WA 500-8 Hydrualic oil filling Transmission

I am currently repairing a 2016 WA500-8. This machine has just over 11,000hrs on it, and is now puking hydraulic oil into the transmission. I have done the repair to a older model 2007 WA500-6 multiple(3) times. It has currently 23,000+hrs on it. It has been the implement pump every time. Now the newer model is doing the same thing. I have a few questions. ( #1 ) Is there any solution to this failure? ( #2 ) is this expected on these machines with these kind of hours? And its one b*tch of a job!. Implement pump and Steering pump can be accessed by just removing cab only. The other two pumps need tank removed as well. ( #3 ) is there any way to access the bottom bolts on implement pump?

Are they still using the aluminum bodied gear pumps or have they finally started using the piston pumps. The aluminum pumps were only good for around 5,000 hours and yes it was always hell to R & R the pumps.

Yes all our machines are still using aluminum gear pumps. Im finding the implement pump shaft seal failing regularly. Im curious what fails the seals. Is it the oil we use or the amount of heat at that seal? We did replace implement pump on the older model 2 seasons ago. Still failed under 1000hrs after.

did you look at the seal area of the shaft close

The aluminum bodies swell and contract with the hydraulic spikes when running the bucket and boom. Topping out and snapping the bucket back against the stops make for spikes that the reliefs aren't fast enough to catch. I was told by a Komatsu rep that aluminum doesn't work harden. It only takes a finite number of cycles and then doesn't return to its original shape. I think he called it modulus of elasticity.

Both machines run a steel piston pump. So only case drain pressure at shaft seal. The only aluminum gear pumps are the one piggy backing of the steering piston pump I believe

Sounds like you are beyond my time working on these. I had heard of them going to piston pumps but hadn't seen that happen in my time working on them. I'm guessing that the case drains on the shaft seals drop back into the suction side of the pump casing? What about the breather on the hydraulic tank itself. It has a filter in the top of the breather valve and it might get plugged to allow over pressuring the hydraulic tank. The tank usually charges up to around 15 PSI of air pressure on top of the fluid to make sure the pumps are supplied with oil.

BigNorthTech said: Yes all our machines are still using aluminum gear pumps. Im finding the implement pump shaft seal failing regularly. Im curious what fails the seals. Is it the oil we use or the amount of heat at that seal? We did replace implement pump on the older model 2 seasons ago. Still failed under 1000hrs after. Click to expand... If it is any consulation the Cat 980H loaders have a long set of pumps all hooked together, and most were steel gear pumps and was a cab off job also. Was involved in one of these jobs and best was to change the whole thing in one shot. And yes dead ending the cylinders any time does cause spikes that eventually have to be paid for in hoses or pumps or control valves. Simon C

Pull the ground drive emergency steer pump off the front of the trans and do that first, otherwise rip and cab and tank and do the work equipment, fan and steer pumps, split the torque converter and trans pumps and reseal the orings between that and the steering pump and do the brake cooling pump seals at the same time and the orings around the outside of the fan and work equipment pump case seals. Have fun, not too bad of a job, order new suctions hose, pto metal lube pipe/tube and there's a couple small hoses under the tank and reseal under the tank whilst in there

Have any of you guys had machines with (Certified Inc) Oils in system?