HELP ex 120-3 oil cooler and water radiator cleaned and in fair good shape, constant stong hiss (like oil passing) from valve chest. Pilot pump has a stong hard pulse every few seconds, machine goin well but a bit jumpy. no heat problems when idleing, hyd oil very hot after 20 minutes work can any man help
My JCB 220 is doing the same thing. Can’t figure out what is causing the excess heat. Heat exchanger (oil radiator) tests 30 degrees hotter at the top than at the bottom so it appears to be properly cooling the oil, but still gets too hot in just a few minutes of working. Fan also appears to be working well. I’m wondering if there is a hydraulic oil thermostat???
Not a thread hijack. A 30 degree delta T across the cooler is way to much. Should be 6-8 maybe. There is a restriction. Janky hydraulic hose, contamination, some sort of valve malfunctioning. We need to look at a hydraulic schematic. In the meantime, danny d is running hot. The Hitachi is hot and tempers are flaring up on the job site. I’ll be back. DaltonB has hay in the field and we have to get it under cover before the rain.
The pulse is from the pump control solenoids. They pulse every few seconds when they are making adjustments to the pump angle. If the oil is cold you can't really hear or feel them. As it warms up it becomes more noticeable. My machine does it and from the other threads I have read it is considered normal. If somebody knows better please enlighten me.
Thanks Coaldust. Frank
thanks for the replys men,will let use know if i get her sorted
The fan might be slipping. The v belts may be hard to see. They may be oil soaked and nasty. What is the temperature in your AO? Unseasonably warm? Take some pictures of the coolers/radiator.
Yes, it is hot here. Upper 90’s and high humidity, but this overheating issue is new. Radiator is clean and free of debris. Have not checked the belt yet, but engine temp is staying good like always. Will do more checking tomorrow. Thanks a bunch!
At those temps, everything needs to be perfect. Did you install all the plastic and rubber shields after the radiator and cooler was cleaned? All that crap has to be there or the air takes the path of least resistance. Read through this old thread. This EX100 had a pilot pump issue. Which explains why your machine is acting jumpy. Your main pumps could be reacting to the change of pilot flow/pressure. HeavyEquipmentForums
thanks for that is it normal for the strong hissing noise coming from the valve chest even when machine is idle
I’m not familiar enough to answer that. Maybe. Sounds like it’s time to perform some testing. Check pilot pressure. Maybe the pilot relief is stuck open and that’s creating the hiss. Does it have a pilot filter? Maybe the pilot pump defecated the bed like Amber Heard did.
aye it has a filter straight after pump i am goin to change that next and i will take a few pressure readings and get bak to use thanks for ur time
Don’t just change it. Access the filter media and see what’s inside. If it’s full of metal, we have a problem. You are welcome. I’m a old, cynical, ugly, grouchy *******, but I sincerely try to help. Ability to fix stuff and get people out of tough jams is my only redeeming quality.
ahhh!!!! please god i dont find metal anywhere
now googlin symptoms of a bad pilot pump dosent make good reading, any man lookin a gud 120-3
From what you have described here. It sounds like your hydraulic system is going over relief continually. That would be the hissing noise that you are hearing from the main control valve.
mmmm id does sound like oil passing alrite, ill have a look at weekend to see if it looks like its been tampered with. in my limited knowledge i wud have thought the oil wud have a no restiction through the chest until a lever wud be activated and only after that the relief valves wud come into play
Unlikely tampered with. More like a small piece of contamination jamming a relief valve open.
thanks men