HELP weak pump or worn lift cylinder?

[itsmesrd]

Morning Dave M7040,

Thanks for the help with this so far, the pictures are great!!!
The only thing that I'm not sure of is the drive shaft I haven't pulled the pump but am seriously thinking of it. I was gifted a few garden tools and really do need to get them moved before disabling the tractor. I haven't seen any numbers on my pump either, but all of the other pics match.
When you say "number 22 small seals" are they 22 mm or is that a part number?
The guys at the hyd shop told me that o-rings and seal shouldn't be a problem. They seem well informed and had a shop that has been in business for many years.
Do you think that a seal broken or just plain worn out, in the control valve or the lift cyl. could have the same effect? Maybe this afternoon I'll pull the pump to at least see what the shaft looks like. I can't imagine it being different given all the other similarities. While I have it apart I can at lest finally get rid of my moisture problems. I'll also pull the hyd filter again to be sure it's not clogged.
Hope I didn't come across too cheesy in the video, I have to do that sort of thing for my own benefit also. It would have taken me many hours to try and write that amount if info down. I sometimes have my son record me so I'm trying to teach him how to do some of this stuff too. When I do it myself I get him to watch them.
I'll post pics of my pump as well as the other things that I'm sure are going to come up. I need to cal those guys at the hydraulic shop...

 

[itsmesrd]

Do we know what model Yanmar tractor?

 

[Dave M7040]

Morning Dave M7040,

Thanks for the help with this so far, the pictures are great!!!
The only thing that I'm not sure of is the drive shaft I haven't pulled the pump but am seriously thinking of it. I was gifted a few garden tools and really do need to get them moved before disabling the tractor. I haven't seen any numbers on my pump either, but all of the other pics match.
When you say "number 22 small seals" are they 22 mm or is that a part number?
The guys at the hyd shop told me that o-rings and seal shouldn't be a problem. They seem well informed and had a shop that has been in business for many years.
Do you think that a seal broken or just plain worn out, in the control valve or the lift cyl. could have the same effect? Maybe this afternoon I'll pull the pump to at least see what the shaft looks like. I can't imagine it being different given all the other similarities. While I have it apart I can at lest finally get rid of my moisture problems. I'll also pull the hyd filter again to be sure it's not clogged.
Hope I didn't come across too cheesy in the video, I have to do that sort of thing for my own benefit also. It would have taken me many hours to try and write that amount if info down. I sometimes have my son record me so I'm trying to teach him how to do some of this stuff too. When I do it myself I get him to watch them.
I'll post pics of my pump as well as the other things that I'm sure are going to come up. I need to cal those guys at the hydraulic shop...

Here is the link to the pump on ebay where the bidding is over.
Yanmar Hydraulic Oil Pressure Pump for Yanmar YM155, YM155D | eBay

The pump was listed as being for a Yanmar YM155 or YM155D.

It is too son in this trouble shooting process to be pulling the pump if it is only for you to look at. Clearly it is rotating.

The seals , number 22, are unusual seals in the way they are used so your hydraulics guy may not understand this application. On the other hand they may mean matching any O ring should not be a problem.

The #22 is the part illustration number on your parts page where the lift cylinder and control valve are shown. These seals connect the lift cylinder and control valve to those hydraulic passages you screwed your gauge into. I would not think any large O ring say on the lift cylinder piston would break. The control valve internals will not have any seals just parts that fit extremely close together to prevent leaking.

I have yet to go back and watch your video again but compared to many on youtube is was excellent.

Dave M7040

 

[itsmesrd]

Thanks Dave M7040,
Did you mean #32 seems like #22 is anything but an o-ring? I should have known that I had the answer to "#"
No seriously pulling the pump would be mostly for testing but also for purging the hyd system.
That will have to wait till after 5th of Nov. Busy shop.

 

[Dave M7040]

Thanks Dave M7040,
Did you mean #32 seems like #22 is anything but an o-ring? I should have known that I had the answer to "#"
No seriously pulling the pump would be mostly for testing but also for purging the hyd system.
That will have to wait till after 5th of Nov. Busy shop.

You are absolutely correct, I am mixed up!!
These pictures have the seals I am talking about circled in red.

The hydraulic pump and lines are really self purging.

You could remove the smaller of the two lines at the rear lifter unit and run it into a bucket.

Put some rags over the top of the bucket so you don't get splashed.

If you timed and measured how much oil went into the bucket you would have a pretty good idea of the flow rate of the pump.

You would also see when clean new fluid is now going into the bucket to end your purge of the hydraulic system.

Dave M7040

 

[itsmesrd]

Dave M7040
My plan is to pull the pump, suction and pressure lines, hyd filter, and the hyd lift housing. The parts #12-#17 are to prevent the hyd lines from chaffing on other stuff, and are not in the right spot. Taking the hyds apart will also give me a chance to measure tolerances checking for ware on the control valve and its associated parts, bypass... While the pump is being tested I will be able to get new o-rings all around. Where the control lever exits the lift housing there is a small leak, just a seep really but why not fix it while it's apart? If I have too I'll rig up a suction line for my shop vac and suck any remaining wet fluid from the trans housing. I'll also have a chance to wash down all areas that were contaminated by watery oil. Home De Pot sells WD40 in a gallon can. WD40 stands for water displacement formula 40. May get a can of that to bathe the interior of the housing with.
On a side note the flow control knob has been screwed full in for who knows how long, until I got it freed up the other day. Do you think that that could have cause some of the problems that I'm having?

SRD

 

[itsmesrd]

I just found out the typical clearances for control valves is 6 to 10 microns is 0.00024 to 0.00039 inches, maybe I'll get the hyd shop to check clearances for me. Not sure my Harbor Freight digital calipers are up to the task. LOL

 

[Dave M7040]

I just found out the typical clearances for control valves is 6 to 10 microns is 0.00024 to 0.00039 inches, maybe I'll get the hyd shop to check clearances for me. Not sure my Harbor Freight digital calipers are up to the task. LOL

The big thing in control valve deterioration is scratches lengthwise along the spool. Either on the spool or the bore where the spool moves.

Trying to figure out if there is excess clearance between spool and its housing requires special metrology equipment few outside government and large companies can afford.

Fundamentals of Metrology | NIST

The flow control know is only controlling how fast an implement goes down.

Dave M7040

 

[itsmesrd]

"On a side note the flow control knob has been screwed full in for who knows how long, until I got it freed up the other day. Do you think that that could have cause some of the problems that I'm having?"
Do you think this has created problems.
SRD

 

[Dave M7040]

"On a side note the flow control knob has been screwed full in for who knows how long, until I got it freed up the other day. Do you think that that could have cause some of the problems that I'm having?"
Do you think this has created problems.
SRD

No it would not have.

The flow control knob is only controlling how fast an implement goes down.
It has nothing to do with your problems.

Dave M7040