So you're planning to replace your first generation Toyota Sequoia radiator. Great! But while you're at it, here's some things that you should consider doing (aka definitely should do). These are the things I swapped out while doing my radiator replacement for preventative maintenance.
Thermostat
Thermostat is a must-replace when doing the radiator. Even if it seems fine, given how cheap it is and the consequence of it going badly, just replace it while the coolant is drained. This is a no-brainer.
Part number is 9091603100
Available from OEM here: https://toyotaparts.ourismantoyotaofrichmond.com/oem-parts/toyota-engine-coolant-thermostat-9091603100
Fan Clutch
A faulty fan clutch will make all the rest of your cooling maintenance irrelevant. You'll likely experience higher heat at idle and stop & go traffic. The rule of thumb is to replace the fan clutch when you replace the radiator. Don't skimp on this (I learned this the hard way). This AISIN unit is the OEM.
Model number is AISIN FCT-018
Available from ASIN: https://www.amazon.com/gp/product/B00829HC1Q/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1
Or, you can purchase from Toyota under the part number 16210-50090 here: https://toyotaparts.ourismantoyotaofrichmond.com/oem-parts/toyota-clutch-1621050090
Heater Pipes
These are the T-pipes that supply the heater core to the cabin. They can become brittle with age and crack without warning, spraying your engine bay with coolant and potentially overheating the vehicle. They're an inexpensive item to replace at the top of the engine near the fire wall.
Part Number (You'll need QTY 2): 87248-60460
Available from OEM here: https://toyotaparts.ourismantoyotaofrichmond.com/oem-parts/toyota-connector-pipe-8724860460
Heater Control Valve
This is the valve that controls the flow of coolant to the cabin heater and is also susceptible to the same cracking as the heater T-pipes.
Available from OEM here: https://toyotaparts.ourismantoyotaofrichmond.com/oem-parts/toyota-control-valve-872400c010
Hoses & Clamps
Hoses
Take a good look at any of the hoses you encounter while replacing the radiator. Are they cracked or old with corrosion? Have they seen better days? Replace them.
Clamps
There's a good chance some of your clamps will probably be old and tired. Do not replace with AutoZone worm clamps. They will leak. Use "constant tension" OEM style. I've pulled several of these from the junk yard because OEM constant tension clamps are the very best you can get. My current sequoia uses OEM Toyota as well as a big heavy duty clamp I found from a Chevy 6.0.
Extra credit: Coolant Temp Sensor
If you want to make triple sure your radiator swap and cooling system refresh are top notch, you can also replace the coolant temp sensor itself for good measure. It's not a rule of thumb, but I replaced it while I was there given my Sequoia is 21+ years old.
Part Number 89422-30030
Available from OEM here: https://autoparts.toyota.com/products/product/sensor-water-temper-8942230030
Best of luck 🫡