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SKU:
NLT2E01484
Ships for free in 2–4 business days.
Engine Thermostat for Komatsu PC27 PC30 PC35 PC45 PC50 PC55 Mini Excavators Replaces YM129155-49801
$27.99
In Stock
$27.99
Sale price
$27.99
Regular price
This aftermarket engine coolant thermostat replaces YM129155-49801 for compatible Komatsu mini excavators using select 3D88E and 4D88E engines.
Estimated delivery between
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Compatible Models
We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.
Compatible equipment / model
- Komatsu PC27MR-1
- Komatsu PC27MR-2
- Komatsu PC27MR-3
- Komatsu PC27R-8
- Komatsu PC30MR-2
- Komatsu PC30MR-3
- Komatsu PC35MR-2
- Komatsu PC35MR-3
- Komatsu PC35R-8
- Komatsu PC45R-8
- Komatsu PC45MR-3
- Komatsu PC50MR-2
- Komatsu PC55MR-3
- Yanmar 3D88E engine applications with matching thermostat
- Yanmar 4D88E engine applications with matching thermostat
Product Overview
A thermostat stuck closed can send coolant temperature up fast; one stuck open can leave the engine running cold with slow warm-up and weak cab heat.
For the repair to hold up, the part still has to match the original application. This replacement regulates coolant flow once the engine reaches operating temperature. Check coolant level, radiator flow, fan operation, and temperature-sender accuracy as part of the diagnosis.
Key Features & Performance
- Controls coolant flow during warm-up
- Fits compatible 3D88E and 4D88E applications
- Drop-in replacement style
- Helps restore stable operating temperature
Replaces Part Numbers
- YM129155-49801
- 129155-49801
Common Uses
- Replacing a confirmed failed or damaged engine coolant thermostat
- Correcting the symptoms described in the product overview after testing related parts
- Restoring dependable operation during repair or scheduled service
- Matching one of the listed reference numbers or compatible applications
Technical Specifications
- Product Type: Engine coolant thermostat
- Compatible Brand: Komatsu / Yanmar engine applications
- Cooling System Role: Temperature regulation
- Replacement Type: Aftermarket
Installation & Fitment
- Service only on a cold engine
- Drain coolant below thermostat level
- Install in the original direction with the correct seal
- Refill, bleed air, and watch temperature closely during the first heat cycle
Compatibility Notice
Northline Parts does its best to list all known compatible models, but the correct part may fit an application not shown.
Model names alone do not guarantee fitment. Production dates, serial-number breaks, engine packages, wiring, and installed options can change the part used on otherwise similar equipment.
Frequently Asked Questions
Q: What problem is this part commonly used to address? A: A thermostat stuck closed can send coolant temperature up fast; one stuck open can leave the engine running cold with slow warm-up and weak cab heat.
Q: How should fitment be confirmed? A: Match the original part number first, then compare the connector or fittings, mounting points, dimensions, and machine or engine serial information.
Q: Is this an original equipment manufacturer part? A: No. This is an aftermarket replacement part for compatible applications.
Q: Can another fault cause similar symptoms? A: Yes. Wiring, grounds, hoses, filters, related controls, and mechanical wear should be tested as part of the diagnosis.
Q: What should be checked after installation? A: Confirm secure connections, normal operation, and no leaks, heat, binding, or warning indications before returning the equipment to service.
Part Summary
keywords: Komatsu thermostat replacement, YM129155-49801 fit, PC35MR overheating repair, PC50MR slow warm up, 4D88E thermostat, mini excavator cooling system part
Brand names, model numbers, and reference part numbers are used for identification and compatibility purposes only. Verify the original component, dimensions, and application before purchase.