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[Mikeyp756]

Hey guys, I’ve been running aw46 in my hitachi ex120-2 as I been working on various problems. As a substitute only with zinc. Now I noticed the aw46 says “not recommended for wet brakes” on the bucket. What hydraulic fluid should I be running.

 

[Nige]

Hey guys, I’ve been running aw46 in my hitachi ex120-2 as I been working on various problems.......... What hydraulic fluid should I be running.

For an Hitachi, anything ISO46 zinc-free. Most of the major oil companies manufacture a zinc-free hydraulic oil, one that comes to mind is Conoco EcoTerra but all the major companies will make one.

 

[Mikeyp756]

I appreciate the reply Nige but my concern right now is will aw46 (with zinc) effect the swing brake and/or turn foggy

 

[Coy Lancaster]

A lot of the brakes for excavators are a different material than what is on backhoes or dozers. You might want to see what is recommended for your machine.

 

[John C.]

Swing and travel brakes are parking brakes. The don't work the same as service brakes in a truck or wheel loader. They are not meant to bring things to a sliding stop. Every place I've ever worked and most all the customers I've called on used AW46 in their hydraulic systems. You do need to obtain an operation and maintenance manual for your machine and review fluid specifications. Hitachi excavators generally use gear oil in the swing and travel reduction gears. The parking brakes are on the motor sides of those components and run in the hydraulic oil.

 

[Mikeyp756]

What I’m concerned about is the iso46 that I’ve been using says “not recommended for wet brakes” isn’t the swing brake considered a wet brake?

 

[funwithfuel]

As John C stated, it is not a service brake. They are parking or holding brakes. Just to keep things static.
The whole not recommended for wet brakes is for service brakes like loaders and haulers that use the brakes to reduce speed to a stop. For those applications you would use Mobil 424 or mfr specific wet brake oil.
You are fine the way you are, AW46 shouldn't cause you any grief

 

[Mikeyp756]

Thank you very much funwithfuel. That’s basically what I wanted to hear. And my apologies to John c for not quite getting his point.