Hitachi Ex270 Hydraulic Pump Bleeding

[Joe Quint]

I’m supposed to bleed the hydraulic pump of air since I changed out the hydraulic fluid but the plugs are seemingly impossible to get off and I’m not positive I’m trying to take off the right part. Any help would be appreciated. I can’t seem to get my impact on it because it’s a enclosed space either. The plug is what I’m pointing to with a zip tie.

Is it possible that Hercules tightened these on there?

 

[Diesel Dave]

If there is no room for an impact , a 3/4 drive socket and breaker bar is what you need to loosen those plugs.

 

[Joe Quint]

I’ve been workin on that with the 3/4 and a breaker bar, heat, brake fluid, and pb blaster. As long as that is the right plug I’ll keep working it

 

[LACHAU]

Actually,
You only have to vent the air when replacing the main pump.
When you only change the hydraulic oil, you do not need to bleed the air.
Anyway, If those two screws are too difficult to open; You can release air by loosening the main pump's drain hoses.

 

[Joe Quint]

That sounds amazing about the drain hoses!

Which ones are the drain hoses? I marked two hoses in red (see attached). Are those the drain hoses?

I checked the orange dipstick on the left and it was dry.

 

[LACHAU]

That sounds amazing about the drain hoses!

Which ones are the drain hoses? I marked two hoses in red (see attached). Are those the drain hoses?

I checked the orange dipstick on the left and it was dry.

That stick is the pump transmission oil level dipstick.
Regarding to drain hose. It is a hose connected from the main pump case to the filter and then from the filter to the tank (or directly to the hydraulic tank).

 

[Joe Quint]

thank you guys for the specific help on this one. I looked in another manual and found this drawing(see below). Definitely reaffirms I’m on the right track with it. I assume the rubber o ring is possibly causing me some grief because it’s 20 years old.

 

[Joe Quint]

Is there any major issue with using heat on the regulator? To get the plug off?

 

[Joe Quint]

i suspect that the plugs wasn’t installed with proper torque. Since it is supposed to be 58ft lbs. I put at least 400 ft lbs on it. So much so I could see the 3/4 break bar bending under the torque.

Maybe it’s a chemical welding situation too. I dunno.