2026 Cadillac CT4 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

10 Coolant / Antifreeze parts for the 2026 Cadillac CT4 come from 3 brands — PRESTONE, VALVOLINE and ACDELCO. The "Popular" part is PRESTONE AF2100. Every part fits all 3 engine options (2.0L L4 Turbocharged, 2.7L L4 Turbocharged and 3.6L V6 Turbocharged).

In the Compatible With All Colors grade, PRESTONE supplies 1 part: grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. A representative part number is PRESTONE AF3055.

The Economy section lists 2 options from PRESTONE and VALVOLINE — the catalog's value-priced group. PRESTONE AF3100 is listed in this group.

In the Premium grade, PRESTONE supplies 2 parts: a step above OE specification in materials, tolerances or warranty terms. A representative part number is PRESTONE AF2100.

In the Standard Replacement grade, VALVOLINE, PRESTONE and ACDELCO supply 5 parts: built to original-equipment specification. A representative part number is VALVOLINE ZXEL1.

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

4 Coolant Air Bleed Hose / Pipe parts for the 2026 Cadillac CT4 come from 2 brands — ACDELCO and GM GENUINE.

Part numbers include ACDELCO 55503533, ACDELCO 55508978 and GM GENUINE 55494528, among others listed above.

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

21 Coolant Hose / Pipe parts for the 2026 Cadillac CT4 come from 2 brands — GM GENUINE and ACDELCO. The "Popular" part is ACDELCO 55515456.

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

GM GENUINE supplies both parts for the 2026 Cadillac CT4.

Part numbers include GM GENUINE 12623519 and GM GENUINE 12640401.

This table covers the Coolant Hose Connector flanges. Read more

4 Coolant Hose Connector / Flange parts for the 2026 Cadillac CT4 come from GM GENUINE. 1 part fits every engine; the other 3 are engine-specific.

Part numbers include GM GENUINE 23333192, GM GENUINE 23171715 and GM GENUINE 84697661, among others listed above.

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

5 Coolant Hose Retainer / Clip parts for the 2026 Cadillac CT4 come from GM GENUINE. 1 part fits every engine; the other 4 are engine-specific.

Listed part numbers: GM GENUINE 11547354, GM GENUINE 88996648 and GM GENUINE 11547862, plus the other parts above.

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

One part is listed for the 2026 Cadillac CT4 — GM GENUINE 23378398.

This table covers the brackets that mount the Coolant Reservoir. 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 2026 Cadillac CT4 — GM GENUINE 84805610.

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

One part is listed for the 2026 Cadillac CT4 — GATES 31569.

This table covers the brackets that mount the Coolant Reservoir Hose. 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

3 Coolant Reservoir Hose Bracket parts for the 2026 Cadillac CT4 come from GM GENUINE.

Part numbers include GM GENUINE 84093181, GM GENUINE 84210348 and GM GENUINE 84333508.

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

This group shows a single part: GM GENUINE 13596789.

This table covers the Hose clamps. Read more

10 Hose Clamp parts for the 2026 Cadillac CT4 come from GM GENUINE. The "Popular" part is GM GENUINE 11570871. 4 parts fit every engine; the other 6 are engine-specific.

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

3 Intercooler parts for the 2026 Cadillac CT4 come from GM GENUINE. 1 part fits every engine; the other 2 are engine-specific.

Listed part numbers: GM GENUINE 84750051, GM GENUINE 84577608 and GM GENUINE 12640408.

This table covers the Intercooler Air Hose pipes. Read more

4 Intercooler Air Hose / Pipe parts for the 2026 Cadillac CT4 come from GM GENUINE.

Part numbers include GM GENUINE 84009657, GM GENUINE 12672014 and GM GENUINE 12672017, among others listed above.

This table covers the brackets that mount the Intercooler Hose / Pipe. 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 84333509.

This table covers the Intercooler Hose / Pipe clamps. Read more

One part is listed for the 2026 Cadillac CT4 — GM GENUINE 13438980.

This table covers the Intercooler retainers and clips. Read more

One part is listed for the 2026 Cadillac CT4 — GM GENUINE 11548857.

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

5 Radiator parts for the 2026 Cadillac CT4 come from 2 brands — GM GENUINE and GPD.

The Economy section: 1 option from GPD. GPD 13889C is listed in this group.

Standard Replacement: 1 part, from GM GENUINE. A representative part number is GM GENUINE 84511252.

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

This group includes GPD 13889C, GM GENUINE 84511252 and GM GENUINE 84908880 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

This group shows a single part: ACDELCO RC124.

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

One part is listed for the 2026 Cadillac CT4 — GM GENUINE 22790134.

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

One part is listed for the 2026 Cadillac CT4 — GM GENUINE 85080140.

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

ACDELCO supplies the 10 Radiator Hose parts for the 2026 Cadillac CT4.

This table covers the brackets that mount the Radiator Hose. 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

GM GENUINE supplies the 4 Radiator Hose Bracket parts for the 2026 Cadillac CT4.

This group includes GM GENUINE 84073805, GM GENUINE 84210352 and GM GENUINE 84210353 and the remaining parts above.

This table covers the brackets that mount the Radiator Mount. 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

GM GENUINE supplies the 3 Radiator Mount Bracket parts for the 2026 Cadillac CT4.

This group includes GM GENUINE 84849419, GM GENUINE 84849420 and GM GENUINE 84849421.

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

9 Temperature Sender / Sensor parts for the 2026 Cadillac CT4 come from 2 brands — GM GENUINE and HOLSTEIN. The "Popular" part is GM GENUINE 55488246.

The Economy section: 4 options from HOLSTEIN. HOLSTEIN 2CTS0331 is listed in this group.

Standard Replacement: 4 parts, from GM GENUINE. A representative part number is GM GENUINE 55488246.

1 further part sits outside the graded sections, with the same engine-level match.

Part numbers include GM GENUINE 55488246, HOLSTEIN 2CTS0331 and HOLSTEIN 2CTS0330, among others listed above.

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

This group shows a single part: 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

One part is listed for the 2026 Cadillac CT4 — MOTORAD 1263189.

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

5 Thermostat / Thermostat Housing / Water Outlet Seal parts for the 2026 Cadillac CT4 come from GM GENUINE. The "Popular" part is GM GENUINE 1532584.

Part numbers include GM GENUINE 1532584, GM GENUINE 12681140 and GM GENUINE 12690764, among others listed above.

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

GM GENUINE supplies both parts for the 2026 Cadillac CT4.

Part numbers include GM GENUINE 12690765 and GM GENUINE 12690768.

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

This group shows a single part: GM GENUINE 55504553.

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

GM GENUINE supplies the 5 Water Pump parts for the 2026 Cadillac CT4.

Listed part numbers: GM GENUINE 12738954, GM GENUINE 12738952 and GM GENUINE 12746198, plus the other 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

2 Water Pump Gasket parts for the 2026 Cadillac CT4 come from 2 brands — ACDELCO and GM GENUINE.

This group includes ACDELCO 2512075 and GM GENUINE 2512052.

This table covers the Water Pump housings. Read more

3 Water Pump Housing parts for the 2026 Cadillac CT4 come from 2 brands — ACDELCO and GM GENUINE.

This group includes ACDELCO 55501820, ACDELCO 12682815 and GM GENUINE 55503850.

This table covers the Water Pump Inlet tubes. Read more

One part is listed for the 2026 Cadillac CT4 — GM GENUINE 55487350.

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

This group shows a single part: GM GENUINE 12611587.

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

GM GENUINE supplies both parts for the 2026 Cadillac CT4.

Part numbers include GM GENUINE 12668035 and GM GENUINE 12691259.