Hi good person,I have a poclain MSE 02 wheel motor in my xt855 ditch witch track machine. The oil seal keeps blowing out releasing oil out the drive shaft of the motor. The motor failed creating some metal fragments in the system and has being repaired but keeps blowing the oil seal. Any help would be greatly appreciated. Thanks oka
If by fixing means the shaft seal was replaced is only fixing the symptom and not the cause. Worn hydraulic motor parts cause an increase in casedrain pressure which blows the seal. A simple check you can do is to measure the casedrain oil flow. to do this, have the wheel stalled, remove the casedrain hose/pipe from the motor and place the end into a bucket. run the machine for 1 min at WOT with the drive motor activated then shut the machine down. Measure the amount of oil. any more that 2 litres indicates wear in the motor.
Thanks Tones that makes a lot of sense don’t mind doing a job once but not three times. I’ll do as requested and try and inspect drain line back to tank.The drain line from each motor joins into one the goes to hydraulic tank only one motor does its seal.just wondering if some metal fragments got stuck in drain line when it first failed. The motor has new pistons rotor and cam now apparently original cause of failure was due to cavitation. Appreciate your help thanks so much. PS the motor has a hydraulic release park brake as well and the machine hasn’t even got 400 hours on clock original. Once again thanks Ocka
Is there a filter anywhere on the casedrain line and was it replaced after the repair? If not change it and cut the old one open and inspect. The flow test I mentioned should be done as close to the motor as possible and will give some sort of benchmark to work from if nothing else. The park break requires pressure to release (usually about 600psi) and if its operating correctly shouldn't be of concern. Do you know what caused the cavitation and has that been addressed? Was the repaired motor filled with oil prior to startup? Last question, who repaired the motor?
Thanks for your questions,there isn’t any filter on the vent line from the motor to tank .the cavitation apparently caused by a negative load on the motor like it was dragging not applying positive power. The motor was charged up with oil before start up .the motor was repaired in our own work shop not taken to a hydraulic repair shop. Thanks for those specs good to speak to someone who knows there stuff regards Ocka haven’t had a chance to do drain test yet.
Group drive hydraulics
Been doin some thinking on this. Re the cavitation. Has the operator been cutting the engine revs while working on a slope so as to gain speed as in freewheeling? That will be were the cavitation is being caused with the hydraulic motor becoming a pump with insufficient oil being fed to it. No hydraulic motor will take that abuse for long. Hydrostatic systems require 100% engine revs 100% of time. So the first and second failure maybe directly related. Check both drive motors for casedrain flow because they are connected via the hoses and the other motor could be pressurizing thats blowing seals.
Thanks tones it’s annoying me as well glad you know your stuff a bit of a puzzle but good point about the other motor noticed the third smaller hose on the diagram with hoses to motor goes to the charge manifold not really sure what is meant by this must be the line that supplies pressure to release brake. There’s being plenty of times where the operator hasn’t operated the engine at 100% revs maybe a point. Great to have your help as I live an hour from any town on a sheep property in central NSW Australia getting help out here is difficult.just a bit busy doing doing some sheep work haven’t had a chance to do the tests just yet.
We're is your nearest big smoke?
200 kms west of Dubbo is probably the closest big gig but 85 kms from Nyngan which is smaller with the basics
PM sent.
Hi tones are u out there the shop couldn’t shed any new light on the situation we where talking about with ditch witch unfortunately didn’t keep your number for the update.thanks Ocka (dave)
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