Demo hammer on backhoe

[cat320]

Has any one ever used one on a job ?
I rented one for today to break up a 9"+ patio that is 42 ft long by 13 ft wide. I had such a problem with it not wanting to hammer .When I fist started it went hammering fast and you could hear it pulsing even after you lifted it,but not to much later it starte not doing anything or it would start to go but real slow not the fast pace that it first did.I called the rental place and they asked me if the rpm's were up and of course I had it all the way up ,asked for a mechanic to come take a look and no onw showed up at all.I finally managed to finish it after leating it rest a few times for some reason it helped .But what a pain it took for ever to do a very simple job . :(

[BKrois]

We had a similar situation on the 3500lb hammer on the excavator we rented. It was working fine and then it got to the point where it would barely hit. It turned out the fittings at the end of the hose on the hammer got lose enough where it wasn't making a proper connection with the hammer line on the machine.

After we tightened it, it worked like new. Just a thought.

[glsahl]

Hammer's frequency is controlled by a valve in the hammer,and it's nitrogen charged accumulator.Low nitrogen pressure means the hydraulic pressure has to build longer to meet the valve's release pressure.The thumping after is usually an indication of this,or that the flow rate,feeding the hammer has changed.I've seen a bloked return line cause frequency problems,one that's been pinched,but that's rare,and easily spotted.

[what the]

The nitrogen charge is important but also is constant the problem here is hydraulic oil temp. when a machine is equipped to operate a breaker the oil cooler needs to be upgraded other wise you have to run it for 15-20 min and let it cool.

[heavylift]

threaded quik connects are a pain.... we usually put bungee cords on them...
plus there is a lever we have to switch on the boom... if you don't it does't hammer very hard

[JS580SL]

Had the nitrogen leak out on a Daewoo 175 once. Hammer would hit but very weak.

[insleyboy]

Quick disconnects can fail at any time and without warning. If nitrogen levels are correct, check or better yet change the QD"s. A few times on night time demo, I have had a hammer act really odd.....slow to stopped. I changed the Quick connect and "problem Solved". Can't tell you why, but it did!