354 (2005 vintage) three point hitch not working

[stevem5215]

Have you replaced the fine screen in there ? They get damaged easily and that's how the valve could have gotten junked up.

 

[DonRina]

Not yet, but did remove the old one and cleaned it out. No damage to it but I’ll replace it in the near future.

Be nice to have a listing of all the o rings on this tractor. They are somewhat strange sizes.

 

[piper184]

The o-rings are going to all be metric sizes. Some will be close to imperial, but usually just not quite right.
Unfortunately the assortments of metric sizes I have found don't seem to have many in common with the tractor.
The will be listed by OD, ID and diameter (thickness) of the ring. Online dealers like Circle G and Affordable seem to be the best place to get the sizes you need.
Do you have a parts book for your tractor?

 

[DonRina]

The o-rings are going to all be metric sizes. Some will be close to imperial, but usually just not quite right.
Unfortunately the assortments of metric sizes I have found don't seem to have many in common with the tractor.
The will be listed by OD, ID and diameter (thickness) of the ring. Online dealers like Circle G and Affordable seem to be the best place to get the sizes you need.
Do you have a parts book for your tractor?

No, no parts book. I did get a selection of o rings as well as head gasket with the tractor though.

 

[DonRina]

As an update to this thread. The arms did work for about 10 months and then started behaving similar to the initial way. I’ ve taken it apart and found the inner valving somewhat tight. I think crap got in in spite of the flushing. This valving is very susceptible to being affected by miniscue sized pieces of crud. I have it all apart so will post pics tomorrow.

Bit of a pita.

 

[DonRina]

If anyone has a decent diagram for the two lever type of distributor could you please post it. All the ones I’ve seen are for the single lever externally mounted type. Mine is inside the three point box. Thanks!

 

[DonRina]

Here are the photos of the distribution block. What ends up jamming is the small valving assembly (photo with wrench at the side.) Clearances are quite tight so it doesn’t take much to jam it.

Looking at my filter the spaces between the mesh are too large to trap the size of pieces which can cause a jam. Maybe there is a better filter out there?

 

[piper184]

Since I have no direct knowledge of this particular setup, I can only offer some speculation and observation.

First, are the spools and bores absolutely polished looking with no score or wear marks? These close tolerance fits can't put up with much roughness, even if the sealing is done with o-rings.

Also, if there is enough wear in either the spool or the bore, the spool can cock off to one side and cause it to jam. The fit between the spool and bore is the only guiding surface to keep things "square".

When you took it apart, were you finding debris in the valves?

Perhaps o-rings from another source or material would be a good thing to try. If you take the old o-rings to a hydraulic shop they should be able to give you options for different materials. The parts department in a Caterpillar dealership is is used to doing this. I don't know about other equipment manufacturers but I would bet most of them could help with that.

From the picture of the suction screen, is there a bunch of debris stuck in the screen or am I just seeing drops of fluid that are held in the mesh?

That screen definitely looks more porous than the one in my 284 tractor. Mine is a very fine mesh bronze or copper screen. Very delicate and I tore it when I removed it the first time. Not having a spare, I found a motorcycle oil filter that I was able to adapt to the pickup tube and ran with that for several years. But that was not a good solution. It was a far superior filter, but it was too restrictive and caused flow and cavitation problems in cold weather, no matter how thin of fluid I used. I eventually went back to the mesh pickup screen.

The best solution is to have a fairly course pickup screen feeding the pump, then a high pressure filter in the output line of the pump before it gets to any of the rest of the system. Some of the Jinma tractors came from the factory with this setup, at least the 200 series did, as the parts books show both systems. It seems that in the early 2000's there were a lot of different configurations of these tractors.

It shouldn't be too hard to do a retrofit and add a filter on the pressure side of the pump. Probably wouldn't even cost that much, but somehow I always seem to have something more important to do...

 

[DonRina]

Thanks for the reply. The spools and bores were tight on the parts next to the wrench on the bench. The other ones were all ok. While I didn’t find any specific crud on the tight spools there was obviously something in there as once separated and cleaned up they slid in and moved as they should. Really doesn’t take much to jam these. The factory screen is supposed to be 100# or 150 microns…seems to course to me I’m not a hydraulics person. My screen does have some crud, mainly on the bottom part. I’ve since taken it out and am trying to find a replacement locally but will probably end up ordering one. Maybe a filter on the return side would be good as well but that might be a later project. Timing is part of the problem as the tractor is sitting in the attached garage…wife not happy. I wanted to do some other work, brake job, clean up the charging system contacts, replace a tie rod etc but I have the parts on hand for this. Be great if I could source a local filter looks like 43mm x 125mm long filter.

 

[DonRina]

New filter vs old from another post just in case it was missed by someone with the same problem.