M59 no go

[D&D]

I’m selling my L48. Purchased the M59 with fingers crossed. I knew it needed some cosmetics but did not know of the overall hydraulic system?
I’m waiting to hear from them on it The stabilizers had great power, as did the boom stick and bucket . I don’t know if maybe I’m looking at one pump? I’m ordering a shop service manual so maybe I will be able to stay on things in a proper way.
From your posts you may be a service tech also? Any input is helpful.

Just a guy that’s too nice to say no and almost always gets stuck with stuff someone else did not know how or didn’t want to bother with. Sometimes we get so wrapped up in the “what’s wrong“ side, we don’t look at the “what’s working” side. Often enough, it’s something we did and forgot about (move a lever, snagged a tree branch, unplugged a sensor). Just part of human nature.
I will say this much about someone who had a l48 and now has a m59, you can bend the lower 3 point arms

 

[rScotty]

Tech said bad connector- replaced. Makes perfect sense due to how it pulled up lame. I had replaced the throttle control sensor so the tech guy dialed it in.
May need new pump? The power steering, BH swing and loader arms are weak? May be the one pump?
I don’t know the circuits on it yet?
Any thoughts on it?

The M59 has a total of 4 hydraulic pumps, two hydraulic filters, and separate relief valves for each circuit. Each circuit has slightly different relief pressure settings. Pressures would have to be way out of whack before you would actually notice any difference in normal power.

The power steering, BH swing, and loader arms are all on different pumps... but share a common filter.

The HST has its own pump and it's own special finer micron filter but shares the same sump tank with the other three pumps. Basically that means the HST is working as a bypass filter for the entire system.

The two hydraulic filters are on a 200 hr. replacement and cost over $120 for the pair. Pierce & drain the old ones to avoid a mess when unscrewing them. Check the pipe nipple that the filters mount onto to make sure it is tight in the transmission block.

The workshop manual goes through where and how to check the hydraulic pressure. Amazon has pressure-checking gauge kits. Make sure the kit has the right adapters.

Hydraulic troubleshooting: first check for plugged filters, then for suction air leaks between sump and pump.
Luck,
rScotty

 

[D&D]

Hydraulic troubleshooting: first check for plugged filters, then for suction air leaks between sump and pump.
Luck,
rScotty

you kinda lost me here. Guage readings or filter swap?

 

[rScotty]

I

you kinda lost me here. Guage readings or filter swap?

I'm retired, so I have time and have done a lot of this. I'll be glad to write you a complete test procedure if you want to give it a try yourself.

But the quick answer is it doesn't matter. If you have gauges, hook them up to the IN port of your loader control valve and take readings when the loader is lifting it's hardest, not moving, and the relief valve is making noise. That tells you if the system is meeting its specs.

If not, then changing filters is the first step in a series of simple diagnostics. Unfortunately, it usually isn't the filters. We change the filters because there isn't any way to test them, and because changing them could make a difference, and we were taught to do so.... and so we do it. And maybe it will work.

Or, you can just swap the filters instead of using the guages, but all mechanics have the gauges so we tend to do that first. It is simple, clean, and puts labor money into our pocket instead of filter money into the owner's pocket. We know we have to use the gauges anyway when the filters don't help... and on the M59 those filters are a hassle, hard to get too, often stuck, messy, and cost a lot.

BTW, a guage kit costs roughly HALF what the filters do, so one use pays for itself. And no worry about spilling expensive hydraulic fluid.

All rules have exceptions, and some tractors have a cleanable screen crud filter down inside the transmission. If it has one, often that IS the problem with their hydraulics. Those things clog a lot and nobody ever cleans them as they should. But your M59 doesn't have that screen.
Over to you,
rScotty

 

[D&D]

BTW, a guage kit costs roughly HALF what the filters do, so one use pays for itself. And no worry about spilling expensive hydraulic fluid.

All rules have exceptions, and some tractors have a cleanable screen crud filter down inside the transmission. If it has one, often that IS the problem with their hydraulics. Those things clog a lot and nobody ever cleans them as they should. But your M59 doesn't have that screen.
Over to you,
rScotty

Thank you for the good breakdown of your process. That cleared things up, at least for me.

 

[yarg]

Update:
After a visit to service guy he said 1-the main relief valve was over 1,000 psi out of setting. 2-the swing relief is being replaced as it was not operating. 3-the remains of a seal where removed from fluid reservoir (no idea of where it came from but had a wide profile and small expanded lip and felt like hard rubber)
Waiting for parts before further testing.
Still holding breath?

 

[rScotty]

Relief valves are brutal things. They vibrate and make noise. That's partly the way they are built and partly so the operator will notice and quit doing whatever is causing the problem.
They also heat themselves and the hydraulic fluid a lot and quickly.

Between the pounding and heat, a relief valve has a limited life. If someone just ignored the racket, there's no doubt that it wouldn't last long. So bits and pieces are no surprise. The good news is that there is a lot of filtration in that hydraulic system. The HST has additional fine filtration.

 

[yarg]

Sure hope that filtration protected against more damage? I should hear from them this week on what is happening? I’m just hoping they find the issues. They are easy fixes and the unit will perform as it should?