732 (743) lift arm trouble

[732_Guy]

This is a 40 year old machine that has worked ok for the last few moths in hard commercial use. Everything was working great yesterday. Half way through the job the lift arms started acting up. I managed to finish the job. It was hard. Some times you get what you ask for. Other times you get a variety of odd and erratic behaviors- • reversed direction not asked for. This one was really weird. Half way with boom going up it will stop and slowly start going back down under power. • Sometimes heel down does not make anything happen. Other times it does. • Sometimes the loader arms seem to be fighting themselves as though one is going up and the other is going down but I am not sure. Hard to tell. But there will be engine strain with no movement at times. • Sometimes left foot toe all the way down makes boom fall real fast which is normal, and other times it goes down very very slow. • fluid level is ok • no leaks observed • problem is consistently hot or cold • no other controls are not even slightly affected My thought is the lift arm control valve is shot. If it were just a bad lift cylinder, say with internal leakage this could not explain everything we see here. Only a central component like a faulty control valve could explain all this crap.

 

[Wayne440]

Looks like you know exactly what is wrong. You are ahead of me - I cannot tell if you have a 732 or 743 machine.

 

[732_Guy]

Looks like you know exactly what is wrong. You are ahead of me - I cannot tell if you have a 732 or 743 machine.

Sorry it's a 732. (I was going to put 742, 731, and 733 in the title because of commonality, but for some reason I can't edit. Spaces are hard to insert as well.) (space) I am in for a bit of work it looks like. There is a video on YouTube of a guy doing an in-frame repair on his spool valves. (space) https://www.youtube.com/watch?v=xbLEXsSBh0Q&t=1213s (space) and here (space) https://www.youtube.com/watch?v=TzGXDd2g-fE (space) My thought is to lift the cab off (it does not tilt back on this model), pull the engine, then try to remove the bad spool from the back side.

 

[732_Guy]

Sorry it's a 732. (I was going to put 742, 731, and 733 in the title because of commonality, but for some reason I can't edit. Spaces are hard to insert as well.) (space) I am in for a bit of work it looks like. There is a video on YouTube of a guy doing an in-frame repair on his spool valves. (space) https://www.youtube.com/watch?v=xbLEXsSBh0Q&t=1213s (space) and here (space) https://www.youtube.com/watch?v=TzGXDd2g-fE (space) My thought is to lift the cab off (it does not tilt back on this model), pull the engine, then try to remove the bad spool from the back side.

If you know how to insert into posts, lemme know!

 

[Wayne440]

If you know how to insert into posts, lemme know!

FWIW, I have a 742- the last trouble I had with the lift arm function was a worn, sloppy linkage. Sometimes it would work OK, and sometimes you had to kick it pretty hard to get it to work. Other times the arms would just slowly go down with the pedal depressed all the way, then the next time you went to ease it down a little--BOOM all the way down quickly.

 

[[email protected]]

FWIW, I have a 742- the last trouble I had with the lift arm function was a worn, sloppy linkage. Sometimes it would work OK, and sometimes you had to kick it pretty hard to get it to work. Other times the arms would just slowly go down with the pedal depressed all the way, then the next time you went to ease it down a little--BOOM all the way down quickly.

it sounds to me like your aux hydraulics are engaged

 

[732_Guy]

FWIW, I have a 742- the last trouble I had with the lift arm function was a worn, sloppy linkage. Sometimes it would work OK, and sometimes you had to kick it pretty hard to get it to work. Other times the arms would just slowly go down with the pedal depressed all the way, then the next time you went to ease it down a little--BOOM all the way down quickly.

Yes that's the symptom to a tee, but I checked the rods and found some slop and nothing new or broken. What makes me think it's in the spool valve is how sometimes the lift arms actually goes the wrong direction. I don't see how loose left foot linkage could do that. I wish it were that easy.

 

[732_Guy]

Yes that's the symptom to a tee, but I checked the rods and found some slop and nothing new or broken. What makes me think it's in the spool valve is how sometimes the lift arms actually goes the wrong direction. I don't see how loose left foot linkage could do that. I wish it were that easy.

I took it to a garage here in Georgia USA to have the lift arms looked it. We will see what they say this week.