Massey 35 three point linkage suddenly lost lift strength

[FordnMassey]

Hi,

I had this posted in Massey Vintage and no replies so trying here instead.

My MF35 has lost it's lift power on the three point linkage. I occurred after I was installing a diverter valve to the the external cap. The stand pipe was lifted clear when the external cap was removed, so I replaced the o-rings (Sparex supplied) and their backing washers top and bottom. The linkage has the following signs with either the new diverter valve or the (original) external cap:
1). TPL lifts much slower than usual
2). TPL can be pushed back down with my weight on the lower links from any level I set it to using position control lever.
3). the TPL falls to the lowest level within 3 seconds of turning off the motor without moving the position lever
These are all new since I began this install of a diverter valve. Previously the TPL could lift around 600kg (1300lb) and pop the front wheels in the air if overloaded.
Any ideas on solving this one?
Thanks for your thoughts

New findings:

I removed the side inspection plate that contains the dipstick and confirmed that the stand pipe was in place. I checked the orings at both ends and also confirmed that both ends "snap" into place snugly. I then cranked the motor and the stand pipe produced oil. I then cranked the motor with my thumb blocking the stand pipe and I was able to block the oil flow.

I'm guessing that this is a pump or relief valve issue. Any suggestions as to what's likely to be the issue?

 

[K5lwq]

I would suspect the diverter valve is not providing flow back to the 3pt valve if the problem occurred after install the diverter. I also suggest never to use your fingers to test pressure or look for leaks in a hydraulic system. That can cause serious damage to your fingers.

 

[FordnMassey]

I would suspect the diverter valve is not providing flow back to the 3pt valve if the problem occurred after install the diverter. I also suggest never to use your fingers to test pressure or look for leaks in a hydraulic system. That can cause serious damage to your fingers.

Hi,
The problem is present even when the new diverter valve is removed and the original external cap is replaced. So it's not the new valve causing the issue.
Thanks for the tip around hydraulic safety.

 

[K5lwq]

Then next I would have to agree on relief valve open. I would not think the pump to be an issue.

 

[Jerry/MT]

Hi,

I had this posted in Massey Vintage and no replies so trying here instead.

My MF35 has lost it's lift power on the three point linkage. I occurred after I was installing a diverter valve to the the external cap. The stand pipe was lifted clear when the external cap was removed, so I replaced the o-rings (Sparex supplied) and their backing washers top and bottom. The linkage has the following signs with either the new diverter valve or the (original) external cap:
1). TPL lifts much slower than usual
2). TPL can be pushed back down with my weight on the lower links from any level I set it to using position control lever.
3). the TPL falls to the lowest level within 3 seconds of turning off the motor without moving the position lever
These are all new since I began this install of a diverter valve. Previously the TPL could lift around 600kg (1300lb) and pop the front wheels in the air if overloaded.
Any ideas on solving this one?
Thanks for your thoughts

New findings:

I removed the side inspection plate that contains the dipstick and confirmed that the stand pipe was in place. I checked the orings at both ends and also confirmed that both ends "snap" into place snugly. I then cranked the motor and the stand pipe produced oil. I then cranked the motor with my thumb blocking the stand pipe and I was able to block the oil flow.

I'm guessing that this is a pump or relief valve issue. Any suggestions as to what's likely to be the issue?

Take the side plate off and start the engine. (UNDER NO CONDITIONS SHOULD YOU EVER PLACE YOUR HANDS IN THE HYDRAULIC COMPARTMENT WITH THE ENGINE RUNNING!)
With an implement on the three point, move the control lever to the lift position. Using a flashlight, look up at the lift cylinder and see if there is a leak. Anymore than a few drops is a leak.

Look forward at the standpipe. Is there fluid streaming down the sides? If not, the seals are good.

Look down in the oil below where the control valve is located. If there is a lot of agitated oil there, and a screeching sound, the relief valve is open.

 

[FordnMassey]

Take the side plate off and start the engine. (UNDER NO CONDITIONS SHOULD YOU EVER PLACE YOUR HANDS IN THE HYDRAULIC COMPARTMENT WITH THE ENGINE RUNNING!)
With an implement on the three point, move the control lever to the lift position. Using a flashlight, look up at the lift cylinder and see if there is a leak. Anymore than a few drops is a leak.

Look forward at the standpipe. Is there fluid streaming down the sides? If not, the seals are good.

Look down in the oil below where the control valve is located. If there is a lot of agitated oil there, and a screeching sound, the relief valve is open.

Hi Jerry/MT,

I've had that side cover off and cranked the motor, but not actually started the motor and tried to raise an implement. I am off the farm for a few days and will try these steps when I'm back. I reply with my findings.

Thanks for the advice.

 

[FordnMassey]

Then next I would have to agree on relief valve open. I would not think the pump to be an issue.

Hi,
Missed your reply somehow, sorry.
That's what I'm thinking, that the relief valve failed open.
I guess I'm pulling the pump out to check this.

 

[FordnMassey]

Hi,

Pump is removed from tractor and I found one valve assembly pushed out of the housing - see photo. There may be other issues with the pump as well, so I'm considering just replacing the pump with new from Inside via eBay.

Does anyone know how to tell it the pump in the photo is a Mark1 or Mark2? Does it matter if I swap Marks?

Anyone have experience with the pumps coming out of India?