2021 GMC Sierra 2500 Cooling System Parts

This table covers the engine coolants and antifreeze formulations specified for this cooling system. Typical signs include a rising temperature gauge, rusty or sludged coolant, or a heater that blows cold. Use the chemistry named in the notes. Mixing silicate, OAT and HOAT formulas can gel in the radiator. Read more

17 Coolant / Antifreeze parts are listed for the 2021 GMC Sierra 2500, from PRESTONE, PEAK, VALVOLINE and 3 other brands. FVP MV5050GAL carries the "Popular" badge. 13 parts fit every engine; the other 4 are engine-specific.

The Compatible With All Colors section lists 1 option from PRESTONE — grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. PRESTONE AF3055 is listed in this group.

In the Economy grade, FVP, PEAK, PRESTONE and 1 other brand supply 4 parts: the catalog's value-priced group. A representative part number is FVP MV5050GAL.

The Heavy Duty section lists 1 option from PRESTONE — rated for severe service. PRESTONE AFC12100 is listed in this group.

The Premium section lists 4 options from PRESTONE and PEAK — a step above OE specification in materials, tolerances or warranty terms. PRESTONE AF2100 is listed in this group.

The Standard Replacement section lists 7 options from VALVOLINE, PRESTONE, ACDELCO and 2 other brands — built to original-equipment specification. ACDELCO 105027 is listed in this group.

This table covers the Coolant Air Bleed Hose pipes. Read more

GM GENUINE supplies the 3 Coolant Air Bleed Hose / Pipe parts for the 2021 GMC Sierra 2500.

Part numbers include GM GENUINE 85056536, GM GENUINE 11549085 and GM GENUINE 85056532.

This table covers the hard pipes and extra hoses in the coolant circuit. Read more

GM GENUINE supplies the 6 Coolant Hose / Pipe parts for the 2021 GMC Sierra 2500. GM GENUINE 85119168 carries the "Popular" badge.

Part numbers include GM GENUINE 85119168, GM GENUINE 85056538 and GM GENUINE 85119158, among others listed above.

This table covers the seals at the Coolant Hose / Pipe. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again. Read more

5 Coolant Hose / Pipe Seal parts for the 2021 GMC Sierra 2500 come from 3 brands — GM GENUINE, MAHLE / CLEVITE and AJUSA. The "Popular" part is GM GENUINE 12658352.

Listed part numbers: GM GENUINE 12658352, AJUSA 16097400 and GM GENUINE 12737097, plus the other parts above.

This table covers the Coolant Hose Connector flanges. Read more

One part is listed for the 2021 GMC Sierra 2500 — GM GENUINE 1510595.

This table covers the Coolant Hose retainers and clips. Read more

GM GENUINE supplies the 4 Coolant Hose Retainer / Clip parts for the 2021 GMC Sierra 2500. 2 parts fit every engine; the other 2 are engine-specific.

Listed part numbers: GM GENUINE 11547354, GM GENUINE 11547355 and GM GENUINE 11549297, plus the other parts above.

This table covers the overflow / expansion tanks that hold extra coolant. Read more

5 Coolant Reservoir parts for the 2021 GMC Sierra 2500 come from 3 brands — GM GENUINE, TECHPRO and DORMAN.

This group includes DORMAN 603093, GM GENUINE 84630072 and GM GENUINE 85639732 and the remaining parts above.

This table covers the caps on the overflow / expansion tank. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable. Read more

7 Coolant Reservoir Cap parts for the 2021 GMC Sierra 2500 come from 6 brands — MOTORAD, DORMAN, SKP and 3 other brands. The "Popular" part is DORMAN 54218. 5 parts fit every engine; the other 2 are engine-specific.

Part numbers include DORMAN 54218, SKP SK54218 and AUTOTECNICA GM0714619, among others listed above.

This table covers the adapters used to pressure-test this cooling system. Read more

MOTORAD supplies both parts for the 2021 GMC Sierra 2500. All of them fit every engine offered in the 2021 Sierra 2500.

This group includes MOTORAD 3128 and MOTORAD 3127.

This table covers the Hose clamps. Read more

GM GENUINE supplies the 7 Hose Clamp parts for the 2021 GMC Sierra 2500. GM GENUINE 11570871 carries the "Popular" badge. 1 part fits every engine; the other 6 are engine-specific.

Listed part numbers: GM GENUINE 11570871, GM GENUINE 11547681 and GM GENUINE 11548976, plus the other parts above.

This table covers the intercoolers that cool turbo or supercharger charge air. Read more

4 Intercooler parts are listed for the 2021 GMC Sierra 2500, from TECHPRO, GM GENUINE, TYC and 1 other brand.

Economy: 1 part, from TECHPRO. A representative part number is TECHPRO GM3012129.

The Standard Replacement section: 1 option from GM GENUINE. GM GENUINE 84747171 is listed in this group.

2 ungrouped parts are not assigned to a grade, with the same engine-level match.

This group includes TECHPRO GM3012129, GM GENUINE 84747171 and TYC 18145 and the remaining parts above.

This table covers the Intercooler Air Hose pipes. Read more

3 Intercooler Air Hose / Pipe parts are listed for the 2021 GMC Sierra 2500, from DORMAN, GM GENUINE and SKP.

Part numbers include DORMAN 667828, GM GENUINE 84870726 and SKP SK84870726.

This table covers the radiators that dump engine heat to airflow through the core. Typical signs include overheating in traffic, a wet core, or coolant that disappears with no puddle. Replace the cap if it cannot hold the rated pressure, and bleed the system after the swap. Read more

14 Radiator parts are listed for the 2021 GMC Sierra 2500, from GPD, CSF, GM GENUINE and 6 other brands. GPD 13885C carries the "Popular" badge. 1 part fits every engine; the other 13 are engine-specific.

Economy: 4 parts, from GPD and TECHPRO. A representative part number is GPD 13885C.

The Standard Replacement section: 10 options from CSF, GM GENUINE, SPECTRA PREMIUM and 4 other brands. CSF 3938 is listed in this group.

This table covers the caps that hold system pressure at the radiator or reservoir neck. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable. Read more

2 Radiator Cap parts are listed for the 2021 GMC Sierra 2500, from ACDELCO and PROFESSIONAL PARTS SWEDEN. All of them fit every engine offered in the 2021 Sierra 2500.

Listed part numbers: ACDELCO RC124 and PROFESSIONAL PARTS SWEDEN 21342353.

This table covers the petcocks used to drain the radiator. Read more

This group shows a single part: GM GENUINE 22790134.

This table covers the Radiator Fan blades. Typical signs include chatter, streaks, or a skip at the top of the stroke. Confirm left and right lengths in the notes — they are often different. Read more

4 Radiator Fan Blade parts for the 2021 GMC Sierra 2500 come from 3 brands — GM GENUINE, DORMAN and GPD.

Listed part numbers: DORMAN 621111, GM GENUINE 1581671 and GM GENUINE 1582003, plus the other parts above.

This table covers the Radiator Fan clutches. Typical signs include slip at highway speed, chatter on takeoff, or a pedal that stays low. Resurface or replace the flywheel with the clutch — a heat-checked flywheel wastes the new disc. Read more

5 Radiator Fan Clutch parts are listed for the 2021 GMC Sierra 2500, from GM GENUINE, FOUR SEASONS, HAYDEN and 1 other brand.

Part numbers include FOUR SEASONS 46145, GM GENUINE 1540608 and GM GENUINE 85824793, among others listed above.

This table covers the brackets that mount the Radiator Fan Motor. Typical signs include a cracked mount, a rattle, or a bracket that no longer holds alignment. Confirm position in the notes. Many brackets look alike and bolt to different corners. Read more

One part is listed for the 2021 GMC Sierra 2500 — GM GENUINE 84182182.

This table covers the Radiator Fan pulleys. Typical signs include a growl or chirp that follows engine speed, or a pulley that will not spin freely by hand. Spin each pulley with the belt off. Roughness or play means replace it with the belt. Read more

GM GENUINE supplies both parts for the 2021 GMC Sierra 2500.

Part numbers include GM GENUINE 12714130 and GM GENUINE 12714129.

This table covers the shrouds that duct air through the fan and radiator. Read more

GM GENUINE supplies both parts for the 2021 GMC Sierra 2500.

Part numbers include GM GENUINE 85112067 and GM GENUINE 87868034.

This table covers the upper, lower and connecting hoses between radiator, engine and reservoir. Typical signs include swelling, cracks, a soft spot, or a leak at a clamp. Replace adjacent aged hoses while the system is drained — they share the same heat cycle. Read more

5 Radiator Hose parts for the 2021 GMC Sierra 2500 come from 3 brands — ACDELCO, GATES and GM GENUINE.

Part numbers include ACDELCO 85119159, ACDELCO 85119166 and ACDELCO 85122989, among others listed above.

This table covers the Radiator Overflow Tube repair kits. Read more

This group shows a single part: GM GENUINE 22799347.

This table covers the senders that report coolant temperature to the gauge or ECU. Typical signs include a gauge that sits on empty or overheat, or a lamp that does not match what the engine is doing. Rule out the cluster and the wiring before replacing the sender. Read more

8 Temperature Sender / Sensor parts are listed for the 2021 GMC Sierra 2500, from ULTRA-POWER, GPD, HOLSTEIN and 5 other brands. ULTRA-POWER 5S13427 carries the "Popular" badge. 7 parts fit every engine; the other 1 is engine-specific.

Economy: 3 parts, from ULTRA-POWER, GPD and HOLSTEIN. A representative part number is ULTRA-POWER 5S13427.

The Standard Replacement section: 5 options from STANDARD MOTOR PRODUCTS, WALKER PRODUCTS, FACET and 2 other brands. STANDARD MOTOR PRODUCTS TX247 is listed in this group.

Listed part numbers: ULTRA-POWER 5S13427, GPD 1712496 and HOLSTEIN 2CTS0184, plus the other parts above.

This table covers the thermostats that open the coolant circuit at the specified temperature. Typical signs include slow warm-up, a gauge that climbs in traffic, or heat that never quite arrives. Replace the housing gasket with the thermostat and bleed the system so a trapped air pocket does not cook the new part. Read more

27 Thermostat parts for the 2021 GMC Sierra 2500 come from 10 brands — MOTORAD, CALORSTAT, GM GENUINE and 7 other brands. The "Popular" part is ACDELCO 131160. Grades run from Economy through Standard Replacement; Standard Replacement is the most populated section, led by MOTORAD, CALORSTAT, GM GENUINE and 4 other brands.

This table covers the seals at the thermostat housing and water outlet. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again. Read more

6 Thermostat / Thermostat Housing / Water Outlet Seal parts are listed for the 2021 GMC Sierra 2500, from GM GENUINE, FEL-PRO, MAHLE / CLEVITE and 1 other brand.

This group includes FEL-PRO 36219, GM GENUINE 12643149 and GM GENUINE 94034146 and the remaining parts above.

This table covers the housings and outlets the thermostat sits in. Read more

8 Thermostat Housing / Water Outlet parts for the 2021 GMC Sierra 2500 come from 4 brands — MOTORAD, FOUR SEASONS, GM GENUINE and 1 other brand. The "Popular" part is FOUR SEASONS 85945.

The Economy section: 1 option from DORMAN. DORMAN 9022081 is listed in this group.

Standard Replacement: 2 parts, from FOUR SEASONS and MOTORAD. A representative part number is FOUR SEASONS 85945.

5 further parts sit outside the graded sections, with the same engine-level match.

Part numbers include FOUR SEASONS 85945, DORMAN 9022081 and MOTORAD CH5945, among others listed above.

This table covers the gaskets that seal the Water Inlet. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

One part is listed for the 2021 GMC Sierra 2500 — GM GENUINE 12587397.

This table covers the pumps that circulate coolant through the block and radiator. Typical signs include coolant at the weep hole, pulley play, or a growl from the front of the engine. Replace the thermostat and refill with the specified coolant whenever the pump comes off. Read more

8 Water Pump parts for the 2021 GMC Sierra 2500 come from 5 brands — GMB, GM GENUINE, ACDELCO and 2 other brands. The "Popular" part is GM GENUINE 251817.

This group includes GM GENUINE 251817, ACDELCO 2521039 and FVP 1303210 and the remaining parts above.

This table covers the gaskets between the water pump and the block or housing. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

5 Water Pump Gasket parts are listed for the 2021 GMC Sierra 2500, from FEL-PRO, MAHLE / CLEVITE and GM GENUINE.

Part numbers include FEL-PRO 36110, FEL-PRO 36109 and GM GENUINE 2512073, among others listed above.

This table covers the Water Pump Inlet tubes. Read more

This group shows a single part: GATES HHA161.

This table covers the Water Pump Seal O-rings. Typical signs include a seep at a fitting or a housing that weeps after a service. Lube the new O-ring with the fluid it will see, and do not roll it into the groove. Read more

2 Water Pump Seal / O-Ring parts for the 2021 GMC Sierra 2500 come from GM GENUINE. 1 part fits every engine; the other 1 is engine-specific.

Part numbers include GM GENUINE 2512031 and GM GENUINE 12643779.