Was leveling the other day on my Taki TB-135 and heard the dreaded sound of a pistol shot. It took a second to figure out it was the auxillary circuit, which I do not recall hitting and have never had anything attached to this circuit. Is this circuit always slightly pressurized or do I need to look for a slightly open valve, however I hear no bogging of the engine indicating a substantial feed to this. Thanks, fellas. I hope to hear some feedback.
I must admit I have no explanation. All hoses on cylinder, including aux circuit, has some pressure on it when engine is running, whether from valve leakage or from anti-cavitation valves of circuit, but unusual to be enough pressure to pop a hose unless circuit was activated. Total mystery to me.
I had the same thing happen with my New Holland backhoe. As I drove out of the shop one day, the hose for the aux blew. I didn't hear a thing, but hosed down my trailer the side of the building, wiht a nice stream of oil. It was very cold outside so I backed back into the shop giving everything a second coat of oil. I bought two caps removed al the wtuff I never use and capped them off.
Same thing happened to me last spring on a pool deck demo job with a rented tak 219. I wasn't using the hammer at the time. The aux hose just let go. I had to scramble to put down plastic to protect the stone work that was to be kept.
We were thinking of buying a mini excavator and yes we rented different ones to try the size/mfg etc. I recall one machine had around 2k hours, the tracks were getting kind of worn on the inside (outside looked fair) and the track had jumped off once so they sent a mechanic who pried it right back on. One afternoon, it started making random popping / thumping sounds like maybe a hydraulic relief valve was lifting...the operation was perfect....we looked at the hydraulic system and didn't recognize one part or item, nor was there any apparent problem like a leak or a crimp/kink...the rental yard said to keep running it and thanks for calling to let 'em know...A couple days later we called it off rent - job done. We stopped by the rental yard office a week or so later and inquired what was the problem? The counter man spun the computer terminal around and said here is your answer: "Machine Sold at Auction Sale". He said these 'strange' problems at that level of hours are sometimes like chasing a very expensive tail, and what with the tracks and the hours telling them to replace same, they figured the machine had duly earned its keep. That was a good lesson for us as we now wonder how we would deal with such an issue were we to be the owner. The complexity isn't helping as to these consequences of oil leaks and I fear what would happen if the machine was idling and it was being greased and a hose burst: would it injure the mechanic? ** Could it be possible some type of pressure regulator had allowed the pressure in a non flowing circuit to rise up? This is common for houses where the city water pressure is too high for the limit of house piping, the faucets and the toilet (water closet) valves etc, so a pressure regulator at the connection point is installed. Initially the regulator valve seat is good and with no flow, the pressure is maintained @ "reduced". As the valve seat wears, the pressure creeps up and faucets and hoses etc start to blow off (fail). If one gages it, if there is any flow, the pressure is maintained in the safe range. As soon as there is no usage of any water, the pressure creeps right up to equal the main pressure. In this situation the regulator is not accomplishing much. The building (home) owner has no indicator of this condition until the big flood. * Maybe have to get a gage. I imagine the dead ended (no attachment) aux circuit could inadvertently see high pressure every time the system goes up to the circuit relief if a control valve was leaking....other circuits could be in the same condition, but most the time the ram would move ever so slightly and relieve it. As to the pilot circuit pressure system, I figured the operator would detect this being too high but maybe not....the designer could put a bleed port on the circuit to require a minutia of flow which maybe would help with regulation, but I am just guessing...probably have to put a gage and check it.
Thank you for all the replies. Well.. now that I know others have experienced similar gremlins I will just replace the hose and not worry too much about it. I am pondering and wonder if you could cross or tie aux together to releive pressure. Or do you accomplish the same by moving the valve on the house to hammer.? like I said I never have messed with the aux. I do recall after the burst there was a steady small flow of oil and it stopped when I shut the engine, I restarted engine the small flow started again. I did this to make sure it was not just gravity drain.
Even if there was pressure leakage the hoses should be rated high enough to withstand the pressure generated by the system. Sure eventually they get old but a good condition hose with the proper rating should not just go pop. Perhaps take the caps off the aux hydraulics and start the machine.
I think it's just one of those things...i've had a hose on a brand New Volvo Grader let go without warning, had no contact with anything else whatsoever, The machine was stationary with no operator and all of a sudden it burst. I think maybe the AUX systems get alot of punishment because of ROCKBREAKERS etc with the constant pulsing etc perhaps.
It sure is one of them acts of nature how all grades of rubber hoses fail... and rubber in general, a similar situation happened to my truck tire. I had just finished driving my truck on the Interstate having just gone 85 MPH, so I parked it for Two minutes then rolled it forward about 4 feet to load it and then all of a sudden a loud hiss began blowing out the "Side Wall"... I looked and seen it was dry rotted.... I still wonder why didn't it blow when I was going 85 MPH ?? but rather decided to pop a leak shortly after not under any load? almost like what your hose did...?
The short answer to that is the tyre is no longer being cooled while rotating, so when it's stationary the heat really takes hold.
It is interesting to hear all the different but somewhat similar instances from others. Seems we all have seen it at some point or another. And sometimes it helps to hear advice and knowledge from others to reinforce your own back burner gut feelings. Thank you for all the replies.
Had a hose let go on my old Hein Werner C12HD the other day, it was on the rod end side of the main boom cylinders while the boom was up in the air, shouldn't have been much if any pressure on that side... Granted the hose was probably as old as the machine but I jacked the machine up with the boom a few times and nothing let go then, just out of the blue while I was swinging it, POW, and a new coat of rust proofing was applied to the machine...