Cat 326-4689 Open Crankcase Ventilation Element

What exactly is this thing?

The 326-4689 is open crankcase ventilation element — the filter that lives in your engine's crankcase breather system. In plain terms, it's the part that catches whatever tries to escape the crankcase: oil mist, soot, and the blow-by gases that slip past the piston rings under pressure. None of it should reach the open air, and none of it should make its way back into the intake, either.

It is a standard-efficiency element, which suits normal-duty applications just fine. The housing is molded from polyamide plastic — light, tough, and built to hold up to years of heat, vibration, and the general abuse an engine room dishes out.

What happens if you ignore it?

Skip the maintenance on this little filter and the bill shows up later, usually in one of three ways:

1.Crankcase pressure climbs. Oil starts pushing past seals and gaskets that were doing just fine, and suddenly you're chasing leaks across the whole underside of the engine.

2.The breather starts drawing in unfiltered air — air full of the dust and grit the filter was supposed to stop.

3.Sludge builds up in places that are a pain to clean, and oil consumption creeps up for no reason you can pin down.

Filters are cheap. Engines aren't. That's the whole math, really.

Does it fit your machine?

This is where the 326-4689 really earns its keep — it covers a big slice of Cat's lineup:

Industrial engines: C9, C9.3, C9.3B, C13, C15, C18, 3516B

Excavators: 336E family (336E, 336E L/LN/LH/LNH/HVG), 349E family, 350, 568 FM

Wheel loaders: 966K/M, 972K/M, 980K/M, 982M, including XE variants

Motor graders: 12M, 140M, 160M Series 2 and 3

Track-type tractors: D6, D6T, D7, D7E, plus LGP/XL/XW variants

Articulated trucks: 725, 725C

Cold planers: PM310, PM312, PM313

Pipelayers: PL72

Scrapers: 621H, 623H, 627H, 627K, 637, 637K

Plus: power modules, generator sets (XQ330, XQP310, LC51XX), and powertrain packages

If you run any of these, the 326-4689 is very likely your part.

When should you replace it?

1.You're seeing oil weep around.

2.The element looks soaked, dark, or visibly blocked .

3.Oil consumption has crept up.

4.It's simply been longer than your maintenance schedule allows — breather elements are a wear item, not a set-and forget part .

A quick word on installation

The swap itself is straightforward: pull the old element, seat the new one, and make sure the breather line is clear before you button it up. If your machine has a blow-by indicator, connect the indicator, and slowly open the crankcase ventilation valve until the reading settles where it should. Ten minutes of care here saves you from chasing an imaginary problem later.

Bottom line

The 326-4689 is one of those parts that's easy to ignore — and expensive to ignore for too long. It keeps your engine's breathing system clean, keeps oil where it belongs, and keeps the machine earning instead of sitting.

Cross-reference part numbers: 326-4689 / 3264689 / CA3264689