Knivens894
Well-Known Member
I have owned this machine for more than 10 years. In the summer it has had a hydraulic overheating problem. I have spent a lot of time and money trying to find the problem. The list of the efforts is too long to post here. The hydraulic system was hot everywhere when tested with a thermal gun. I gave up on the search and installed a electric booster fan in front of the radiator a couple of years ago. The machine's performance was jerky, so I always ran it in the fine grading mode, and adjusted the DP sensor up to slow down its response.
Last week it burned up the coil on the hydraulic pump high pressure solenoid and failed a couple of fuses in the process, so I decided to go through all of the adjustments controlling the main pump pressure through the computer. I first replaced the high pressure solenoid. The angle sensor was out of spec, but I had another on hand and just replaced it. The differential pressure sensor was also out of spec (read 0.65 on removal), so I adjusted it back to the 1.7 where I had been using it to reduce the jerkiness. As I moved it back toward the installation position, the reading on the sensor changed on the volt meter. My initial thought was the wiring harness might be defective, so I moved the harness around looking for a voltage change. There was none, yet when I moved the sensor itself, the voltage varied wildly, going both up and down. I ordered another DP sensor and cut the old one open to see if it had a broken wire internally. It did not.
Yesterday I installed the new DP sensor, adjusted to 1.7 as I had the other, and the hydraulics would hardly function. Then I moved it to the current factory recommendation of 1.45 and functions returned. I ran the machine all yesterday afternoon in a heat index of 112F, and the heat gauge on the machine stayed at about 2/3's the green range. I have not seen that low a temperature in many years. It has normally been up next to red.
I have to conclude the DP sensor was defective internally and has caused the overheating problem with this machine for years. The varying signal from the DP sensor was calling for pressure from the pump which caused both the jerky performance and the years of overheating all the hydraulic system. It over worked the high pressure solenoid, which caused its failure. Several others have contacted me over the years about overheating of my machine and how I solved it. The booster fan simply treated a symptom. The old DP sensor would take an adjustment setting, which lead me to think it was good, but something inside of it made the output vary in service. If you are having jerky performance and hydraulic overheating, the new DP sensor solved my problem. HALLELUJAH!! and HALLELUJAH!!
Last week it burned up the coil on the hydraulic pump high pressure solenoid and failed a couple of fuses in the process, so I decided to go through all of the adjustments controlling the main pump pressure through the computer. I first replaced the high pressure solenoid. The angle sensor was out of spec, but I had another on hand and just replaced it. The differential pressure sensor was also out of spec (read 0.65 on removal), so I adjusted it back to the 1.7 where I had been using it to reduce the jerkiness. As I moved it back toward the installation position, the reading on the sensor changed on the volt meter. My initial thought was the wiring harness might be defective, so I moved the harness around looking for a voltage change. There was none, yet when I moved the sensor itself, the voltage varied wildly, going both up and down. I ordered another DP sensor and cut the old one open to see if it had a broken wire internally. It did not.
Yesterday I installed the new DP sensor, adjusted to 1.7 as I had the other, and the hydraulics would hardly function. Then I moved it to the current factory recommendation of 1.45 and functions returned. I ran the machine all yesterday afternoon in a heat index of 112F, and the heat gauge on the machine stayed at about 2/3's the green range. I have not seen that low a temperature in many years. It has normally been up next to red.
I have to conclude the DP sensor was defective internally and has caused the overheating problem with this machine for years. The varying signal from the DP sensor was calling for pressure from the pump which caused both the jerky performance and the years of overheating all the hydraulic system. It over worked the high pressure solenoid, which caused its failure. Several others have contacted me over the years about overheating of my machine and how I solved it. The booster fan simply treated a symptom. The old DP sensor would take an adjustment setting, which lead me to think it was good, but something inside of it made the output vary in service. If you are having jerky performance and hydraulic overheating, the new DP sensor solved my problem. HALLELUJAH!! and HALLELUJAH!!
