First off, I apologize for not posting for a while.
These past few weeks of working through hydraulics have been extremely educational! I went trough several boxes of pipe fittings and hose fittings trying my best to identify them. Though, I still could use some more practice. Our class rented a Bobcat E32 Excavator, we have been going through the service manual and looking over the hydraulics schematics which has been pretty great! I have learned a lot by having the machine here to match symbols on the schematic with the parts on the machine. I had trouble with finding out what a certain hose was that was just hanging off the side of the machine, it wasn't on the schematic but after some digging into the service manaul (and a few hints from Jeff) I soon realized that this elusive hose was clearly the drain hose. Oh well, we all have our moments right?
We were assigned into groups to isolate certain hydraulic circuits in the schematic and find them in the machine and explain to the class how it opperated. My group chose the pilot system. We found the opperating pressure of the oil in the service manual and tested it at the test point located on the manifold of the pilot system. Our results ranged from 415-450psi depending on what the engine speed was set to (turtle mode, and rabbit mode.)
For the hydraulic final, we needed to find what the service manual said about the cycle times of the functions like boom raise, bucket curl, blade lift, etc. I chose to do bucket curl. In the sevice manual it states that the cycle time for the bucket curl is 2.7 seconds, when I tested it the time turned out to be 2.3 seconds. I am not sure as to why it was faster then specified in the manual. I will include a video of this test in this post.
Another part of the final was to prove speed of the tracks by counting the number of revolutions made in one minute. The service manual states that the tracks move at 2.9 mph which equates to about 17.7 revolutions per minute have a track length of 14.416ft. When we ran the test we counted the revolutions per minute and we got 19 which equates to 3.1mph. I think if was faster than specified because there wasn't any load on the tracks, we had the tracks lifted up on one side.
We recieved a worksheet that asked the question if we could complete oil flow test sheet for the Bobcat with the same meter we used testing the flow on the winch and windlass from the boat. my answer is, no we couldn't because one of the tests required a gauge that could handle 345 bar and 5000psi. The flow meter we had only goes up to 240 bar and 3000psi.
We will be moving on to preventative maintenance now before the end of the quater. I think it will go over how to keep your equipment in good working order for as long as possible. With that in mind, I should probably go change the oil in my car...
Total Hours: 185
