massey 220 low hydraulic power to hoe

[sam un ont]

I am not familar with hydraulics so please bear with me if my questions are really dumb. My old friend down the road has a massey 220 hoe that had been working fine but had been taken off the tractor [massey 3165] for a few years and then reinstalled. .He now finds that there is almost no power to anything on the hoe but the front bucket works fine. He at first thought that the valve body on the tractor was in fault so he replaced it with no luck. He also tells me that if he restricts the return line from the hoe while activating the hoe he can get things working. i am suspecting a relief valve or something is causing trouble but that is only a guess. any help in pointing me in the right diagnostic direction is appreciated and sorely needed sam

 

[J_J]

I suspect there is a bad QD in the return line.

If that is an open center system, do you have the OUT port going to tank, and the PB port return to the tractor 3PT?

What might happen, if the PB out from the BH is restricted, the BH relief valve will operate and the hoe will operate somewhat with whatever GPM's the relief valve will pass on to the tank.

Make sure the flow from the PB is open and completing the series circuit, probably to the 3pt.

Does the 3pt work with the BH installed?

What is your hyd flow path from the pump to the tank?

If the relief is activating, install a hyd gage on the IN port, and PB port and check pressure .

 

[sam un ont]

what you are saying does make sense. he tells me that he has replaced the q.d,s with no change please forgive my lack of knowledge but does PB stand for power beyond does this system have a regenerative valve like case and is there any easy way to prove a restricted return line other than replacing. i believe we are on the right track as he now tells me that when it is running he can hear a hissing noise from the BH valve body sam

 

[sam un ont]

i was only assuming that the main relief valve was on the bucket valve body . if the problem is a restricted return line which in turn would trigger a relief valve would it not reset itself temporarily when one of the cylinders is activated sam

 

[sam un ont]

i was not ignoring your other questions it is just that the set up is 20 miles away and it will be a couple days before i get there and in the meantime i was getting as much info as i could sam

 

[J_J]

The BH should have three hoses, PB in hose, tank hose, and PB out hose to next valve.

Yes, PB is power beyond.

Is the hyd system plumbed like this? Pump to FEL, PB out to the back QD fittings, from BH, to 3pt, and another hose to tank.

If the return QD is bad, the 3pt should not work if it is in series after the the BH.

You can either replace the bad part of the QD set, or use a nipple to connect the hoses together.

You can make a hyd test gage set like this and either install it permanently, or put a QD on the hose end for testing. Just plug it into a QD for pressure test.

If your BH is using two hoses with QD at the back, if not using the BH, you would jumper the two hoses with a short hose. If the 3pt now works, that means that no flow was flowing from the BH. The return hose will have flow, because the relief is allowing fluid to flow. If you hear a constant hiss or screech, that is not good. That sound is a warning that the valve is relieving fluid.

 

[sam un ont]

the tractor in question is the industrial model so has neither 3pt nor pto. it has 2 lines from the hoe one of which connects to the pb valve and the other to resoirvoir sam

 

[J_J]

Sam,

Is the PB hose from FEL connected to the IN port of the BH valve.

Is the tank hose from the BH going to the tank/reservoir?

If the loader works fine, that means that you have good pressure, and you should be feeding the BH with the fluid from the FEL valve via the PB out port.

If the BH valve is the last valve in the hyd system, the return hose must go to tank with no restrictions.

Relief valves only work until the pressure is relieved. Sometimes they get jammed up and the fluid flows out to the tank. If you install a gage at the BH IN port, that will tell you if you have pressure to operate the BH.

If the pressure gage is installed , if no valve is being operated, there will be no or a little pressure on the gage. If you operate the BH lever, you should see the pressure.

 

[sam un ont]

that makes sense. went down yesterday to check some things out and while moving some dirt for him the splines on the front pump went out so that,s the first job. is there any easy way to get the shaft drive out from the front pulley . is it splined there also or threaded? yes the feed line from the fel is hooked to the pbv . P.S. thank you for your halp sam

 

[sam un ont]

went over today to pull the pump and tackle removing the shaft and found the the front coupler had broken in half which explained why the shaft was not turning. fortunately this created a lot of slack in the threads and i was able to unscrew it with a pair of pliers. it was evident from the break on the coupler that it was an old break that finally gave up. the splines on the shaft are good but have sent it to a machine shop to clean up the threads I will keep you posted sam