3-pt bouncing/bleeding

[sikmusicfreak8]

So this seems to be intermittent. Tried messing with the valve, but not working. Sometimes the tractor will hold the implement indefinitely, and be smooth, other times it bounces and will bleed down quickly with the tractor off.

Also, Ive got an 8620 back hoe and it bleeds down constantly. Has a brand new valve assembly in it, maybe the guy who installed it didn't tweak everything right? Hoe will bleed left and right really easily, even when running, and the stabilizers, constantly have the put them back down. And speaking of those, I have to hold the left stick down in order for the stabilizers to have any down force, is that normal?

Thanks

 

[dadster4]

Possibly relief valve sticking open or leaking? Do you hear relief opening when under load?

 

[Complete Turf Care]

Sounds like it could be what is known as hiccuping. It's caused by the 3 point cylinders leaking. You may need to have the seals changed in your 3 point cylinders. It happened to me a few months ago on my New Holland.

Here is a link to my thread about it. http://www.tractorbynet.com/forums/hydraulics/353705-3-point-hitch-hops.html

 

[sikmusicfreak8]

Difficult to service the 3 point?

 

[sikmusicfreak8]

Possibly relief valve sticking open or leaking? Do you hear relief opening when under load?

What would that sound like?

 

[Complete Turf Care]

Difficult to service the 3 point?

Can't really answer that, because I had it done at the dealership.

 

[dadster4]

When you lift too heavy of a load in your bucket or pull too hard with the backhoe the relief valve will "hiss" after straining a bit...this is normal behavior. If the relief doesn't "pop" and release pressure and just bleeds down slow, it may indicate a faulty valve. I would put a gage on the hydraulic circuit to see what the pressures do under load and when the tractor is idling to see what they are doing.

 

[sikmusicfreak8]

Well, did some grading last weekend and 3 point is bouncing very rapidly now and bleeds down very quickly.

So, I guess this needs to be addressed. Anybody know the difficulty of this repair and what parts Ill need?

Thanks in advance!

 

[DavesTractor]

It's not hard. The piston rings will be damaged/melted. Pop out the piston (comes out of the front of the rockshaft housing under the seat) and install new rings/seals.

Your tractor, like most tractors, has position control on the three-point. It strives to keep the three-point at a certain position relative to your control handle. It senses that it is dropping and corrects that drop, hence the hiccup. 99.9% of the time, it's the piston rings or seals or whatever we should call them.

Your dealer will stock the parts, it is not a rare failure on your vintage of machine. Pretty cheap and pretty fast to fix.

I'm not sure what is going on with your backhoe.

 

[sikmusicfreak8]

Dave,

Thanks for the reply. I've been buying my parts through you. Is there a seal kit? If so can you provide part numbers and I'll forward them to Dakota for order?

Thanks

 

[sikmusicfreak8]

Dave,

Thanks for the reply. I've been buying my parts through you. Is there a seal kit? If so can you provide part numbers and I'll forward them to Dakota for order?

Thanks

 

[DavesTractor]

Dave,

Thanks for the reply. I've been buying my parts through you. Is there a seal kit? If so can you provide part numbers and I'll forward them to Dakota for order?

Thanks

Well that's sweet. Dakota will know just what you need. Send her an email and she will fire back a price and availability. And thanks for the business.

 

[sikmusicfreak8]

Dave,
I went ahead and ordered the seal kit. I don't have the tractor at the house at the moment, any tips for replacing these? Am I having to drain the hydraulic fluid? Am I having to remove a lot of parts and pieces to get access to the piston?

Thanks for any help.

 

[LD1]

Just another idea I didnt see mentioned yet....

Do you have a drop speed control knob (usually under the seat) on that tractor?

If you do, raise the implement and CLOSE that valve all the way. then turn the tractor off. If it still bleeds down, its the cylinder. If that stopped the leakdown, the issue is the valve.

 

[EddieWalker]

I need to do this one of these days for my Century 2535. Is there a link anywhere to a manual or something that shows how it all goes together?

 

[DavesTractor]

It's pretty simple. You need to pull off the panel below the seat. That's the hardest part of the job. You do not need to drain the fluid. Then you will see the cover for the front of the cylinder. You can't see a cylinder, but you can see a roundish casting that needs to be removed. Make sure you have nothing on the three-point. Remove the cover for the cylinder. To get the piston out, sometimes you need to raise the three-points manually by lifting them up with your hands (don't start the tractor!) and then lowering them quickly to thrust the piston out of the cylinder. It is helpful for just a minute to have a helper to push the piston rearward as you raise the three-point, and to catch the piston as you fling it out. It is not captured by a fixed rod like an engine piston. Presto, it's in your hands. With air tools to remove the seat and seat pan, figure about an hour start to finish.

By all means do not remove the rockshaft housing. It is not necessary.

LD1 - good advice, thanks.

 

[sikmusicfreak8]

Just another idea I didnt see mentioned yet....

Do you have a drop speed control knob (usually under the seat) on that tractor?

If you do, raise the implement and CLOSE that valve all the way. then turn the tractor off. If it still bleeds down, its the cylinder. If that stopped the leakdown, the issue is the valve.

Well I already ordered the kit, so hoping that's it. If I end up pulling the hoe off I'll check that out. If it were a valve issue, what's that going to entail?

 

[DavesTractor]

Well I already ordered the kit, so hoping that's it. If I end up pulling the hoe off I'll check that out. If it were a valve issue, what's that going to entail?

On your Branson, it will almost for sure be the piston kit. I'd say 95% chance it's the piston seals. But LD1 offers good general diagnostic advice for this sort of situation.

 

[rasorbackq]

I am also having the same issue with 3 pth jumping.
and sometime bleeding down at engine off.
After reading this thread I will have to see how the seat comes off and familiarize myself with what needs to be removed. Have any pics or part breakdown?
A while back I noticed the branson part breakdown on the net was no longer working.

 

[thekidb]

Not sure how many hours you have, but I had the same issue on my 2800h with very low hours. Turns out that there was a small metal chip in the valve that caused the pulsating and quick leak down after the engine was cut off. I had to disassemble the entire valve to find it. It was flushed out with some brake cleaner and was about the size of a tiny piece of paper clip.

When I decided to tear into mine, I called Branson about the diagram. They emailed me the exploded view of the assembly.