hydraulic hammer is weak

[YAHYA]

hello my friends

I bought volvo EC290 Cnl.
and i have problem with my hammer its so weak.
can you pls help me.
thank you.

 

[DEMLONE70]

Did it work ok before ?
Whats flow and pressure hammer needs ?

 

[YAHYA]

I made sure the pressure and flow weren't a problem with them.
The problem is somewhere else, I don't know where.

 

[Tones]

Check the gas in the hammer. It's the gas that gives the punch not the hydraulics.

 

[YAHYA]

There is no problem with gas
My problem in selector i think

 

[Mike85]

Post your flow and pressure from the excavator as well as the nitrogen pressure from the hammer please

 

[Tones]

OK. Now does the return line from the hammer return to tank or return to circuit. Does it have a filter on the return line?

 

[92U 3406]

What model hammer and what is your nitrogen pressure in the accumulator(s)? Low nitrogen it will hit very fast and very light.

Are you setting pressure/flow with the monitor in the cab? Those are NOTORIOUSLY inacurate and I would not put my faith in that (trust me I see that issue pop up with alarming frequency).

Are you in 1 way hydraulic mode?

Hydraulic couplers can be another issue. Far too many run cheap-*** threaded couplers that either back off from vibration or just don't flow worth a crap to begin with.

 

[terex herder]

I was warned the standard quick couplers won't stand up to hammer usage and when they come apart it can ruin the hammer. Either use quick couplers from a hammer manufacturer, or couple the hammer direct.

 

[92U 3406]

Never had an issue using a good quality flat face coupler.

Direct connect, flat face or locking threaded are the only methods we use.

 

[Tones]

I was warned the standard quick couplers won't stand up to hammer usage and when they come apart it can ruin the hammer. Either use quick couplers from a hammer manufacturer, or couple the hammer direct.

Same here, they won't stand up to the pulsing oil. In fact I have never seen a hammer with quick connects.

 

[92U 3406]

Haven't had an issue with these ever:

You definitely want to avoid the ones with the tit on top of the poppet. You might get an afternoon out of them before they get pounded apart. Plus those ones don't flow worth a damn either.



These are absolutely the best you could buy IMO. Just be prepared to write a big cheque because they are not cheap.

 

[YAHYA]

OK. Now does the return line from the hammer return to tank or return to circuit. Does it have a filter on the return line?

Yes the return line divided to two lines.
One goes to filter and the other goes to circuit

 

[Tones]

I take it that there only 2 lines connected to the hammer. Are there 2 ball valves where the line devides? If so the 1to the circuit should be closed and the other opened. The reason for this set-up is so you can use attachments that require 2 way oil flow, hammers only require 1 way flow.
If there is no ball valves disconnect the circuit line and plug and cap them. See how you go.

 

[YAHYA]

I take it that there only 2 lines connected to the hammer. Are there 2 ball valves where the line devides? If so the 1to the circuit should be closed and the other opened. The reason for this set-up is so you can use attachments that require 2 way oil flow, hammers only require 1 way flow.
If there is no ball valves disconnect the circuit line and plug and cap them. See how you go.

It's one way line from the screen in the cab.
All movements are normal.
But the hammer is so so so weak.
The hammer must take 180 to 200 bar.
The excavator give only 90 bar and its weak.

 

[Tones]

First you must ascertain that the oil flow is correct, flicking a switch may not work. I have operated excavators that required 2 pumps to run them so a priority valve was installed. I have helped set up machines for hammers and it can be experating

 

[Diesel Dave]

If you are a 100 bar low , It sounds like there is a circuit relief valve in the auxiliary section of the main valve bank that needs to be adjusted higher.

 

[YAHYA]

If you are a 100 bar low , It sounds like there is a circuit relief valve in the auxiliary section of the main valve bank that needs to be adjusted higher.

The settings in screen is 200 bar. And i rise it to 250 bar. And it was useless.
If the filter is closed, does it cause weakness in the hammer?

 

[Diesel Dave]

A plugged filter will raise the back pressure on the return side.
I find it hard to believe that the machine has the capability to raise the pressure available in the hammer circuit from the machine monitor.
If I understand correctly ,you said the hammer must take 180 to 200 bar to run.
I would suggest putting a guage at the hammer inlet and check the hammer operating pressure.
Then plug the hammer inlet hose and see what the relief pressure is at.

 

[92U 3406]

Are you setting the relief to the hammer's operating pressure or setting it higher? Check the hammer's operating manual, it usually lists a relief valve setting, typically about 750-800 PSI higher than operating pressure. If its set at operating pressure you are constantly running the unit over relief.

Never trust that in-cab display, they are whack well over 90% of the time. Get a flow meter on the aux circuit to verify proper pressure/flow to hammer.