Hitachi EX300-3

[d9gdon]

This excavator is spitting oil out of the vent plug on the case where the two main pumps are bolted up on the rear of the engine. There is a small pump in the middle of the two big pumps, what is it? There is a dipstick on the case and it is over full as well. This case is bolted to the flywheel housing.

 

[cutting edge]

the small pump in the middle is the pilot pump (low pressure oil that controls the 2 bigger pumps and supplies your joysticks.

The dipstick is for the splitter box oil. One of the 3 pumps is leaking into the splitter. seen this 100 times. start by resealing the pilot pump (quick and easy) and correct the oil type and level in the box. if that doesnt fix it, then get both main pumps shafts resealed and have them looked over at the same time.

 

[d9gdon]

I don't guess I saw your reply, that's what I found out from a Deere dealer tech. I'm working on it now.

 

[cutting edge]

Man , you people talk funny sometimes.

 

[SPMiller]

I don't guess I saw your reply, that's what I found out from a Deere dealer tech. I'm working on it now.

He's a Dealer Mechanic ^

 

[d9gdon]

What kind of oil goes in this gearbox? I thought I saw that it took engine oil in the service manual the other day. That seems too thin for our climate.

 

[excavator]

It calls for engine oil, I think it's 30 wt. I just did a 330-5 and put 40 wt. back in. Either should be fine.

 

[KenAl]

What kind of oil goes in this gearbox? I thought I saw that it took engine oil in the service manual the other day. That seems too thin for our climate.

EX300-3 uses gear oil in the pump drive. 80W-90 is what is listed in the operators manual.
The EX-5 machines is when they changed to engine oil. EX330-5 operators manual calls for 15W-40. We changed to 50 weight engine oil and had better long term reliability here in the north west.
Here is the interesting thing that happened from the EX300-3 to the EX330-5, the drive is the same, same gears etc. Can't remember off hand if the part numbers for the complete drive assembly was the same but the gears, bearings etc were the same. So you would think the oil would be the same. I have seen engine oil in the older ones and gear oil in the newer ones with good results. So just giving you the information so you can make an informed decision for your climate.

 

[d9gdon]

EX300-3 uses gear oil in the pump drive. 80W-90 is what is listed in the operators manual.
The EX-5 machines is when they changed to engine oil. EX330-5 operators manual calls for 15W-40. We changed to 50 weight engine oil and had better long term reliability here in the north west.
Here is the interesting thing that happened from the EX300-3 to the EX330-5, the drive is the same, same gears etc. Can't remember off hand if the part numbers for the complete drive assembly was the same but the gears, bearings etc were the same. So you would think the oil would be the same. I have seen engine oil in the older ones and gear oil in the newer ones with good results. So just giving you the information so you can make an informed decision for your climate.

Good info...now I remember that the service manual I was referring to was for a EX300-5 machine. I'm glad I asked.