Oil & Fuel 2008 Foton 254 loud hydraulic bypass noise

[D0TC0M]

I got to use the tractor today to blow snow and noticed the hydraulics making a loud bypassing noise. I used a stethoscope to listen where the noise was coming from and it seems to be the loudest at the splitter block. Can someone shed some light on what the cause is because its really loud when your at high RPMs. The noise only happens when the front steering is not under load. As soon as I turn the steering the noise stops. I made a small video to illustrate the problem

 

[jacques54]

Hi,
The route of hydraulic oil is normally and without FEL is: pump to diverter valve and three point. First you should check the Quick disconnect under the tractor for partially blockage that are known for that. On my FT 254 I bought it from a hydraulic shop and they replace them at PDI before I own it. In the same time you should try inspect and clean the priority valve above the starter on right side. This valve close the flow to the rear to let turn the wheels first (noise stop). My guess is your implement raise by the pressure relief in it instead of the flow control in it too.

I have a noise in my tractor too but from clutch or transmission. (Check You Tube in "Foton 254 weird noise".

I really like if my pedal come from under the dash board like the TE instead of the floor. It would make the floor simpler when I made my plywood cab.

Jacques

 

[RonMar]

Yep, clean the diverter valve. It's purpose is to give flow priority to the steering over the 3PH operation, so if you are lifting something with the 3PH and turn the wheel, the lift will stop untill you stop turning the wheel. Since it stops making the noise when you use the steering, it sounds as if one of the small ports is partially clogged. The diverter valve piston has some small ports inside it. It is easy to work on, just unscrew the large plug/cap with a wrench and you should be able to pull out the piston with a pickup magnet(magnet on a stick).

 

[D0TC0M]

Is this what you call a diverter valve? And will there be a lot of oil in there? If that is the part in the picture that your talking about, where is the large cap/plug?

 

[RonMar]

Yep, that's it. On the end of the round part where the ID tag is rivited you should see the flats on the screw-in plug. You might leak a little oil but it shouldn't be too bad...

 

[D0TC0M]

I have a noise in my tractor too but from clutch or transmission. (Check You Tube in "Foton 254 weird noise".

I just found your video. It doesn't sound good. I'm not familiar enough with the construction of the dual stage clutch to tell for sure. Its funny that the noise only starts after pressing about 1/2 way on the clutch pedal. If it was the throwout bearing you would think it would make noise as soon as you press the pedal.

 

[jacques54]

Hi,
Exactly what I am thinking.
If it is the TOB, the noise should be from the moment it touch the clutch fingers all the way to the bottom of travel. This is with or without PTO engage. It sound like my old Black & Decker drill with worn bushings.
I think it is the two input shaft are wobbling in each other.

I will split the tractor before next winter, hoping to find something unless it broke before.

Jacques

 

[D0TC0M]

Yeah me too I'm going to take the cab off and go through everything step by step later this summer. I just noticed one of the 3 hydraulic levers is leaking oil and its in a really tight spot so I will take the cab off and go through every thing a to z. I want to go through all the linkages and inspect everything that I can reasonably can. My dad bought this tractor new and did absolutely no maintenance to it. Good thing is mecanically its still really good and it only has 350 hrs.

 

[RonMar]

check EVERY nut and bolt! Chinese threads being what they are, they tend to work loose. If it has had no maintenance, you may find some of the serious stuff has worked loose, like the big nut on the end of the hydraulic steering cylinder under that rubber boot Also don't forget the lug nuts, no fun when the wheels fall off...

 

[D0TC0M]

Ok I thought I fixed the noise but after the oil warms up the diverter valve (above the starter) progressively bypasses more and more the hotter the oil gets. When cold it works perfect but after 10-15minutes under load the bypassing noise is fairly loud. Ideas?