742 Melroe Control Valve repair question

[rkenshin1]

Hi All!

I've found this forum to be a wealth of information for the first skidstee I've ever had, and only for a few weeks now.... Hopefully I can actually help someone else out in the future.

My question - I have to check, clean and possibly replace the tilt load check poppet valve... What I don't know is, how much oil will drain out once it's open? Should I be emptying the hydraulic oil tank first? If it's significant, is there a way to limit it, like lifting the arms and supporting them?

Finally, does the answer to those questions also apply to removing a spool, or relief valve if that became necessary later?

If anyone was wondering why, it looked like the best thing to check firet for bucket tilt drop under load, where it also drops when you first begin to try to raise it. It also has a fun problem with the arms where they sometimes come crashing down full speed, but I'm still replacing bushings on the linkage to tighten that up before digging into anything else.

 

[fortworth-cowboy]

Hi All!

I've found this forum to be a wealth of information for the first skidstee I've ever had, and only for a few weeks now.... Hopefully I can actually help someone else out in the future.

My question - I have to check, clean and possibly replace the tilt load check poppet valve... What I don't know is, how much oil will drain out once it's open? Should I be emptying the hydraulic oil tank first? If it's significant, is there a way to limit it, like lifting the arms and supporting them?

Finally, does the answer to those questions also apply to removing a spool, or relief valve if that became necessary later?

If anyone was wondering why, it looked like the best thing to check firet for bucket tilt drop under load, where it also drops when you first begin to try to raise it. It also has a fun problem with the arms where they sometimes come crashing down full speed, but I'm still replacing bushings on the linkage to tighten that up before digging into anything else.

Put the arms up, used the Lift Arms Support Device (orange/red) to block your lift arms in the air. Make sure to take any attachment off before doing that.
I would drain the hydraulic tank, just because it is better to work with.
You will loose around 1 gal to 2 gal of fluid.
Your "fun problem with the arms crashing down" might be you activating the float option on the foot pedal.

 

[rkenshin1]

Thanks, that's what I was hoping to hear.

I thought that float was a possibility but the way the pedal is acting stuck, I can't exactly tell what's happening yet. I need to get a new bushing on the crossarm pivot beneath the pump and get slack out of the linkage at the spool still. I mean, hopefully that fixes it, but I guess I learned to be pessimistic on these projects...

Thank you for the info!

 

[Markle]

I think you’re on the right track checking replacing poppets first. I had same issue of momentary drop upon lift pedal push. Buddy’s bobcat service in Milnor ND had parts. Great guy!

 

[Robanybody]

Hi All!

I've found this forum to be a wealth of information for the first skidstee I've ever had, and only for a few weeks now.... Hopefully I can actually help someone else out in the future.

My question - I have to check, clean and possibly replace the tilt load check poppet valve... What I don't know is, how much oil will drain out once it's open? Should I be emptying the hydraulic oil tank first? If it's significant, is there a way to limit it, like lifting the arms and supporting them?

Finally, does the answer to those questions also apply to removing a spool, or relief valve if that became necessary later?

If anyone was wondering why, it looked like the best thing to check firet for bucket tilt drop under load, where it also drops when you first begin to try to raise it. It also has a fun problem with the arms where they sometimes come crashing down full speed, but I'm still replacing bushings on the linkage to tighten that up before digging into anything else.

I use a specially adapted hyd tank cap. I've modified one to attach to the hose of a shop-vac. It keeps negative pressure in the tank and allows the hydraulic system to be opened with minimum loss of oil. Watch this video for the basic approach. I would go so far as to recommend changing the lift spool seals while you're in there.
Good luck