3-Point Hitch Hydraulic lifts slowly drop over night

[barbqranch]

A related question please. I have a TC29D that I bought w/ 1000 hours. The drop knob has never worked, I can turn it some w/ no effect. It would be nice to slow down the drop. Anybody take that area apart, and is it as simple as it would seem to just take the piece out? I'm not really going to do anything with it till spring, but since it fit in this topic I thought I would throw it out.

Also, regarding replacing the piston seal, wasn't there a pretty complete thread about that recently? Fortunately, I don't have to do that.

 

[JC-jetro]

So this all sounds a bit complicated but the main idea is watch for drop during operation. If drop becomes issue I should replace piston seal, right? JC - I opened that PDF and it has many parts, this may sound stupid, but which seal/gasket are we talking about. I really don't want to take that cylinder apart and still not know what to replace.
It is painfully obvious this is my first tractor, I obtained used with 685hrs.
By the way I normally leave the 3PH down, I left it up when I changed the filter.
Although this issue is still pending I want to Thank you Gentlemen for the help.
Eastbx

p.s. when I put something heavy on the 3PH, it shouldn't drop at all with or w/o the tractor running, right?

it is part # 45 and #46 in the diagram. The piston is part#44. in your machine you actually have two seals and one is for back up. I have done a complete job when I bought my tractor first. I have a long and boring thread about it with all the skinny. I "ll post a link below. it is very informative with much good comments from the experienced folks here. Look at it and pose any question you might have. will be glad to help if I can.

JC,


http://www.tractorbynet.com/forums/new-holland-owning-operating/90819-my-f-1700-testing-my.html

 

[JC-jetro]

A related question please. I have a TC29D that I bought w/ 1000 hours. The drop knob has never worked, I can turn it some w/ no effect. It would be nice to slow down the drop. Anybody take that area apart, and is it as simple as it would seem to just take the piece out? I'm not really going to do anything with it till spring, but since it fit in this topic I thought I would throw it out.

Also, regarding replacing the piston seal, wasn't there a pretty complete thread about that recently? Fortunately, I don't have to do that.

You can take the needle valve for inspection pretty easy from the front by loosening the nut that hold it. it has a shaft seal, shaft and the valve seat at the end for inspection. are you sure the valve stroking (traveling) all the way open and close? I think it is a rising stem so when closed the knob is closest to the hold down nut and all thee way open is the furthest. In the previous post I put a link to seal replacement. You might find it useful.

JC,

 

[barbqranch]

Thanks. No I am not certain of anything. I guess when the rains stop I will just have to take a wrench to it and see what happens. One problem is the nearest dealer is about 3 hours away, so I don't want to mess up any parts and have the machine down. On the other hand, it is just a yard toy, I don't use it for a living. I will pull it apart later, and if anything interesting happens, post it in a new thread.

 

[Soundguy]

if it drops that much with no load, it might come down much quicker with a boxblade on the 3PH or other heavy implement like a rotary cutter. I'd sure check it with my heaviest implement to make sure the lift is not dropping and "hicupping" at a high rate of speed.

funny enough.. I've actually seen some leaky cyls seal better with some load on them. of course i'm sure those were vpaks and not orings.

having not been into one of those new top covers.. are they as easy to service as say.. an 8n or a hundred series ford.. IE.. undo 3pt linkage, unbolt seat.. remove remotes if any, unbolt top cover.. lift off, renew gaskets and orings and piston ring/washer.. nore if needed,then slap back on with a new gasket?

soundguy

 

[Soundguy]

hmm.. drop during operation? I'm guessing you will not see that.

untill the leak exceeds the pump flow rate, the valving will continously regenerate that circuit as long as your position control lever is not dropping.. IE.. it may bob fro a leak.. but shouldn't just drop. the bobbing is leakdown untill position control linkage causes circuit regeneration.. then cuts off oil to the piston again.. etc.. rinse.. repeat.. etc.. etc...

soundguy

So this all sounds a bit complicated but the main idea is watch for drop during operation. If drop becomes issue I should replace piston seal, right? JC - I opened that PDF and it has many parts, this may sound stupid, but which seal/gasket are we talking about. I really don't want to take that cylinder apart and still not know what to replace.
It is painfully obvious this is my first tractor, I obtained used with 685hrs.
By the way I normally leave the 3PH down, I left it up when I changed the filter.
Although this issue is still pending I want to Thank you Gentlemen for the help.
Eastbx

p.s. when I put something heavy on the 3PH, it shouldn't drop at all with or w/o the tractor running, right?

 

[ArtMech]

Eastbx, I forgot to ask IMPORTANT QUESTION (not sure if it's similar case like mine), which could change a lot - does the lift lever You're operating 3PH with, slowly drops TOGETHER with the lifting arms?

Mine L Kubota has an 'issue' - the lifting arms slowly move down with the lift lever while the engine running at idle speed, in my case because of vibration. But I don't care.

 

[ArtMech]

You might refer to attached pdf for the answer to your question.

JC,


I think the most likely culprit amongst the others is leaky piston seal that will be your cheapest and easiest fix considering the design.

I guess Your pdf drawing is quite enough to fix an issue in case of piston seal replacement. Needs to replace #41 (cylinder head gasket), #45 (ring) and #46 (O-ring) or #42 (liner) and #44 (piston) in case if required. And the bolt tightenning torque table will be needed.

 

[jinman]

ps. I don't think the OP has a major issue, and checking the piston seal is a 1 hr job tops and it is very inexpensive. I don't know if there is any deco rational sheet metal needing to be taken off to have access to cylinder head. On my 1700 it is in plane view, nothing in front it and takes a few (6) bolts to take it off.

JC, unfortunately on the TC40, the access to the lift cylinder is not like your 1700. The TC40 is a platform tractor with the seat mounted on a solid platform above the running gear. Removing the seat gives access to the area through a port in the platform, but I'm not sure the piston can be removed and serviced through that port. It may be possible and if so is a fairly easy job. The Repair Manual does not address only removing the cylinder. It tells how to remove the complete hydraulic lift cover and assy. which is a major teardown requiring removing the tires, fenders, ROPS, and fuel tank. From the illustration and my memory of the area, it is likely the piston could be serviced through the port only, but since I have not done it, I'm not going to say it can be done. It does appear to be possible.

EDIT: On further examination, the economy TC40 has a mounting plate below the seat that can be completely removed, so I suspect this job is much easier on that model than the deluxe model with the full platform.

 

[JC-jetro]

I guess Your pdf drawing is quite enough to fix an issue in case of piston seal replacement. Needs to replace #41 (cylinder head gasket), #45 (ring) and #46 (O-ring) or #42 (liner) and #44 (piston) in case if required. And the bolt tightenning torque table will be needed.

That's pretty much the case at least on most of them. As jim indicated on the more Deluxe TCs the seat is mounted on a flat base platform and not necessarily on top of the lift cover. Mine is kind of naked and every thing exposed. It might be more headache to remove what you need just to get to the cylinder and piston retrial. My suggestion to the OP is if he decides to do it it would be advantageous to take pics during disassembly and marking the bolts and associated components so reversing the process would be easier if memory fails him as we don't do this kind of work for a living. On the torque thing.. I did not have the torque spec and did not even look for it as the cylinder head is mounted to the lift cover and what seal the two parts is couple of big O-rings. I put new rubber Orings but was not necessary. The oring sit in a grove and really you do not want to compress it too hard to deform it. I went criss cross pattern and tighten it to the same tight to me enough torque.

JC,


New piston seal (one only) two main o-rings between the cylinder and head and one between cylinder head and lift cover.




Bad seal buggered up during disassembly.