Broken Hydraulic Filter Housing

[wdlanning]

I have been working on the 3-point controller for the B8200HST. Re-installed the controller and started the engine. When I raised the lever full up, the filter was pressurized and broke the male fitting that goes into the filter. This filter is down stream of the controller and before the transmission. It is on the discharge side of the pump.
The filter was not damaged and the discharge line to the transmission was not obstructed. Fluid level in the trans was low. Will need a new part.

Some previous filter failures were attributed to cold weather, but I am skeptical.

 

[200mph]

Your lucky this part broke and not something else more expensive or difficult to fix.

I’d be checking pressures at low rpms (first) before going any further.

Good luck with the diagnosis and report back when you find the root cause.

 

[100 td]

I don't have a WSM or hydraulic circuit but I "assume" the filter is in the charge circuit. If it is, cut the filter open to inspect for contamination or plugging, check the charge relief valve for cleanliness and operation/setting if you have gauges.

 

[wdlanning]

I have replaced the HST filter bracket and filter. I have not started the tractor because I am waiting for pressure gauges and fittings to check the HST pressure. I doubled checked the hydraulic plumbing and it is correct.

This over-pressurization is a repeat event for the tractor (not for me). The HST filter bracket has been replaced previously and the 3-pt controller has been welded probably due to cracks. Also, the tank port from the FEL has been plumbed directly to the differential case. Guessing that was done to minimize flow the the 3-pt controller.

Would appreciate someone explaining how the HST can become pressurized given there is a vent on the 3-pt cylinder structure, dip stick, and there are two plastic caps on the trans.

A knee jerk conclusion would be that the filter was too small to pass the flow from the pump. This time the weak point was the filter bracket. The filter was a Kubota filter and my replacement has the same number.

After checking the HST pressure, my next step will be to bypass the filter and see the results. I expect the trans pressure to be within limits and the 3-pt hitch will begin to work (it goes full up and will not go down). More to come

 

[100 td]

This over-pressurization is a repeat event for the tractor (not for me).

Did you cut the filter open?
Was the filter bulged in any way? From the second pic it appears that it may have been?
3pt goes full up, check feed back linkages, also draft control lever position and linkages. Also make sure the lowering speed adjustment knob is actually opening the valve.
Do you have a WSM? If you do, post up the hydraulic circuit for comment.
Do you know if the tractor has been split before?
I wouldn't bypass the filter to the HST.

I have been working on the 3-point controller for the B8200HST. Re-installed the controller and started the engine. When I raised the lever full up, the filter was pressurized and broke the male fitting that goes into the filter.

What did you do the the 3pt controller exactly?
It appears the 3pt is going to full stroke and into relief or not relieving and possibly pressurizing the charge circuit, need the hydraulic diagram if you have it.
YMMV.

 

[wdlanning]

Re: Broken Hydraulic Filter Housing on B8200HST

Thanks 100TD for your reply.
The arms will fall down after the engine is off for some time. When the engine starts the arms come full up. The lever on the control valve has no effect. Lots of force will not move the arms down.

FEL works fine...maybe a little slow. I noticed that the return from the FEL valve is plumbed to the port on the transmission under the seat (bypasses the distribution valve). I will correct this at some future time in the event the FEL is removed.

I have tried disconnecting the feedback arm and moving it along with the lever, but no change. I did manipulate that handle in every direction...no effect on 3pt. When the lever is moved to full up position, it puts a load on the tractor so I immediately moved it to the down position. No sounds from the control valve. This valve has been worked on previously, but not by me, so I don't know what was done.

I had replaced all O-rings and springs in the 3-pt controller. That's when I went to full up on the controller and the filter bracket broke. The filter was not deformed. I have verified that the hoses to/from the FEL controller and block valve are correct and there are no obstructions.

I was going to bypass the filter only to determine if it makes a difference in the loop pressure. I will check the HST first to confirm it's not over-pressurized.

 

[North Idaho Wolfman]

I most certain that you have an issue with the three point controller and it's not operating properly and not relieving pressure when it's supposed to.

Considering you said it was cracked before I wouldn't rely on it working properly.

I would go through all three pressure relief valves and make sure each one is in working condition.

 

[wdlanning]

Finally got back to the B8200 and the broken hydraulic bracket and blowing the seal from the hydraulic filter.
I pulled the relief valve in the hydraulic block and found that there were no shims in it. This reduced the pressure to permit continuous flow to the 3pt controller from the pump. Whenever the RPMs were increased the filter seal would be blown out. The excess flow to the filter could not be relieved to the transmission before the filter seal failed.

Parts book shows three shims...anyone know the thickness of the individual shims?