Yanmar 240 Loader Hydraulic issue

[Soundguy]

Ok, no problem, you have no understanding of Hyds..

In an open circuit Hyds system, the pump continually pumps, and if a valve is not used to direct oil at a cyl, its dumped thru the valve back to the tank. Only pressure there will be interior hose surface ate resistance to flow based on hose Id and gpm of pump. Much lil a garden hose.. On, with nothing restricting the open end it just pours out.. Put your thumb on the end, restrict it, pressure goes up, flow goes down, and it sprays.

If your system is open circuit there is no appreciable pressure till a valve sends fluid power somewhere other than sump. You can get low double digit pressure from min resistance, and if it uses a backpredsure valve.. Lil 40 psi, etc.. Not much..

There are other Hyds systems, closed circuit, etc.

 

[Soundguy]

Well, look at it this way... There are those of us that can, and there are those of that can't.. We're to try to help those that can't

Sure.. But should it take high double digits of posts saying to observe return flow, or to see if the loader comes down with hose off?

Really..

 

[kenmac]

Sure.. But should it take high double digits of posts saying to observe return flow, or to see if the loader comes down with hose off?

Really..

I concur

 

[clemsonfor]

yes you are correct a hose pressured up to 2500psi will spurt out unde quite the pressure!

 

[jb92563]

Last weekend I opened up the hydraulic lines to the Loader raise cylinders at the valve, then at the cylinder and checked that hydraulic fluid was making it to all those points in both the raise and lower circuits, which it was.

Oddly the loader bucket would not lower with both lines open so there must be something going on inside the cylinders themselves. Somehow they are jammed up internally?

I did remove one lift cylinder and with the hydraulics hooked up I could not get it to move in either direction.

I guess I'll have to take the thing apart. I'll also try the other cylinder while disconnected from the frame to see if the cylinder will move at all as its does not seem likely that they would both jam up at the same time. By doing this I am hoping to confirm that the Hydraulic pump is still functional by getting one cylinder to move.

Still seems odd though that even though the lift cylinders are not working, the bucket curl should at least work. Thats why I suspect that there might be something wrong with the Hydraulic pump.

I also made sure that hydraulic fluid would flow at all the couplings on the lift/lower circuits, which it does. I suppose I should try the bucket curl circuits as well.

I can't imagine how a cylinder could bind while nearly fully retracted but opening it up may reveal some major failure.

Now that I think about it, I did notice on a few occasions that the bucket lowering was not quite smooth, a little jerky and perhaps that was a sign that something was starting to bind inside a cylinder.

I get the feeling that I will be ordering 2 new cylinders soon.

 

[Soundguy]

as has been said.. make sur eit is not a mechanical hangup in the laoder frame too.

with the cyls disconected from lines, try moving them.

put a pressure gauge in one of the valve ports and pressurize that circuit.. see what the pump can make and then relieve at.

use a 3000 psi gauge.. most ag pressures are in the 2500 psi range..

 

[Soundguy]

as has been said.. make sur eit is not a mechanical hangup in the laoder frame too.

with the cyls disconected from lines, try moving them.

put a pressure gauge in one of the valve ports and pressurize that circuit.. see what the pump can make and then relieve at.

use a 3000 psi gauge.. most ag pressures are in the 2500 psi range..

 

[clemsonfor]

i was thinking too, time for a pressure gauge. I would block up the loader and take the cyliners off and see if they will retract with they out of the loader mounts and then start digging from there again. a pressure gauge if you can find/borrow one will tell you if the pump is working.

 

[jb92563]

Mystery solved!

I had some time to work on the tractor and figured after trying all the other suggestions, that the only thing I had not taken apart was the auxiliary Hydraulic pump for the loader.

2 Bolts off the pump and it slid right out, which is not what I was expecting as I figured there was something holding the coupling onto the pump shaft.

Nope, the set screw and shaft key were both gone.

No key, no set screw means the shaft of the hydraulic pump was not turning = No front end loader hydraulics.

Since I started this thread a Tractor Supply store opened across from the Home Depot so shaft keys were readily available, not in the correct size so I had to do some creative key reshaping with the dremel.

At first test the bucket curl is working again but I think I need a few more minutes to get the bucket lift working by getting all the bubbles out of the lines.
I read that it bleeds itself so the bubbles work their way into the reservoir after operating the Hydraulics for a few minutes.
My battery died so I'm waiting to for the charger and thought I'd update this subject. I hate unsolved mysteries.

Thanks for all the help offered. I learned a lot about hydraulics in the process and once again that its always the $1 part that typically breaks and should always be suspected first.

Ray

 

[Soundguy]

Thanks for posting back.

Yup, its always a pita when a 1$ fuse stops a $$$$$ machine.

 

[winston1]

Looks like 284 International had you diagnosed in post #4. Glad your up a going.

 

[Soundguy]

I'm still wondering why it did not drop via the spool control.. It should.. Even with no pump.....

 

[clemsonfor]

I am with you on this SG,??? Even with out the pump on or connected the valve should still allow the fluid out of that cylinder and the bucket to drop?

 

[Soundguy]

Yup.

I all the time will leave a bucket up and the machine off to do something, then just yank on the spool to drop it when done.

Just the other day I picked up a bale of hay on the spear in my loader bucket, lifted it, then killed the tractor as i forgot to empty the truck bed first.

emptied bed, and then pulled the bucket curl handle to tip the bale in and let it slide off. never did have to start the tractor. Just drove the truck away out from under the loader bucket. Then when i got out of the truck to open the gat I just pulled the other spool to drop the bucket so it would not be staying up and perhaps trap a horse or dog.. etc if it fell.

There is some BIG part of this story we are not hearing. the simple lack of pump / pressure just means no more 'UP'. Down is free, up costs ya.

 

[clemsonfor]

I see there looks like a new designation of "old timer" that you have SG!! I was thinking super member was it. I have not posted on here near as much in the last 4 years or so so my posts have kind of stagnated. I want to get back on here and post more just i am busier than ever and a few more forums also i share my time with.

Glad to see some of the old guys that still post just as hard. I still miss folks like dargo loved his sig lines.

 

[clemsonfor]

I see there looks like a new designation of "old timer" that you have SG!! I was thinking super member was it. I have not posted on here near as much in the last 4 years or so so my posts have kind of stagnated. I want to get back on here and post more just i am busier than ever and a few more forums also i share my time with.

Glad to see some of the old guys that still post just as hard. I still miss folks like dargo loved his sig lines.

 

[Soundguy]

I see there looks like a new designation of "old timer" that you have SG!! I was thinking super member was it. I have not posted on here near as much in the last 4 years or so so my posts have kind of stagnated. I want to get back on here and post more just i am busier than ever and a few more forums also i share my time with.

Glad to see some of the old guys that still post just as hard. I still miss folks like dargo loved his sig lines.

I think they upgraded the designation when they got a look at a picture of me. Beard is more grey than anything

 

[Soundguy]

I still remember some darn funny sig lines.

i remember one where a guy used tons of comma's and said something like:

,,,,,,,,, gas kills the &^%$ out of bees,,,,,,,,,,

 

[clemsonfor]

i remember some from Dargo..they would be like

-blue prying thingies from Harbor freight
-$0.99 yellow handled hammer from Harborfreight
-B&S 5hp push mower on three wheels.

Maybe not all that at once but different times.

He kind of inspired my sig line where i listed all kinds of stuff kind of poking fun at the others lists of all their stuff. i listed all kinds of random stuff in mine. They now have reduced the amout you can have in your siq line and when i go into edit it, it tells me i have to ruduce to XX numbers of characters and it would like delete half my stuff. I wanted to change it around and update mileage and add stuff. I really need to put an update the saturn blew a head gasket at 251,000 miles last week and will be sold as a project vehicle to someone as i have too much stuff to worry about fixing it anyway.

 

[normde2001]

I think they upgraded the designation when they got a look at a picture of me. Beard is more grey than anything

As I recall, March 2002 was when TBN first added a Yanmar forum, thanks to Roger-Scottie and most folks from the Yahoo, Jay Brown, forum migrated over,