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ApplicationCapacities
English Metric
Cooling System – C6/C7/C8 Manual Transmission
7.2L L6 Engine 30.4 qt 28.8 L
7.2L L6 Engine with A/C and Increased Cooling 33.9 qt 32.1 L
Isuzu 6H Engine (207–275 hp) 32.7 qt 31.0 L
Isuzu 6H Engine (207–275 hp) with A/C and Increased
Cooling35.9 qt 34.0 L
Isuzu 6H Engine (300 hp) 36.0 qt 34.1 L
Isuzu 6H Engine (300 hp) with A/C and Increased Cooling 36.0 qt 34.1 L
8.1L V8 Engine 33.3 qt 31.5 L
8.1L V8 Engine with A/C and Increased Cooling 34.9 qt 33.0 L
Engine Oil with Filter
6.6L V8 Engine 14.6 qt 13.8 L
7.2L L6 Caterpillar
®C7 Engine 30.0 qt 28.4 L
Isuzu 6H
1Engine 23.8 qt 22.5 L
8.1L V8 Engine 10.0 qt 9.4 L
Check fill level on the oil indicator after initial fill to make sure it is actually full. Oil level may vary depending on
vehicle option content.
1Additional oil is required with auxiliary oil filter systems. Make sure to add enough extra oil to fill the auxiliary oil
filter system. For vehicles equipped with the LUBERFINER 750-C, add 14 quarts (13.25 L).
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ApplicationCapacities
English Metric
Fuel Capacity – C4/C5 Models
Standard (Mid-Mounted) 25 gal 94.6 L
Optional
1(Dual-Tank) (Mid-Mounted) 40 gal 151.4 L
Optional (Mid-Mounted) 32 gal 121.1 L
Optional (Side-Mounted) 35 gal 132.5 L
Optional (Mid-Mounted) 40 gal 151.4 L
Optional (Mid-Mounted) 60 gal 227.1 L
Optional (Mid-Mounted) 80 gal 302.8 L
1One 25-gallon (94.6 L) tank and one 15-gallon (56.8 L) tank
Fuel Capacity – C6/C7/C8 Models
Optional 35 gal 132.4 L
Standard 50 gal 189.2 L
Optional 50 gal 189.2 L
Optional
1(Dual Tanks) 70 gal 264.8 L
Optional
2(Dual Tanks) 75 gal 283.8 L
Optional
3(Dual Tanks) 100 gal 378.5 L
1Two 35-gallon (132.4 L) tanks2One 25-gallon (94.6 L) tank and one 50-gallon (189.2 L) tank3Two 50-gallon (189.2 L) tanks
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ApplicationCapacities
English Metric
Front 4WD Axle (G38) 7.0 pt 3.6 L
Rear Axle – Single Speed
80 (GL4) 10.0 pt 4.7 L
19060D (HPM), 19060S (HPK), 21060D (HPN),
21060S (HPP), 22060S (HPG)31.0 pt 14.7 L
23090S (HPT) 42.5 pt 20.1 L
23105D (HNB), 23105S (HNA) 51.0 pt 24.1 L
26105S (HPA) 51.0 pt 24.1 L
S110 (HD2) and S130 (HD1) 15.0 pt 7.1 L
Rear Axle – Tandem
DS344 (front) (HPI) 34.0 pt 16.1 L
DS344 (rear) (HPI) 31.0 pt 14.7 L
DS404 (HPE), DS404P (HPJ) (front/rear unit) 32.0 pt 15.1 L
RSH44 (front/ rear unit) (HP3) 29.0 pt 13.7 L
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ApplicationCapacities
English Metric
Rear Axle – Two-Speed
19060T (HPL), 22060T (HPH) 38.0 pt 18.0 L
21060T (H15) 38.0 pt 18.0 L
23082T (H25) 44.0 pt 20.8 L
26080T (GJ4) 44.0 pt 20.8 L
Transfer Case (Four-Wheel Drive) 4.0 pt 1.9 L
Transmission Fluid, Automatic
3000 RDS and EVS, and 3500 RDS and EVS with PTO
Provision59.0 pt 28.1 L
3000 RDS and EVS, and 3500 RDS and EVS without PTO
Provision52.0 pt 24.6 L
1000 HS, RDS, MH, PTS and EVS, 2200 HS, RDS, MH,
PTS and EVS, 2500 HS and RDS, and 2300 HS and RDS35.0 pt 16.5 L
Add 2 pints (1 L) when changing spin-on or remote filter.
See the Allison
®Automatic Transmission Operator’s Manual for fluid check and maintenance information.
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ApplicationCapacities
English Metric
Transmission Fluid, Manual
ES052-7, ES066-7 22.0 pt 10.4 L
FS5205A 12.5 pt 5.9 L
FSO8406, FS6305A, FS6305B, FS6406, FS5406A 19.5 pt 9.2 L
FS4205A, FS4205B 11.5 pt 5.4 L
RT6609 12.0 pt 5.7 L
RT8709 26.0 pt 12.3 L
RT8908LL 28.0 pt 13.2 L
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck the fluid level after filling.
Engine Specifications
Engine RPO Type
6.6L V8 DURAMAX®LMM Common Rail Fuel System
7.2L L6 Caterpillar
®C7 LF6Hydraulic/Electronic Unit Injector
Fuel System
7.8L L6 Isuzu 6H LF8 Common Rail Fuel System
8.1L V8 VORTEC™ L18Single Port Fuel Injector Fuel
System
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Normal Maintenance Replacement Parts
Maintenance Replacement Parts
Replacement parts identified by name, part number, or specification can be obtained from your dealer.
Part GM Part Number ACDelco Part Number
Air Compressor Filter
Haldex compressor (8.1L Engine Only)88915425 A507CF
Engine Air Cleaner/Filter
6.6L V8 (C4/C5 Models) 19152817 A3102C
7.2L L6; Isuzu 6H (C6/C7/C8 Models) with Standard Air
Cleaner88937525 A2031C
7.2L L6; Isuzu 6H (C6/C7/C8 Models) with Heavy Duty Air
Cleaner88937525
1A2031C
8.1L V8 (C4/C5 Models) 88937527 A2032C
8.1L V8 (C6/C7/C8 Models) with Heavy Duty Air Cleaner 88937525 A2031C
8.1L V8 (C6/C7/C8 Models) with Standard Air Cleaner 88937545 A2034C
Engine Oil Filter
6.6L V8 88917036 PF2232
7.2L L6 — 1R-1807
2
Isuzu 6H 94392475 —
8.1L V8 25324052 PF454
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Part GM Part Number ACDelco Part Number
Fuel Filter
6.6L V8 98017645 TP1298B
7.2L L6 — 1R-0751
2
Isuzu 6H 98026037 —
8.1L V8 (C4/C5 with NG6/NK1 or U-Haul) 15807649 —
8.1L V8 (C4/C5 with all other fuel tanks) 10376257 —
8.1L V8 (All C6/C7/C8) 10370247 —
Power Steering Fluid Filter 88892858 —
Secondary Fuel Filter
6.6L V8 — —
7.2L L6 (NWB/KUR) 25982639 S3229
3
Isuzu 6H (NWB) 15618921 S32023
Isuzu 6H (KUK) 88983117 TP1519
8.1L V8 (K28 and standard U-Haul) 25014476 TP1247
Spark Plugs
6.6L V8 — —
7.2L L6 — —
Isuzu 6H — —
8.1L V8 12578277 41-983
1Optional air filter (GM Part No. 88937548 AC Delco No. A2035C) for C6/C7/C8 Models. Fits inside standard size
filter (GM Part No. 88937525 AC Delco No. A2031C) listed previously.
2Caterpillar®part number.3Racor part number.
See the Allison Transmission Operator’s Manual in your vehicle for external filter part numbers and information.
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Engine Drive Belt Routing
A. Air Conditioning Compressor.
B. Dual Generators.A. Air Conditioning Compressor.
B. Air Brake Compressor. 8.1L V8 Engine (C4, C5)
8.1L V8 Engine (C6,C7,C8)
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