2021 Toyota 4RUNNER 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

18 Coolant / Antifreeze parts are listed for the 2021 Toyota 4RUNNER, from PRESTONE, PEAK, VALVOLINE and 4 other brands. FVP MV5050GAL carries the "Popular" badge.

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 5 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 AISIN, BECK/ARNLEY, VALVOLINE and 2 other brands — built to original-equipment specification. AISIN ACT002 is listed in this group.

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

One part is listed for the 2021 Toyota 4RUNNER — GATES 18336.

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 Toyota 4RUNNER come from 2 brands — APEX and FEL-PRO.

This group includes APEX AWO2184 and FEL-PRO 35654.

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

3 Coolant Reservoir parts for the 2021 Toyota 4RUNNER come from 3 brands — AUTOTECNICA, LARES and TECHPRO.

Part numbers include AUTOTECNICA TY0723939, LARES 37862 and TECHPRO TO3014125.

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

This group shows a single part: MOTORAD T157.

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

MOTORAD supplies both parts for the 2021 Toyota 4RUNNER.

Part numbers include MOTORAD 3124 and MOTORAD 3125.

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

6 Radiator parts are listed for the 2021 Toyota 4RUNNER, from CSF, TYC, FVP and 3 other brands. CSF 3698 carries the "Popular" badge.

This group includes CSF 3698, TYC 13251 and FVP RAD13251 and the remaining parts above.

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

4 Radiator Cap parts are listed for the 2021 Toyota 4RUNNER, from MOTORAD, GATES and SKP.

The Locking Replacement section lists 1 option from MOTORAD — grouped under the catalog's "Locking Replacement" designation — the notes column spells out what sets them apart. MOTORAD ST37 is listed in this group.

The Standard Replacement section: 3 options from GATES, MOTORAD and SKP. GATES 31412 is listed in this group.

Part numbers include MOTORAD ST37, GATES 31412 and MOTORAD T37, among others listed above.

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

2 Radiator Fan Blade parts for the 2021 Toyota 4RUNNER come from 2 brands — GPD and SKP.

Listed part numbers: GPD 2812317 and SKP SK959901.

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

7 Radiator Fan Clutch parts are listed for the 2021 Toyota 4RUNNER, from HAYDEN, US MOTOR WORKS, FOUR SEASONS and 4 other brands. HAYDEN 6631 carries the "Popular" badge.

This group includes HAYDEN 6631, US MOTOR WORKS 22411 and FOUR SEASONS 46106 and the remaining parts above.

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

One part is listed for the 2021 Toyota 4RUNNER — DORMAN 621658.

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 Toyota 4RUNNER come from 3 brands — CONTINENTAL, DAYCO and GATES. The "Popular" part is GATES 23723.

Part numbers include GATES 23723, CONTINENTAL 66502 and CONTINENTAL 66666, among others listed 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

14 Temperature Sender / Sensor parts are listed for the 2021 Toyota 4RUNNER, from STANDARD MOTOR PRODUCTS, ULTRA-POWER, GPD and 10 other brands. ULTRA-POWER 5S1616 carries the "Popular" badge.

Economy: 4 parts, from ULTRA-POWER, GPD, HOLSTEIN and 1 other brand. A representative part number is ULTRA-POWER 5S1616.

The Standard Replacement section: 10 options from STANDARD MOTOR PRODUCTS, DELPHI, ACDELCO and 6 other brands. DELPHI TS10289 is listed in this group.

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

9 Thermostat parts for the 2021 Toyota 4RUNNER come from 9 brands — AUTOTECNICA, SKP, AISIN and 6 other brands. The "Popular" part is AISIN THT003.

The Economy section: 2 options from AUTOTECNICA and SKP. AUTOTECNICA TY0720316 is listed in this group.

Standard Replacement: 7 parts, from AISIN, MOTORAD, ACKOJA and 4 other brands. A representative part number is AISIN THT003.

Part numbers include AISIN THT003, AUTOTECNICA TY0720316 and SKP SK9025148, among others listed above.

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 Toyota 4RUNNER, from FEL-PRO, APEX, MAHLE / CLEVITE and 1 other brand. FEL-PRO 35767 carries the "Popular" badge.

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

5 Thermostat Housing / Water Outlet parts for the 2021 Toyota 4RUNNER come from 5 brands — FAMOUS BRAND, GPD, MOTORAD and 2 other brands. The "Popular" part is MOTORAD CH1038.

The Economy section: 2 options from FAMOUS BRAND and GPD. FAMOUS BRAND 1601335238 is listed in this group.

Standard Replacement: 3 parts, from MOTORAD, ACKOJA and GATES. A representative part number is MOTORAD CH1038.

This group includes MOTORAD CH1038, FAMOUS BRAND 1601335238 and GPD 8241628 and the remaining 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

9 Water Pump parts for the 2021 Toyota 4RUNNER come from 9 brands — ACKOJA, BECK/ARNLEY, FAMOUS BRAND and 6 other brands. The "Popular" part is ACDELCO 252892.

The Economy section: 5 options from ACKOJA, BECK/ARNLEY, FAMOUS BRAND and 2 other brands. ACKOJA A7050022 is listed in this group.

Standard Replacement: 4 parts, from ACDELCO, AISIN, DAYCO and 1 other brand. A representative part number is ACDELCO 252892.

Part numbers include ACDELCO 252892, ACKOJA A7050022 and BECK/ARNLEY 1312488, among others listed 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

3 Water Pump Gasket parts are listed for the 2021 Toyota 4RUNNER, from APEX, FEL-PRO and MAHLE / CLEVITE.

Listed part numbers: APEX AWP3284, FEL-PRO 36014 and MAHLE / CLEVITE K33151.