ronjhall
Super Star Member
After installing the new pump. Put a gage on the system to check relief valve setting. I would guess that old pump cracked from over pressure.
KubotainNH said:Chris, I can't believe you broke your tractor!!
Seems to me it cannot be connected backwards, I would think it wouldn't have worked properly but by the sounds of it you got some use before it cracked. I'd go with the dead heading on full curl.
BTW, how well did the little pump do with that loader while it worked?
One last comment, my loader barely makes the engine lose RPM when maxed out so I can't see it stalling if dead headed. Maybe this is because of the way it's attached to the engine and geared as opposed to running off the PTO.
chrisinnh said:..........There's no way that the lift cylinders reached the end of their travel, but the tip cylinders may have. If that's the case, and the relief valve was at the wrong end of things (or non-functioning), then I can see that I may have dead-headed the pump: The tip cylinders stopped accepting fluid from the lift cylinders, which would have stopped accepting fluid from the pump......Sound reasonable?..............
ccsial said:I'm still questioning the gear oil. That seems a bit heavy for hydraulic use but maybe that is OK. How cold was it?
Yes, all hoses will have a burst pressure well beyond their rating. Rating is for continuous pressure. Burst has a time element involved. Waynecountyhose would know the specifics. Id guess a 4k hose would take 8 or 10k for a few seconds- and even more for an instant. Plenty of time and pressure to pop a cast aluminum pump.rbargeron said:Yes, it does. Ordinarily a hose would be expected to be the weakest link in the system. But sometimes small bore hoses have actual burst pressures much higher than their rating. Paul (techman) is right about engine inertia being able to cause a huge spike in pressure, it would come and go so fast that you wouldn't notice a change in speed - just a "knock" when the pressure pulse broke the pump.