Put this in the general area it is a pretty generic hydraulic issue.
Dealing with a Yale 9K forklift that has not been run in years due to a bad engine. We replaced the engine but before even finishing the engine, I noted a small leak coming from the main rubber suction hose from hydro tank to the main gear pump. It is about a 2" hose. The original one appears to have simply cracked from age, however, there was still about a 1/3 tank of fluid.
We test fired the machine briefly to confirm reasonable operation and all functions were normal. We lifted the mast just a little to confirm valves worked. After that, the hydro tank was drained, suction line replaced, and removed oil put back in the system as it was clean, and we added another 10gal of new AW46 over that.
So far the fork has run 1-2hrs total while testing and adjusting things. There are no more visible hydraulic leaks on the suction line. However, there is a little more whine to the main pump than I would prefer, and there is very certainly odd noise coming from the steering booster on the column. Things that are telling me I might have some more issues in the hydraulic system.
I don't know precisely how the inside of the tank is configured because we removed the oil by drilling a hole in the old suction line, draining, and adding it back. However, the parts book indicates a screen filter on the suction side, then a proper hydraulic filter in the tank on the return oil line.
There is no visible aeration on the dipstick while running, and the suction hose has not acted like it is trying to collapse, indicating a restriction. The hydraulic power of the machine was tested to near full capacity and it certainly has power to waste. Cycle times are also normal, steering is normal, etc. Just noise.
I am looking for some troubleshoot ideas to source the issue. I am a little baffled. I know hydraulic pumps can make a little noise but in my experience, forklifts are usually very quiet and I would say the pump noise stands out a bit over the engine. As for the noise around the steering booster, if I operate the brake or turn the steering a little, it will get quieter and I would say it makes the most noise when not under load.
Dealing with a Yale 9K forklift that has not been run in years due to a bad engine. We replaced the engine but before even finishing the engine, I noted a small leak coming from the main rubber suction hose from hydro tank to the main gear pump. It is about a 2" hose. The original one appears to have simply cracked from age, however, there was still about a 1/3 tank of fluid.
We test fired the machine briefly to confirm reasonable operation and all functions were normal. We lifted the mast just a little to confirm valves worked. After that, the hydro tank was drained, suction line replaced, and removed oil put back in the system as it was clean, and we added another 10gal of new AW46 over that.
So far the fork has run 1-2hrs total while testing and adjusting things. There are no more visible hydraulic leaks on the suction line. However, there is a little more whine to the main pump than I would prefer, and there is very certainly odd noise coming from the steering booster on the column. Things that are telling me I might have some more issues in the hydraulic system.
I don't know precisely how the inside of the tank is configured because we removed the oil by drilling a hole in the old suction line, draining, and adding it back. However, the parts book indicates a screen filter on the suction side, then a proper hydraulic filter in the tank on the return oil line.
There is no visible aeration on the dipstick while running, and the suction hose has not acted like it is trying to collapse, indicating a restriction. The hydraulic power of the machine was tested to near full capacity and it certainly has power to waste. Cycle times are also normal, steering is normal, etc. Just noise.
I am looking for some troubleshoot ideas to source the issue. I am a little baffled. I know hydraulic pumps can make a little noise but in my experience, forklifts are usually very quiet and I would say the pump noise stands out a bit over the engine. As for the noise around the steering booster, if I operate the brake or turn the steering a little, it will get quieter and I would say it makes the most noise when not under load.
