2021 Chevrolet Blazer 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 Chevrolet Blazer, 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

6 Coolant Air Bleed Hose / Pipe parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE and ACDELCO.

This group includes ACDELCO 55507188, GM GENUINE 55487843 and GM GENUINE 55487839 and the remaining parts above.

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

12 Coolant Hose / Pipe parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE and ACDELCO. GM GENUINE 55509175 carries the "Popular" badge.

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

2 Coolant Hose / Pipe Seal parts for the 2021 Chevrolet Blazer come from 2 brands — FEL-PRO and GM GENUINE.

This group includes FEL-PRO 36156 and GM GENUINE 12627055.

This table covers the Coolant Hose Connector flanges. Read more

One part is listed for the 2021 Chevrolet Blazer — GM GENUINE 23333192.

This table covers the seals at the Coolant Hose Connector / Flange. 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

This group shows a single part: ELRING 237180.

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

GM GENUINE supplies both parts for the 2021 Chevrolet Blazer. 1 part fits every engine; the other 1 is engine-specific.

This group includes GM GENUINE 11548672 and GM GENUINE 15041309.

This table covers the gaskets that seal the Coolant Pipe. 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

This group shows a single part: ELRING 237170.

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

7 Coolant Reservoir parts for the 2021 Chevrolet Blazer come from 6 brands — TECHPRO, DORMAN, GM GENUINE and 3 other brands. The "Popular" part is DORMAN 603861. Every part fits all 3 engine options (2.0L L4 Turbocharged, 2.5L L4 and 3.6L V6).

Listed part numbers: DORMAN 603861, GM GENUINE 23386455 and GPD 2411160, plus the other 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

6 Coolant Reservoir Cap parts for the 2021 Chevrolet Blazer come from 6 brands — DORMAN, SKP, AUTOTECNICA and 3 other brands. The "Popular" part is DORMAN 54218. Every part fits all 3 engine options (2.0L L4 Turbocharged, 2.5L L4 and 3.6L V6).

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 Chevrolet Blazer. All of them fit every engine offered in the 2021 Blazer.

This group includes MOTORAD 3128 and MOTORAD 3127.

This table covers the Hose clamps. Read more

GM GENUINE supplies the 16 Hose Clamp parts for the 2021 Chevrolet Blazer. GM GENUINE 90572594 carries the "Popular" badge. 1 part fits every engine; the other 15 are engine-specific.

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

2 Intercooler parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE and TYC.

This group includes GM GENUINE 85557764 and TYC 18150.

This table covers the Intercooler Air Hose pipes. Read more

One part is listed for the 2021 Chevrolet Blazer — GM GENUINE 84157174.

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

11 Radiator parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE, UAC, TYC and 5 other brands. GM GENUINE 85797937 carries the "Popular" badge.

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 Chevrolet Blazer, from ACDELCO and PROFESSIONAL PARTS SWEDEN. All of them fit every engine offered in the 2021 Blazer.

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 23444086.

This table covers the fan assemblies (and clutches, where listed) that pull air through the radiator. Read more

12 Radiator Fan Assembly parts for the 2021 Chevrolet Blazer come from 8 brands — GM GENUINE, GPD, SKP and 5 other brands. The "Popular" part is FOUR SEASONS 75197.

The Economy section: 4 options from GPD, SKP, TECHPRO and 1 other brand. GPD 2812298 is listed in this group.

Standard Replacement: 8 parts, from GM GENUINE, FOUR SEASONS, TYC and 1 other brand. A representative part number is FOUR SEASONS 75197.

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

15 Radiator Hose parts for the 2021 Chevrolet Blazer come from 4 brands — ACDELCO, GATES, GM GENUINE and 1 other brand. The "Popular" part is ACDELCO 23253702.

This table covers the seals at the Radiator. 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

4 Radiator Seal parts for the 2021 Chevrolet Blazer come from GM GENUINE.

Listed part numbers: GM GENUINE 84672585, GM GENUINE 84672586 and GM GENUINE 23100851, plus the other parts above.

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

22 Temperature Sender / Sensor parts are listed for the 2021 Chevrolet Blazer, from HOLSTEIN, GM GENUINE, STANDARD MOTOR PRODUCTS and 6 other brands. GM GENUINE 55488246 carries the "Popular" badge.

Economy: 8 parts, from HOLSTEIN, GPD and UNITED MOTOR PRODUCTS. A representative part number is GPD 1814555.

The Standard Replacement section: 14 options from GM GENUINE, STANDARD MOTOR PRODUCTS, WALKER PRODUCTS and 3 other brands. GM GENUINE 55488246 is listed in this group.

This table covers the Temperature Sender / Sensor clips. Read more

One part is listed for the 2021 Chevrolet Blazer — DORMAN 66264.

This table covers the Temperature Sender / Sensor 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

One part is listed for the 2021 Chevrolet Blazer — GM GENUINE 12639042.

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

14 Thermostat parts for the 2021 Chevrolet Blazer come from 7 brands — MOTORAD, FOUR SEASONS, GATES and 4 other brands. The "Popular" part is GATES 34717.

The Economy section: 3 options from AUTOTECNICA, DORMAN and SKP. AUTOTECNICA GM0720261 is listed in this group.

Heavy Duty: 1 part, from MOTORAD. A representative part number is MOTORAD 5860203.

Standard Replacement: 8 parts, from MOTORAD, GATES, FOUR SEASONS and 1 other brand. A representative part number is GATES 34717.

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

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

10 Thermostat / Thermostat Housing / Water Outlet Seal parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE, MAHLE / CLEVITE, ELRING and 2 other brands. GM GENUINE 12630780 carries the "Popular" badge.

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

11 Thermostat Housing / Water Outlet parts for the 2021 Chevrolet Blazer come from 6 brands — GM GENUINE, VEMO, GATES and 3 other brands. The "Popular" part is DORMAN 9022087.

The Economy section: 4 options from VEMO, DORMAN and SKP. DORMAN 9022087 is listed in this group.

Standard Replacement: 5 parts, from GM GENUINE, MOTORAD and GATES. A representative part number is GM GENUINE 1581764.

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

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

4 Water Inlet Gasket parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE, FEL-PRO and MAHLE / CLEVITE.

Listed part numbers: FEL-PRO 36167, GM GENUINE 55504553 and GM GENUINE 12647400, plus the other parts above.

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

28 Water Pump parts for the 2021 Chevrolet Blazer come from 11 brands — GM GENUINE, FVP, US MOTOR WORKS and 8 other brands. The "Popular" part is US MOTOR WORKS US8102. Grades run from Economy through Standard Replacement; Standard Replacement is the most populated section, led by GM GENUINE, GATES, GMB and 4 other brands.

This table covers the brackets that mount the Water Pump. 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

This group shows a single part: GM GENUINE 55497659.

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

9 Water Pump Gasket parts are listed for the 2021 Chevrolet Blazer, from GM GENUINE, ELRING, FEL-PRO and 1 other brand. GM GENUINE 2512072 carries the "Popular" badge.

Listed part numbers: GM GENUINE 2512072, ELRING 048370 and ELRING 048320, plus the other parts above.

This table covers the Water Pump Inlet tubes. Read more

This group shows a single part: GM GENUINE 12706857.

This table covers the Water Pump 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

One part is listed for the 2021 Chevrolet Blazer — GM GENUINE 12652047.