Ask any experienced parts specialist for a Komatsu radiator, and the first question back will always be: which PC200? Not because they're being difficult, but because Komatsu has updated the radiator design multiple times within a single model name as machines move through serial number ranges: PC200-8, PC200-8E0, PC200-8M0, and beyond can all take a different core.
It helps to think of it like ordering a shirt by brand name alone. "Komatsu PC200" tells you the label; it doesn't tell you the size. Two machines wearing the same badge can need a completely different fit underneath, and Komatsu's own parts literature is built around serial number ranges for exactly this reason, not model names.
That's why the serial plate on your machine is always the real source of truth, not the decal on the side panel.
Common Komatsu Radiator Part Numbers by Model
- PC200-8: Widely cross-referenced under 20Y-03-42451, 20Y-03-42450 and 206-03-21411, an aluminium-core radiator with roughly a 915 mm core height
- PC200-8E0 / PC200LC-8E0: Commonly listed as 205-03-31111
- PC300-7, PC350-7, PC360-7: Typically 207-03-71110
- PC300-8, PC300LC-8, PC350-8, PC350LC-8, PC400-7, PC450-7: Commonly 207-03-75121 or 207-03-75120
If your exact PC model or serial range isn't listed here, our full Komatsu Parts collection and Radiators collection are searchable by part number, or you can contact our team with your serial number for a manual cross-check.
Sizing: Why Core Dimensions Matter as Much as the Part Number
Komatsu radiators vary noticeably in core height, width, and thickness across the PC range. A PC200-class core sits at roughly 915 mm high, while larger PC300/PC400-class cores run wider and thicker to handle the extra cooling load of a bigger engine. Getting the size wrong isn't a cosmetic issue:
- A core that's too small for the engine's heat output will overheat under sustained load, even if it physically bolts in
- A core that's too large may not clear the fan shroud or mounting brackets
- Inlet and outlet diameters need to match your hose routing, or you'll be modifying hoses to compensate
Always confirm core height, width, thickness, and inlet/outlet diameter against your machine's spec sheet, not just the part number on a listing.
Picture a workshop that gets a PC200-8 in for a coolant leak. The technician orders a radiator listed simply as "PC200-8 radiator" from a quick online search, without checking the serial plate. When it arrives, the mounting bolt pattern lines up, but the inlet size is wrong for the existing hose, and the core is a slightly different height from the original.
The team ends up modifying hose fittings on the fly just to get the machine back together extra labour, extra delay, and a part that technically "fits" but was never actually the right one. A five-minute check of the serial plate against Komatsu's parts book at the start would have avoided the whole detour.
This is a common, avoidable pattern: the model name gets you close, but only the serial number gets you exact.
Step-by-Step: Replacing a Komatsu PC Series Radiator
- Locate your machine's serial number plate and confirm the exact radiator part number against Komatsu's parts manual for that serial range
- Drain the coolant fully into a proper containment vessel before disconnecting any lines
- Disconnect and inspect all hoses and clamps; replace worn caps and hoses rather than reusing tired ones
- Remove the fan shroud and any guarding needed to access the core
- Unbolt and remove the old radiator, checking mounting brackets and rubber isolators for wear or perishing
- Fit the new radiator, torque mounts to spec, and reconnect hoses with new clamps
- Refill with the correct coolant specification and bleed the system per the service manual
- Run the machine under load and monitor gauge temperature through a full duty cycle before signing the job off
Radiator Overheating? Check the Oil Cooler Too
A radiator that's doing its job but a machine that's still running hot is one of the most common false alarms in the workshop. On many PC series excavators, the hydraulic and engine oil coolers sit right alongside the radiator in the same cooling pack, and a clogged or failing oil cooler can mimic a radiator fault almost perfectly.
If you're chasing an overheating PC200, PC300 or D65-class machine and the radiator checks out fine, our companion guide, Komatsu Oil Cooler Guide: PC200, PC300 & D65 Models, walks through the part numbers and diagnosis for that side of the cooling pack.
