Yanmar 240 Loader Hydraulic issue

[Soundguy]

Yup, Leonard was decent folk. I had some cobbled stuff for an air cleaner and he helped me find parts.

 

[jb92563]

I have to agree,, If the pump is all that was wrong.. What kept the bucket from falling to the ground ??
Pump controls up, curl, dump but ,it should free fall if pump doesn't pump fluid

My bucket will fall with the engine off

It IS very peculiar that the levers could not release the pressure to lower the bucket, but now that the aux hydraulic pump is turning again the bucket operates normally, plus I am able to lower it to the ground with the engine running or not.

There is a bit of sticking on the way down some times, even under power so perhaps the cylinders need to be rebuilt or replaced as well.

It seems to be defying logic and gravity.

However I have learned since then, that time slows when there is less gravity so maybe there is a disturbance in the local gravity field causing this phenomenon
I should try it again after moving the tractor away from its usual parking spot :confused2:

 

[Soundguy]

are your lift cyls SA or DA?

 

[jb92563]

Sorry for the long absence, many things going on but at least I resolved my Hydraulic issue and I wanted to circle back and close the loop.

Are you ready for this?

The key on the aux hydraulic pump shaft was missing, hence the PTO turned but not the shaft of the Hydraulic pump and so its no surprise that I had no hydraulic pressure to operate.


There is a screw that goes through the keyway to lock the key and shaft in place and I guess it got loose and the key worked its way out as it was not sheared but simply missing.

I don't like that design but in the end I simply replaced the key and used a better screw and its all operational again.

The problem was hard to diagnose because the Aux pump shaft was visibly turning but when I went around the to controls as soon as I tried to work the loader it would get a tiny bit of movment and then stop.
What was probably happening was the shaft would turn but as soon as some resistance was met in the pump I presume the Aux pump shaft would stop spinning and no further pressure developed.

I guess I learned a few things about the tractor along the way.

One of these days I'll have to address the leaking hydralic cylinders next. I go through 2, 5 gallon pails of Hydraulic fluid each year.

 

[Neat 1500]

One of these days I'll have to address the leaking hydralic cylinders next. I go through 2, 5 gallon pails of Hydraulic fluid each year.

My that's some leak. I think if you fix it the savings in hydraulic oil will be recouped in a year or 2....

 

[California]

Rebuilding hydraulic cylinders is idiot simple. Take them apart and take the existing seals to a specialist hydraulic shop for replacements. Reassemble.

The only thing that might be difficult is the amount of force it takes to unscrew the end caps. My first repair was done by a professional shop, I saw he just used a giant pipe wrench to take off the end cap. Next time one leaked I bought a 36" pipe wrench and needed a cheater pipe on that. Tip - leave one end of the cylinder attached to the tractor so you have something to wrench against.

Even if you need to buy a specialty wrench for the end caps, you will be way ahead doing the work yourself. Study diagrams and instructions for the type of cylinders you have, then just do it. You can always take the cylinder in to a pro shop if you get to a point where you can't get any farther.

My first cylinder cost $165 for the pros to do it, next ones about $10 each to just buy the seals from the same shop.

 

[jb92563]

Rebuilding hydraulic cylinders is idiot simple. Take them apart and take the existing seals to a specialist hydraulic shop for replacements. Reassemble.

The only thing that might be difficult is the amount of force it takes to unscrew the end caps. My first repair was done by a professional shop, I saw he just used a giant pipe wrench to take off the end cap. Next time one leaked I bought a 36" pipe wrench and needed a cheater pipe on that. Tip - leave one end of the cylinder attached to the tractor so you have something to wrench against.

Even if you need to buy a specialty wrench for the end caps, you will be way ahead doing the work yourself. Study diagrams and instructions for the type of cylinders you have, then just do it. You can always take the cylinder in to a pro shop if you get to a point where you can't get any farther.

My first cylinder cost $165 for the pros to do it, next ones about $10 each to just buy the seals from the same shop.

Well thats good to know that its pretty simple job.

I guess I'll start with the 2 bucket curl cylinders to get my feet wet.

The built-in 3 point hydraulic seals need to be renewed as well since the 3pt leaks down fast and doesn't operate that well, even with the lock applied.

 

[Soundguy]

the question still remains of why the spool valves would not drop the loader when the machine was off. no pump needed for that to happen..??

 

[jb92563]

the question still remains of why the spool valves would not drop the loader when the machine was off. no pump needed for that to happen..??

True, that still does not make sense to me either as with the tractor off I believe I have been able to lower the FEL in the past.
I'll have to try that though to confirm, as it might be some kind of safety feature of the Hydraulic circuit to prevent movement with the tractor off and hydraulic pump off.

 

[clemsonfor]

True, that still does not make sense to me either as with the tractor off I believe I have been able to lower the FEL in the past.
I'll have to try that though to confirm, as it might be some kind of safety feature of the Hydraulic circuit to prevent movement with the tractor off and hydraulic pump off.

not on something this old and simple!!