN

Erosion or damage on the low-pressure side of the gear track will not affect performance. Refer to Illustration 26. If the erosion or damage has extended to the high-pressure side of the pump, do not reuse the pump. Extended damage will result in a loss in efficiency. The loss in efficiency cannot be determined without testing the pump. Test these castings after assembly to be sure that the level of efficiency is acceptable. Pumps with this condition will run at a higher noise level.

Note: The damage is on the low-pressure side. If the damage is extended to the high-pressure side of the pump, do not reuse the pump.

Seal Groove

Illustration 27	g03354287
Sealant in the seal groove

USE AGAIN

Wash the parts with clean petroleum-based solvent after the sealant has been removed. Be sure not to damage the bronze face during the procedure. Remove oil discoloration is not necessary. Remove carbon deposits with the 6V-6050 Ultrasonic Cleaner Group.

Illustration 28	g01422129
Damaged seal groove

DO NOT USE AGAIN

Illustration 29	g01420928
Damaged seal face.

DO NOT USE AGAIN

Illustration 30	g01422134
Damage across the O-ring seal area of the seal face.

DO NOT USE AGAIN

Note: Similar damage across the O-ring groove can cause leakage, as can tool chatter in the bottom of the O-ring groove. Do not reuse the part if the part has either condition. Refer to Illustration 30.

Threads

If the bolt cannot be tightened to the correct torque specifications, the threaded hole is possibly damaged.

Illustration 31	g01516655
Pieces of aluminum in the threads of this bolt are an indication that the threaded hole in the pump is damaged.

USE AGAIN

Remove aluminum from the bolt with a wire brush.

Illustration 32	g03354316
Threaded hole in the pump body is damaged.

USE AGAIN

Use again after repairing the threads with an insert from 9S-3500 UNF Thread Insert Kit or a 9S-3700 UNC Thread Insert Kit.

Miscellaneous

Illustration 33	g01422148
Side clearance can be felt in the dowel hole.

DO NOT USE AGAIN

Note: Do not reuse the mating piece.

Illustration 34	g01510053
Crack in the casting flange

DO NOT USE AGAIN

Illustration 35	g01510075
Crack in the casting flange

DO NOT USE AGAIN

Illustration 36	g01510080
Crack in the casting flange

DO NOT USE AGAIN

Illustration 37	g01510104
Crack in the gear body

DO NOT USE AGAIN

Illustration 38	g01422157
Crack in the seal area of the port

DO NOT USE AGAIN

Procedure for Salvaging the Seal Bore

Most of the damage in the pump flange, plate, and body assembly are either acceptable as is or not at all. If the part is not usable as is, salvage is not practical, except if the damage is seal bore damage. Refer to Illustrations 10 and 11.

Note: Follow the manufacturer directions carefully in the use of Loctite products. Refer to Special Publications, PEGJ0075, "Loctite ® Cross Reference List for Cat Part Numbers" or http://www.useloctite.com/caterpillar.

Use the following procedure to salvage the seal bores.

1. Remove any raised metal in the bore with 180 grit crocus cloth.
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   Illustration 39	g03434165
   Be sure that the bore is clean and dry.

2. Make sure that the bore is free of oil and dirt. Also make sure that the seal bore is dry. Use cleaner or solvent to remove oil. Be sure that the seal bore is dry.
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   Illustration 40	g01422160
   Put Loctite AC-4368 releasing agent on the outside diameter of the seal case.

3. When the part is at room temperature around 21 °C (69.8 °F), put a layer of Loctite AC-4368 releasing agent on the outside diameter of the seal cases.
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   Illustration 41	g03434184

4. Apply an application of Loctite 97453 on the damaged area. Be sure not to get any Loctite 97453 into the seal drain passage. Refer to Illustration 41.

5. After 25 minutes Install the seal in the bore. Do not install the flange assembly for 6 hours.

Gear Shaft

Illustration 42	g01510156
Gear shaft nomenclature. (15) Tooth profile (16) Tooth face (17) Spline (18) Bearing areas (19) Seal area

Procedure for Cleaning

Wash gears with a clean solvent that is made from petroleum. Clean gears carefully to prevent damaging the bearing areas. Removing any discoloration from the gears is not necessary. Oil caused the discoloration and is acceptable.

Procedure for Inspection

Shaft Seal Area

Illustration 43	g03434200
Grooves in the seal area can be felt with a fingernail.

USE AGAIN

Use the shaft again after the seal area is salvaged according to the correct procedure. Refer to the "Procedure for Salvaging Shaft Seal Area" section in this document.

Illustration 44	g03354338
Corrosion in the seal area.

USE AGAIN

Use the shaft again after the seal area is salvaged according to the correct procedure. Refer to the "Procedure for Salvaging Shaft Seal Area" section in this document.

Illustration 45	g03434203
Splines show signs of interference.

USE AGAIN

Use the shaft again after adjusting the shaft installation to prevent interference.

Note: If the splines are twisted on a shaft, do not use the shaft again.

Illustration 46	g03434222
Fretting in the splines can be felt with a fingernail.

DO NOT USE AGAIN

Illustration 47	g03434233
Light spline damage

USE AGAIN

Illustration 48	g03434240
Heavy spline damage

DO NOT USE AGAIN

Journal Area

Illustration 49	g03434254
The journal of the shaft shows wear that was caused by contaminants.

USE AGAIN

When reconditioning the shaft journal, install the shaft in a lathe for proper operation. Use a flat file behind the crocus cloth to polish the journal of the shaft and the tooth face area.

Note: Metal spraying the journal area of the shaft is not recommended.

Illustration 50	g03434996
Corrosion in the journal area and the tooth face.

USE AGAIN

Use 400 grit crocus cloth and motor oil to remove the scratches from the shaft.

Note: If corrosion has caused pitting in the shaft, do not use the part again.

Tooth Face

Illustration 51	g01510356
Scratches on the face of the gear tooth.

USE AGAIN

Use the shaft again after most of the scratches and all of the burrs are removed with 400 grit crocus cloth and motor oil. Install the shaft in a lathe for the correct procedure. Use a flat file behind a piece of crocus cloth to polish tooth face area.

Illustration 52	g03435018

USE AGAIN

Use the shaft again after most of the scratches and all of the burrs are removed with 400 grit crocus cloth and motor oil. Install the shaft in a lathe for the correct procedure. Use a flat file behind a piece of crocus cloth to polish tooth face area.

Note: The area between the journal and the tooth face valley must not contain any scratches. Refer to Illustration 52.

Tooth Profile

Illustration 53	g03435077
Heavy damage on a tooth profile

DO NOT USE AGAIN

Illustration 54	g01516677
Lip on trailing edge of tooth profile

USE AGAIN

Note: The lip on the edge of the tooth tip was caused by the break-in test. This lip is normal in iron housing pumps. Aluminum housing pumps will not cause this type of wear because aluminum will yield to the hardness of the tooth tip. The next three images show normal tooth tip wear in iron housing pumps.

Illustration 55	g01516695
A lip on the trailing edge of the tooth. The lip is normal for iron body pumps.

USE AGAIN

Illustration 56	g01516700
Rough tooth tip edge

USE AGAIN

Note: The rippled look of the tooth tip is normal in iron housing pumps. This rippled look is caused by tooth tip contact with the bore of the iron housing.

Illustration 57	g01516706
Rough tooth tip edge and a lip on the trailing edge of tooth tip.

USE AGAIN

Note: Illustration 57 shows the rippled look on the tooth tip and the lip caused by contact between the tooth tip and bore of iron housing pumps.

Illustration 58	g01510643
(20) Tooth tip wear.

USE AGAIN

Use again if material wear from tip is less than 0.25 mm (0.01 inch).

Note: Significant tooth tip wear only occurs in iron housing pumps.

Table 8

Minimum Allowable Diameter for Gear Tips
Pump and Motor Group Number	New Diameter	Min. Diameter Allowed
4	77.34 mm (3.045 inch)	77.34 mm (3.045 inch)
5	91.44 mm (3.600 inch)	91.44 mm (3.600 inch)
6	91.44 mm (3.600 inch)	91.38 mm (3.598 inch)

Illustration 59	g01421091
Light wear on tooth profile

USE AGAIN

Illustration 60	g01421093
Heavy wear on the tooth profile

DO NOT USE AGAIN

Illustration 61	g01516712
The profile of the gear teeth shows heavy wear.

DO NOT USE AGAIN

Illustration 62	g03435138
Tooth relief for Group 6 pumps

Illustration 63	g03435216
Showing tooth relief at a different angle.

USE AGAIN

Illustration 64	g01519778

Note: Do not confuse tooth relief with tooth profile wear. Tooth relief resembles a flat spot (A) and (B) that are located on one side of the tooth profile. Not all pumps use the tooth relief gears. Only some of the pumps in Group 5 and 6 will have tooth relief on the gears. The gears that have tooth relief must have the idler gear assembled correctly upon installation. The flat spots (A) and (B) of the two gears should be in contact when installed. Do not invert the idler gear. Refer to Illustration 64.

Shaft

Illustration 65	g01516777
Light damage to the end of the shaft.

USE AGAIN

Procedure for Salvaging Shaft Seal Area

Grooves in the seal area that can be felt with a fingernail as shown in Illustration 44 can be removed. Removing the grooves will make the part usable again.

Note: Follow the Flame Spray manufacturer directions carefully in the application of Flame Spray to the shaft seal area. Refer to the bullets at the bottom of the "Safety" section.

Use the following procedure to salvage the area of the shaft seal.

1. Measure the outside diameter of the shaft at the seal area along with the shoulder radius if present. Make a note of each dimension.
   Show/hide table

   Illustration 66	g01516780
   The seal area has been flame sprayed.

2. For the correct Thermal Spray procedures, refer to Table 2 at the beginning of this document.

3. Grind the seal area to the diameter measured in Step 1 to 0.05 mm (0.0020 inch). The surface finish must be 0.40 to 0.80 µm (16 to 32 microinch.). The wheel radius must be the same or greater than the shoulder radius measured in Step 1.

Pressure Plate

Nomenclature

Illustration 67	g01510638
(21) Bronze face. (22) Bearing bore diameter.

Illustration 68	g01510676
(23) Bearing bore diameter. (24) Backup ring groove.

Cleaning Procedure

Wash pressure plates with clean petroleum-based solvent. Be sure not to damage the bronze face during the procedure. Removing oil discoloration is not necessary. Remove carbon deposits with the 6V-6050 Ultrasonic Cleaner Group.

Inspection Procedure

Illustration 69	g01516915
Carbon Deposits on the bronze face.

USE AGAIN

Use the plate again after the carbon is removed by ultrasonic cleaning.

Illustration 70	g01422201
Step in the pressure plate.

The pressure plate can be used again if the step can be removed by touch lapping.

Small surface marks on the bronze face can be removed by a procedure known as "touch lapping". To touch lap, cover the 7B-0337 Plate with 180 grit crocus cloth. Wet the cloth thoroughly with clean petroleum-based solvent. Place the part being touch lapped on the wet cloth with the surface being touch lapped face down on the cloth. Move the part in the shape of the number "8". Wash the part in clean solvent after touch lapping. Allow the part to dry at room temperature.

Check thickness of the pressure plate. The thickness of the pressure plate should not change unless the gears have worn into the pressure plates. Refer to the following table for the thickness of the pressure plates.

Table 9

Pressure Plate Measurements
Pump and Motor Group Number	Minimum Pressure Plate Thickness
4	7.89 mm (0.310 inch)
5	7.92 mm (0.312 inch)
6	10.87 mm (0.428 inch)

Illustration 71	g01422198
Measure pressure plate flatness.

Be sure that the plate is not bent. Check for pressure plate flatness by holding the two plates together with the bronze side facing each other. If a 0.18 mm (0.007 inch) feeler gauge fits between the two plates, then the plates are no longer acceptable.

Illustration 72	g03435239
Scratches in the pressure plate.

USE AGAIN

Illustration 73	g01516920
The erosion is near the pressure equalization chamfer.

USE AGAIN

Illustration 74	g01421108
Smearing on the bronze face

DO NOT USE AGAIN

Illustration 75	g01421110
Pitting on the pressure plate

USE AGAIN

The pressure plate can be used again if the step can be removed by touch lapping.

Miscellaneous Parts

Cleaning Procedure

Clean miscellaneous parts, such as bushing supports, couplings, and support rings with clean petroleum-based solvent.

Note: Never reuse old seals. Always use new seals.

Inspection Procedure

Illustration 76	g03435276
Damaged coupling

USE AGAIN

Reuse if 75 percent of each spline is still in acceptable condition.

Testing Procedure

For the correct break-in procedure refer to Bench Test Procedure, REHS1832, "Bench Test Procedure for Gear Pumps".