IHI 15 NX OR Similar

[Doug Blair]

hi. Small prolbem i dont understand. On nx15 the pedal on the floor to swing the boom only works going one way. Sitting on the machine i can get the boom to swing to my left but it will not return to center or swing to the right. Traced the control cable down to the valve block and can see it moving when swinging right. Also see 4 small bolts on the side of that valve holding a plate. Have not removed them because of inexperience. Any help would be greatly appreciated.

 

[Kobe Steel]

If the control cable appears to be both pushing and pulling the boom spool ok then try checking the anti-cavitation/suction valve installed above the boom swing spool. It could be bypassing oil to tank during operation of the boom swing spool to the right.
See diagrams attached.

Best regards

 

[Doug Blair]

Thank you so much for the reply. Sorry for the later answer as i was doing a bit of work. Had to keep cracking the swing cylinder hose every 4 hours as it kept creeping to the left. took the side c9ver off and can see the valve. Looks like the one on the left of the diagram you sent. The bottom caps are held on with 2 allan screws, but the top one has a single allan screw in the center and a nut screwed on. I am guessing that is the part you said to check. If so what do i do to check it or check for..
I am by no means a mechanic but was a welder before i retired. I really appreciate your help.

 

[Kobe Steel]

No problem. Remove that valve by using a spanner or socket on the external hex. Once the valve has been removed you will see on the end of the valve is chamfered poppet that is lightly spring loaded. You should be able to push the poppet against its spring and the poppet should have a fine ring like mark which is where it has been seating in the valve bank housing. If the poppet or spring is damaged or not seating in the valve bank housing then the oil flow going to the boom swing cylinder will bypass to tank.
If unsure try taking photos of the valve and posting.

Best regards

 

[Doug Blair]

Ok will do next week. I thought maybe something might be jammed in there. I just replaced the many Nachi pump so you never know if a bit of something was in the line

 

[Doug Blair]

Hi Kobe. Took it apart and this is what i found. Could not see any marks on the pointy part.. Could not see anything amiss inside. Cleaned both inside and out and put it together again and still only have swing to the left. Cracked the hyd line yo the cylinder and i have flow but have not tried that with motor running

 

[Doug Blair]

Disconnected the hose with motor off. No flow. Started motor and engaged pump arm rest and had flow. Went from idle to running RPM and flow did not change.. Swung to left but would not come back. Just a guess but could it be a problem in the cylinder. Thanks for any and all help

 

[Kobe Steel]

Disconnected the hose with motor off. No flow. Started motor and engaged pump arm rest and had flow. Went from idle to running RPM and flow did not change.. Swung to left but would not come back. Just a guess but could it be a problem in the cylinder. Thanks for any and all help

Yes you possibly could have an issue with the seals in the cylinder but I would think with the way it is responding would be that the piston in the cylinder has come off the end of the rod. If possible try swinging the boom all the way to the left then remove the hose from the rod end of the cylinder. plug the hose and operate the cylinder to the left again. if the cylinder is bypassing internally then oil will flow out of the cylinder port fitting. repeat this process again but instead for the opposite end of the cylinder. if the piston has come off then it will most likely bypass in one or both of these tests, just be careful during your tests as you are being exposed to the fluid at high flow and pressure with the open ports or hoses.

Best regards

 

[Doug Blair]

Ok. I will get some plugs on monday and try that. Also thought after i sent that message that even with the cable moving the valve both ways i will try to see if i can hook it somehow and make sure it is moving enough. Cant remember if going right with the boom is pushing or pulling the plunger in the valve. Not sure if i mentioned this before but for a while before it stopped working sometimes i had to plant the bucket and then swing the house to get it to move. Thanks again for the help

 

[Doug Blair]

Kobe. Progress I think. Got down and really cleaned the area where the cable and valve body come together. In the photos you will see a u shaped part and in the center the round stem coming out of the valve. Swinging left i can see the cable pulling that valve stem out. When i go back to neutral it goes back in, but when i try to swing right nothing moves. So going left it is still in the neutral zone. Up at the pedal i can see the cable moving in and out. Does this help you helping me. The 1st photo the u shape on the right side. 2nd on the top of the photo. I need a smaller telephone

 

[Doug Blair]

Should say..... So going RIGHT it is still in the neutral zone

 

[HarleyHappy]

Sounds like your swing cable needs to be replaced or if possible adjusted.
That stem, bolted to that U piece, should go in and out and neutral is in the middle.
I would disconnect the cable from the swing pedal and try moving it by hand.

 

[Doug Blair]

Ok thanks. Will do. Hoping it is the cable not a valve problem. Though not sure how you would ever get to the valve end of the cable. So much stuff in such a small area

 

[Kobe Steel]

In the photos you will see a u shaped part and in the center the round stem coming out of the valve

The U shape or clevis fork is attached to the spool with a clevis pin which is the round stem I believe you are referring to. This Fork should move out of neutral in both directions so if the fork and spool is only shifting one way and not the other then there is an issue with the cable system going back to the foot pedal for the swing boom or the spool is jammed. looks like your getting close to the cause of the issue.

 

[Doug Blair]

Another guy answered and said i should try unhooking the cable at the pedal end and try moving it that way. When i was looking at the cable yesterday i noticed some of the outer sheath is coming off. So today will try that. Not sure how you would ever get in there to get that clevis pin out..

 

[Doug Blair]

Ok Kobe and Harley . Took the pedal right off the machine and put a screw driver through the eyelet and pulled up. Boom swung to the left no problem. Pushed down on the screw driver until i hit bottom and nothing happened, it did not swing back to the right. it does not move real free but can be moved and i did hit bottom trying to get it go back. What should i do next? I think removes the idea that the cable needs adjustment if i hit a hard stop at both ends?

 

[HarleyHappy]

Well, if you can’t get movement to the spool for right swing, then it’s either the cable is bound up or there is a problem with the spool moving at the valve body.
As tight as it may be, you have to get to that clevis at the spool and see if it will push in. A long rod maybe, remove some stuff.
At this point, it’s probably 50/50 it’s a sprung cable or a valve issue.
Where you say moving the house helped it move, it may be a valve issue or is it possible the cable got pinched and bound up.
Don’t forget, when you took the cable free, the housing of the cable is not locked in so the inside cable movement will be tough.

 

[Doug Blair]

Ok Harley i will get a friend over to work the cable as i use a mirror to see if it will push in.. I am getting the feeling it is not the cable because the cable is mounted to a bracket just under the pedal. I did not remove it from that bracket but just the pedal. With a screw driver in the eyelet i can get it to go both ways until it hits a stop somewhere, might be the pin going in and out of the valve is that stop . IF it is the valve does that mean it has to come out or can a person get at the problem though the little plate with the 4 bolts on the side of the valve. And if it is inside the valve what would happen to let it work one way and not the other, i have never seen inside of a valve. Thanks so much for your help

 

[HarleyHappy]

Okay, so the way it stops hard could be in the spool but could also be something simple, like the clevis pin has worked its way out and is binding.
The spool may have a 2 or 4 bolt cap, that will have an o-ring seal and you can pull the spool out and check for damage.
If there has been no major events and this just started suddenly, I still think it’s probably a cable or linkage issue.
Sometimes this stuff is so tight, you just wanna walk away but somebody’s got to do it.
Those spools have a spring to center and some seals between each chamber, neutral, left, right.
You can look up utube videos to get an idea.
Any chance you have any manual?
Cables will get kinked and frozen inside.
I just had to replace a couple the other day, I got them from Bunker Hill Cables.

 

[Doug Blair]

Ok i will recheck the clevis pin but am sure it is in place. When you replaced those cables the other day after installation were they hard to move. Mine works but is a hard pull or push. I do not have any manuals for my machine. I still need to get a friend to work the cable as i watch the movement at the valve end. Thanks for the name Bunker hill. The 4 bolts i mentioned earlier are on a plate bolted to the side of the valve body. For example a plate on the side of a transmission to mount a PTO