Wondering if anyone has ever had this issue... the hydraulic pump sounds just fine when either a cylinder or hydraulic motor is activated but when neither is activated the pump makes a bad noise and the suction hose vibrates? I'm of course baffled. Any ideas?
Hydraulic Pump Noise... but not always.
- Thread starter RDSmith
- Start date
- Views: 9957
K5lwq
Elite Member
- Joined
- Aug 6, 2017
- Messages
- 4,818
- Location
- Mineola, TX
- Tractor
- Kioti LK2554, Branson 4815C, Satoh Beaver, Speedex
Pump cavitation due to sucking air would be my first thought.
Leejohn
Elite Member
Change your filter and check the pickup screen if it has one.
oldnslo
Super Member
RD
What make and model of tractor is this?
does the pump make noise when the cylinder hits end stroke so pump is going over relief?
Is the 3 Point lever pulled all the way? Maybe try lowering 3 point a little.
just wondering if something changed so the pump is going over relief which can make noise and might cause some vibration depending on where relief is located
What make and model of tractor is this?
does the pump make noise when the cylinder hits end stroke so pump is going over relief?
Is the 3 Point lever pulled all the way? Maybe try lowering 3 point a little.
just wondering if something changed so the pump is going over relief which can make noise and might cause some vibration depending on where relief is located
I bought an old no longer manufactured saw mill that had sat around for several years and needed most of the hydraulic hoses replaced. The hydraulic pump wasn't there and so I had to purchase that. I have to admit there was some guessing here. I'm only used to hearing the hydraulics on Farmall tractors... not used to the pump noise I am referring to.
Just maybe/probably I don't know what I'm doing. The unit has a pressure gauge at the end of one of the two control spools. When I have one of the hydraulic motors activated (idle engine speed 1000 rpm) the pressure is about 400 psi and when nothing is activated the pressure reads about 1600 psi (assuming gauge is accurate). Is this about what it should be? I guess I assumed the pressure would be closer to zero when nothing was activated. Wrong? Just assumed the fluid would flow freely through the control spools and back to the reservoir. Wrong?
Or do I need to install a pressure relief valve into the system?
Just maybe/probably I don't know what I'm doing. The unit has a pressure gauge at the end of one of the two control spools. When I have one of the hydraulic motors activated (idle engine speed 1000 rpm) the pressure is about 400 psi and when nothing is activated the pressure reads about 1600 psi (assuming gauge is accurate). Is this about what it should be? I guess I assumed the pressure would be closer to zero when nothing was activated. Wrong? Just assumed the fluid would flow freely through the control spools and back to the reservoir. Wrong?
Or do I need to install a pressure relief valve into the system?
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oldnslo
Super Member
RD,
depends on what type of valves are on the saw mill. If closed center which are used for variable volume pumps and you have installed a gear pump then the pressure would go to relief setting anytime the valves are centered.
Are there any nameplates or model codes on the valve stacks? Are there any labels or markings by the ports on the valve? I.e. P or In for pressure, T or out for tank, etc.
depends on what type of valves are on the saw mill. If closed center which are used for variable volume pumps and you have installed a gear pump then the pressure would go to relief setting anytime the valves are centered.
Are there any nameplates or model codes on the valve stacks? Are there any labels or markings by the ports on the valve? I.e. P or In for pressure, T or out for tank, etc.
If I understand it correctly the double acting control valves (two sets of 6 spools) are open center? As I said early I just assumed the oil would just flow through without any restriction when the control lever was in the middle position. Maybe I have that wrong? Or is a relief valve a part of the valve sets?
I doubt where the valves are I could see any labels or markings on the valves but I'll try looking.
I doubt where the valves are I could see any labels or markings on the valves but I'll try looking.
oldnslo
Super Member
Rd
Lets try and attack this problem from a different direction. How many hoses or lines are connected to each valve bank not counting the lines going to cylinders? Are there 2, 3 more? These should be pressure, tank, and if open center a power beyond on at least one of the valve stacks.
Lets try and attack this problem from a different direction. How many hoses or lines are connected to each valve bank not counting the lines going to cylinders? Are there 2, 3 more? These should be pressure, tank, and if open center a power beyond on at least one of the valve stacks.
Thank you everyone who is putting up with me. I can't answer that last question today I guess. I really don't understand what is meant by "a power beyond". And maybe it's cavitation like some have suggested too? "Cavitation occurs when the volume of fluid demanded by any part of a hydraulic circuit exceeds the volume of fluid being supplied. This causes the absolute pressure in that part of the circuit to fall below the vapor pressure of the hydraulic fluid. This will result in the formation of gas bubbles." I guess I assumed that things just happened slower if the supply was less? If "supply" is the fluid after the pump.
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PILOON
Super Star Member
Perhaps a pressure relief valve related, 'vibrating' or 'fluttering', since you say when "when nothing being activated".
