E.S.M.E is the Edinburgh Society of Model Engineers and we have bought 11 acres of woodland outside Edinburgh to build a centre where engineering skills can be passed on, and where members and visitors can enjoy our proposed miniature railway with at least 3 gauges, boating pond, rc car racing and picknicking. To build this, we bought a EX60URG excavator which worked well for a time until the seals burst on a traction motor followed by loss of power to one side of the unit. A rough sequence of events over 8 months is as follows. 1: Uchida pump removed and sent to repairer who gave a quote for repair which we could not consider, then returned it to us dismantled, in a dirty box, with the undamaged parts missing. The damaged pistons, shattered piston ring, swash plate and other parts from one half of the pump were returned. The club purchased all the necessary parts and I rebuilt it. 2: The pump was refitted to the excavator and everything worked except there was no power to the blade, and the swivel brake would not come off. Removal of the pilot filter, which was clogged with what appeared to be a jelly like material, resulted in the swivel brake coming off and the cab would turn. The blade moved very slowly with practically no force. 3: The unit was driven to another part of the yard awaiting filters and transport. 4: The unit was driven toward a shed for filters to be fitted but failed totally after about 20 yards. After an hour the unit was restarted and enough power was achieved to allow some movement, and it failed again. A further hour later when the engine was restarted, power was generated long enough to straighten up the boom. 5: Filters were changed and cleaned and the unit restarted. Bucket swivel, front boom, side boom work but with unknown power. Main boom will lift a little at a time if the lever is jagged. Travel wants to move when jagged but brakes are not coming off. Blade does not work and unit will not swivel. During all this there is no change in the sound of the engine, and there is plenty of turbulence in the tank. I have considered that a) Pressure relief valve(s) may be jammed open or b) Pilot pumps may be damaged Can anyone help? Can relief valves be tested and where are they? Does anyone have the cicuit schematic for the hydraulic system which appears to have 2 pilot pumps? I am working with the manual for EX60-1 GeorgeP
If you can post pictures it would be a great help. What happened to the old pump? Major failure? How was the system cleaned??? Im assuming this is just a regular pressure compensated pump with a 3/4" BSP ports? You can start by dead heading the main working sections of the pump. Then you can work your way down the line. Do not dead head the gear pump for the pilot system!
Sorry for the delay in replying. The old pump suffered a catastrophic failure when the ring supporting the pistons broke. Dead heading made no impact on the functions of any of the sections of the pump. Since my first post I have received a parts manual for the URG variant and am constructing a circuit diagram for the unit from this. Today I had the benefit of the experience and equipment of a field support engineer who eventually established that the main pressure relief valve was open. He removed the valve. flushed it through and reset the pressure. All functions of the excavator have now returned except the blade operation which has a faulty gear pump. Anyone know where I can enquire about a new pump in UK? Thank you for your interest.
Thanks for the follow up