A cab that coats the dashboard in dust within a shift has not lost its air conditioning. It has lost its pressure. Kobelco cabs are designed to run slightly above atmospheric pressure, fed by outside air through a filter and pushed in by the blower, so that dust at every door gap and grommet is pushed out rather than drawn in. When the pressure falls, the dust finds every opening at once. Guangzhou Shenyue Machinery Technology Co., Ltd. supplies the filters and seals involved, and most cases are a filter nobody knew existed.
How the pressure is made
Outside air enters through the fresh-air intake, passes the cab filter, and is pushed into the cab by the blower. Because more air enters than leaks out, the cab sits at a small positive pressure. That pressure is the whole dust defence: it does not need to be large, it needs to exist. Block the intake, collapse the filter, or leave a door seal torn, and the pressure falls to zero within a shift.
The filter most owners never change
Most Kobelco cabs carry two filtration stages: an outer element at the intake and an inner element behind it, often listed as the air conditioner inner filter, YN17M01297F2 in our catalogue. Owners change the outer and forget the inner, which then loads up and restricts flow. On a dusty site the inner element belongs on the monthly list, not the annual one.
Symptoms and what they mean
| Symptom | Likely cause | Check |
|---|---|---|
| Dust on the dashboard within a shift | Filter loaded, or a seal open | Inner filter, door seal, grommets |
| Windows fog and will not clear | Recirculation stuck, or low airflow | Recirculation flap, filter, blower |
| Airflow weak on all speeds | Filter or evaporator fins blocked | Filter, then evaporator face |
| Blower works on one speed only | Blower resistor | Resistor block, connector condition |
| Musty smell, cooling fades after an hour | Evaporator iced or clogged | Evaporator, drain, refrigerant charge |
The openings that break it
A cab is only as tight as its worst gap. Door seals tear at the hinge corner, harness grommets pull out of the floor, the pedal boot splits, and the roof hatch seal flattens with age. A useful test is to close the door with the blower on high and hold a strip of paper at the suspect gap; if it is pulled in, the cab is drawing air there and the pressure is going out somewhere else. Fix seals before blaming the blower.
What dust does beyond the operator
Dust that gets past the filter lands on the evaporator, where it mixes with condensation and sets into a mat. Airflow falls, cooling fades, and the system runs at higher head pressure with the compressor cycling harder. The same dust reaches the blower motor and the resistor. On a site where the machine works in stone or demolition dust, the cab filter and the cooling stack behind it are the two cheapest items on the maintenance list and the two most often skipped.
Setting up a dusty machine properly
Three changes make a measurable difference: move the inner filter to a monthly interval, park with the door closed and the blower off so dust is not drawn in at shutdown, and wash the evaporator face at every filter change rather than waiting for a cooling complaint. If the machine works in fine stone dust, add a spare door seal to the shelf; it is cheaper than the evaporator cleaning it prevents.
What to send us
Send the model, serial, cab type and a photograph of the filter you removed, since build variations changed element styles. We hold three thousand part types on the shelf and over one hundred thousand part numbers available to order through original supply channels, each marked genuine, OEM or aftermarket.
Start from the SK200 model page, the air filter and intake servicing guide or the engine and filter parts range, and send photographs through the contact page. Cab layout and filter locations for each model are published by the manufacturer at kobelco.co.jp.
Guangzhou Shenyue Machinery Technology Co., Ltd. is an independent supplier of Kobelco parts, not affiliated with Kobelco Construction Machinery Co., Ltd. Genuine parts are supplied through original channels alongside quality OEM and aftermarket alternatives at distributor-level prices.
Frequently Asked Questions
Why does dust get into my Kobelco cab?
The cab has lost positive pressure. Either the fresh-air filter is loaded, the inner element has never been changed, or a door seal, grommet or pedal boot is open. A cab is only as tight as its worst gap, so fix the filter and the seals together.
How often should the cab air filter be changed?
Seasonally on general work and monthly in fine dust. Guangzhou Shenyue Machinery Technology Co., Ltd. lists the inner element as air conditioner inner filter YN17M01297F2, and it is the one owners most often leave in place for years because it is hidden behind the outer element.
Can a blocked cab filter affect the air conditioning?
Yes. Restricted airflow reduces cooling, lets the evaporator clog and ice, and pushes head pressure up so the compressor cycles harder. Cleaning the evaporator face at every filter change prevents most of the cooling complaints we hear.
Does cab pressure matter for the operator?
It is the difference between breathing filtered air and breathing site dust for a ten-hour shift. Sealing the cab and keeping the filter clean is the cheapest operator-protection measure on the machine, and it also protects the blower and resistor.