3 point arms won't respond to control arm spontaniously today

[electrycmonk]

So This oddity gets its own thread.

Specific stats:
cub cadet 7260 4WD standard diesel

While cutting up the soil & removing it to put in a chicken coop with cement foundation..... the twin curled blade type tiller (don't remember the correct name for this old school tool) was cutting great. raise and lower wonderfully every time.... then all of a sudden, it wouldn't lift. I backed up the tractor thinking maybe its caught on a very big stone; then pulled the handle to full up and still no reaction at all. So, I disconnected the twin blade from the 3 point and spun around to use the bucket to move the twin blade out of the way.

Tried to cycle the engine to see if maybe the line had a pressure inducing clog on the 3 point internal stuff (my brain assuming this logical 1st thought). Still no response to the up & down of the control handle for the 3 point. Yet, the FEL still worked just fine.

Took lunch break and came in to research in forum and look at the pdf's i'd found here and online for the tractor..... didn't see anything the same. saw several stories of snow-bound issues based mostly on fluid dynamics.... Saw at least 2 on something about a internal pin and an allen head bolt(?) that a service tech didn't charge for the re-tear down to fix from the 1st go round....

So This evening about 8PM I went out to test the system...
FEL worked fine. 3 point still no response to control handle at all. So last thing to do was test to see if I could manually move the lower 3 point arms....
piece of cake! they lifted and lowered in my hands like the top link. yes they are heavy steel but, there was no detectable resistance (hydraulic or mechanical) to moving them (by hand) with the engine off and the control arm in either full up or full down position.

I thought of making a short (under 15 sec video) of this manual test but, don't think that's the best use of bandwidth out here in DSL-land. I could upload a couple pics tomorrow if that would help?

 

[jeff9366]

When did you last thoroughly grease your Three Point Hitch with moly-grease?

It could be lack of grease or it could be old, congealed grease packed in the top and bottom of lifting mechanism.

 

[Katahdin]

I've had that happen, an internal hydraulic fluid screen got loose and jammed the 3-point lift valve open. No pressure could build up to lift. A piece of debris in the hydraulic plumbing could do the same thing if your model has no screen.

Cost to fix at the dealer was about $1000 with new filters and hydraulic fluid, but it was covered under warranty for me.

 

[the old grind]

CUTs with rockshaft 3PH lift do not provide down-pressure, so it's perfectly normal for draft arms to 'float' or to easily be lifted by hand. A red herring this time, I'm sure.

"Lifts unloaded but weak overall" can sometimes be a blown seal/ring in a rock-shaft piston. (BTDT) I second that this time something has likely fouled the 3PH control valve somehow.

 

[electrycmonk]

When did you last thoroughly grease your Three Point Hitch with moly-grease?

It could be lack of grease or it could be old, congealed grease packed in the top and bottom of lifting mechanism.

i woke up this morning wondering if I had a fundimental flaw in thinking about the threads I had read in that maybe my situation is similar or the same problem - just my lack of vocabulary knowledge and system understanding.

I will take a few pictures after breakfast to show that grease is not an issue with regards to what your suggesting, jeff9366. FWIW I had sprayed penitrating lube on all the joints and pins & swivel parts the day after i brought it home -last week.

As for Katahdin & the old grind: I'm wondering what the acronym 3PH is? is it a po-tay-toe - poh-tah-tow pronouncing thing here with the "3-point lifting valve" & "3PH control valve"?

I am assuming that this is likely and internal part? Which in my learning curve thinking = fender, seat, wheel and other items will have to be removed to get into & clean this area/part and get 3-point working again?

 

[electrycmonk]

Update....i hope i can upload these pics w/out error. We're out in DSL-land with a whopping 3.5Meg download speed and .75Meg upload speed.

So to give data to pics here in case the upload is not completely successful.
picture 1: the 3 point in its current full down (dead) position
picture 2: my hand holding 3 point in nearly full up position (or full up) was difficult taking pic simultaneously & balancing it with my bad knee (smirks)
picture 3: just the upper section to show metal condition
picture 4: is an attempted close up under the seat of the control arm linkage

 

[electrycmonk]

now the pictures in that order....


"Well, Isn't That special?" - Dana Carvey as The Church Lady from SNL.

Okay got that fixed. Sorry.

 

[jeff9366]

As for Katahdin & the old grind: I'm wondering what the acronym 3PH is? is it a po-tay-toe - poh-tah-tow pronouncing thing here with the "3-point lifting valve" & "3PH control valve"?

3-PT = (Ferguson) Three Point Hitch

Diagram and component nomenclature: TractorData.com - Three-Point Hitch

 

[powerscol]

Have you checked your fluid level?
If you have any other remotes, check their position. If open 3pt will not function.
Do you have a 3pt control valve with handle that you adjust the rate of drop with (also locks 3pt at a specific height). If this is closed 3pt will not function.

Good luck

 

[/pine]

Unless I missed it the OP did not say if they had checked the nut on the 3ph lever to make sure it is actually moving the internal rod and it's not just slipping...?