Today we blew the main hydraulic line that goes from hydraulic tank to the pump. Machine is a 963A 21Z serial number. The machine from the time it blew the line and unloaded the oil was shut off within a minute or so when operator noticed oil pouring out. After we fixed the line (which is a PITA because of that stupid clamp bracket that mounts to the inside of the frame) and I filled the machine back up with oil. The boom raise and lower/bucket functions are really slow and will not pickup a bucket of dirt. Any suggestions of what to check? Thanks in advance
pump is probably damaged from running out of oil
Well a quick check on SIS shows the main hydraulic pump running at an engine speed of 1,100 rpm and working at 1,000 psi would be putting out 19 gallons a minute. At 100 psi it would be 21 gallons a minute. As the tank capacity is only 15.9 gallons if it ran for "a minute or so" leaking it would have been running dry for some time. My money is the pump has wiped out the trust plates in that gear pump. And as for that "stupid clamp bracket" that probably is the reason the line did not fail many years ago! I agree hold downs can be a pain to remove and replace but they are there to protect the hose from damage.
Not sure that the machine ran for a minute could be less. But after running the boom up and down with the new line and oil in it for like 10+ minutes it now runs and works fine. Pulled hydraulic filters to check for metal fines or collapsed filter. After put filters back in and ran it up and down for a little bit worked good. I don't think its possible to get air in the system is it?
I think any hydraulic system can get air in it if there's a leak or it runs low on oil.
Yes and some take a bit longer than others to work it all out.
Aboslutely possible to get air in the system. Did you cut the filter open to check for metal particles in the base of the pleats of the filter media..? If not I think it's highly unlikely that you would have seen anything. The usual method is to cut out a section of the filter media, squeeze it in a vice to get the oil out, the pull it open and go looking in the bottom of the pleats for visible particles. If you don't see anything, go looking with a magnet, you might be surprised by what it picks up.
Here's a good "how to" video on cutting oil filters. I know the video shows an engine oil filter but the theory is the same for all filters.