Hydraulic noise

[SouthOnBeach]

Got 2 questions. First is kind of a general one. I’m getting a noise, like a banging/surging (kinda like water hammer in pipes) of hydraulic fluid when it’s at higher rpms. (i.e. driving or when you crank up the rpms lifting) my first thought was the pump is going. But then I was thinking maybe something in the valve body is causing it. Anyone have some ideas??? :beatsme

Second question is on a lull 644D-34. Same machine as the hydraulic noise problem. Does anyone know if you can change the hydraulic filter without draining the tank? I really don’t feel like having 33 gallons pour out when I’m not prepared to contain it all. :eek:

[Speedpup]

all Lulls I have seen the filter comes out the top of the tank so yes

[will_gurt]

Got 2 questions. First is kind of a general one. I’m getting a noise, like a banging/surging (kinda like water hammer in pipes) of hydraulic fluid when it’s at higher rpms. (i.e. driving or when you crank up the rpms lifting) my first thought was the pump is going. But then I was thinking maybe something in the valve body is causing it. Anyone have some ideas??? :beatsme

WHat you may be hearing is some form of cavitation. This can be very detrimental for your pump. Is the fluid level good? Check for leaks on both suction and pressure lines.

[Iron Horse]

You've probably fixed it by now but if you hav'nt i would say the suction line is sucking flat momentarily at full noise . I have diagnosed it before and have fixed it using reinforced suction hose .

[SouthOnBeach]

I really haven't got it fixed yet. it only does it once and a while for just a few seconds. so i'm having somewhat of a hard time tracking it down. I will keep the suction line in mind.

[Iron Horse]

If you have ever seen a lay flat water hose with a kink over a gutter hammer , it is the same type action . Get someone in the machine to make it happen while you watch the suction line .

[Johnsoils]

Does the problem go away after the machine is warmed up? If so your pump is cavitating because the oil is not flowing when it is cold. In Iowa and Minnesota, switching to a synthetic pays big dividends and saves fuel burnt on warming up the hydraulics. Read more about synthetic hydraulic fluids on my web site: **************.com

Note the cold flow capabilities of the synthetic oils. If the problem is there cold or hot, then I agree with the folks that are pointing you to a suction line restrication or collapsed suction line. Good luck, cavitation is bad on pumps and motors. Have you done an oil sample analysis to see if you have done any damage to the system?

[donsoil]

the problem sounds like aeration or cavitation, another thing to check is the suction tube inside the reservoir, I had one that cracked and broke due to vibration on a cat 988 wheel loader, it caused the hydraulics to be intermittently jerky depending on how high the boom was raised. another thing to consider is the oil return pipe going into the reservoir, if a crack or broken tube has caused it to change the designed flow it could cause an aeration problem.

[Lost_Odeassy]

sorry about posting here but do not have permission to make new threads yet

Hi guys,

I have JCB 2001 model tele handler 170-541 and this morning while on jacks loading it stopped working all of sudden, basically its not getting started and nothing is working, engine, jacks, boom.

Mechanic is saying that clutch plate is gone and nothing will work because everything is integrated

Needs some word of advance anyone else experienced similar stuff in past?

Regards, Irfan.

[Iron Horse]

If it's on an angle the tilt switch has probably sensed an unsafe condition and shut the controls down .

[Lost_Odeassy]

Thanks for quick reply it is some i know who was operating and i am not expert in it but where it tilt switch yes the machine was at angle loading the stuff, how can we re-set switch appericate guidance. thanks

[Iron Horse]

The computor will usually allow the boom to be lowered , if that's what has happened . Once down , the power to the rest of the controls will resume .

[Lost_Odeassy]

well basically the mechanic said clutch plate is gone, so he put the new one, the part cost around 800 pounds or 4500 dhs in dubai and 250 pounds for mechanic charges, around 2000 dhs in other words last month profits is almost gone, took mechanic 5 - 7 hours to repair.

[Iron Horse]

Did it fix it ?

[Lost_Odeassy]

yes it fixed it...

[pudding]

southonbeach did you sort the problem?

a blocked suction filter on a machine can cause cavitation of a pump at high rpm, so can a hose collapsing, or a releif valve problem, so can low oil

also on some hyster forklifts the pump is driven by a short double chain that is no adjustable, not saying your machine has this, but when this chain wears on these machines, they slap, this also causes a 'hammer' effect when you deadhead the machine or operate at high rpm......food for thought