M59 steering loss

[Russo52805]

We have owned a M59 for about two years now and for the most part light duty work out on the family ranch. Last time when going to park the tractor i noticed that i was having to turn the wheel many times to get it to turn. by the time i got it back to cover i had almost no steering at all had to turn using the dual brakes. With the tractor off the wheel will just free spin not turning front wheels when running same thing even with it reving to 2500-2600 rpm. the only way i can get any movement is by lifting the front wheels off the ground with front bucket. All other hydraulics seem to be working fine. (backhoe, front bucket and front remote hookup we use for a grapple) I order the Service manual but it dose not have much information in the steering section. (section 7) Any input would be greatly appreciated. Thanks in advance, Wes

 

[AllDodge]

Check the fluid level and color. If its good crack one of the lines (wear safety glasses or shield) and see if oil is clean and clear.

 

[Russo52805]

Fluid level is full in The front axle and the rest of the hydraulic systems work at full capacity.

 

[AllDodge]

The front axle lube is not connected to the steering.
Understand the tractor hydraulics are working fine, and the pressure from the tractor hydraulics are sent to the steering box. Assuming the fluid level should not be causing this issue but want to rule things out.

The steering control allows fluid to pass/pump to the steering cylinders as the wheel is turned. So if no fluid is making it to the box, it doesn't work. So either there is a clog, no or not enough fluid, or something is broke or disconnected. Maybe the steering coupler came off, the one between the wheel and box. Its like a universal joint.

If things are connected then crack a steering line (use safety glasses) and see if fluid is seen and not full of bubbles

 

[Russo52805]

I know the coupler is good checked that this past weekend I won't be able to go crack a line lose until this weekend so I guess I'll have a update after that. Thanks

 

[oosik]

My thought - one of the hydraulic hoses to the steering box is no longer connected. OR, one of the hoses is cracked and blowing fluid. Be very careful - hydraulic fluid, under full pressure can cut like a surgeons scalpel.

 

[Russo52805]

There are no external oil leaks that I can find. Even parked over cardboard no drips found overnight

 

[rScotty]

There are no external oil leaks that I can find. Even parked over cardboard no drips found overnight

The M59 has several hydraulic pumps which all get their oil from a common sump. The tractor hydraulics can be working fine, but all that means is tht there is sufficient hydraulic oil in the sump. It that doesn't necessrily mean that the power steering is getting pressure, because the steering pressure is generated by a special power steering pump and not by the tractor's main hydraulic system.
First thing you need to find out is if there is any pressure getting to the the push/pull steering cylinder up by the front axle. To do that, you will need to make up some sort of hose fitting so that you can read the pressure in that line. Often its a short piece of hose with a gauge on a hydraulic "T" in the middle. Your local hydraulic shop can make up that tool for about $100. It needs to handle 2500 psi; a 5000 psi gauge is a typical size and will work. Secton 7-S3 in the workshop manual describes a gauge setup that will work and can also be used in other places for setting relief valve Popoff pressure.
The workshop manual has pretty good coverage on the power steering system....better than most.
First find out if you have pressure. Then we can figure out what to do from there.
rScotty

 

[rScotty]

We have owned a M59 for about two years now and for the most part light duty work out on the family ranch. Last time when going to park the tractor i noticed that i was having to turn the wheel many times to get it to turn. by the time i got it back to cover i had almost no steering at all had to turn using the dual brakes. With the tractor off the wheel will just free spin not turning front wheels when running same thing even with it reving to 2500-2600 rpm. the only way i can get any movement is by lifting the front wheels off the ground with front bucket. All other hydraulics seem to be working fine. (backhoe, front bucket and front remote hookup we use for a grapple) I order the Service manual but it dose not have much information in the steering section. (section 7) Any input would be greatly appreciated. Thanks in advance, Wes

I guess we really ought to check the simple things first.
1. make sure that your hydraulic oil is up to the proper level or at least close. It's checked via a dipstick back under the rear cover by the PTO. Mine is always hard to see the where the oil level is on that dipstick - it's clear oil on a shiny dipstick. So I blued the bottom third of the dipstick over the kitchen oven burner. That makes the oil stand out a little better.
Low hydraulic oil can certainly cause all of those symptoms even if the rest of the hydraulics work normally.
For instance, since the M59 steering circuit and steering pump are separate from the tractor's other hydraulics, the steering pump oil pick up point might be at a different level in the common shared oil reservoir.
2. Most of the steering components hook together with splined shafts so they can't really slip. Looking at the exploded diagrams in the parts book, it looks as though it would be possible for the steering wheel and steering shaft to lift out of the universal joint that connects that shaft to the steering control box. See pages G101 - G105 in the parts book. Pg # 120 & 122.
I think if that joint had slipped out you would notice that the steering wheel was able to be lifted up & felt wobbly.

It would be nice if the problem was something so simple. But I believe you also said that the steering would work when you lifted up the front end with the bucket? If so, you might want to repeat that and get some more information. Because if indeed the hydrostatic steering is simply too weak to move the wheels - and if the oil is up and the filters good - then it will be time to insert the pressure gauge into the line to the front steering cylinder so that you can do some more diagnosis.

If worst comes to worst and you do have to take it to the shop, you might want to check that the shop has a hydraulic flowmeter. I used to have a shop and not all shops have that tool - in fact a surprising amount of shops don't. But it is the one sure way of telling if you are dealing with a repair shop that understands hydraulics or not. If they don't have a flowmeter, consider going to a different shop. A tractor shop trying to do hydraulic work without a flowmeter is sort of like an electrical shop without a VOM.... or a machine shop without a mic. Go somewhere else.
rScotty

 

[mikester]

Tractor Can Not Be Steered
Steering controller malfunctioning - Replace - 7-S6
Steering linkage broken - Replace

Hard Steering
Steering linkage bushings sticking Replace
Hydraulic pump malfunctioning Replace 7-S7
Overload
Transmission fluid improper or insufficient Change or replenish G-9
Oil leak from hose joint Retighten
Insufficient tire pressure Inflate G-54
Steering controller malfunctioning Replace 7-S6
Relief valve malfunctioning Replace

 

[Russo52805]

This past weekend we had the time out at the land to pull the steering ram out of the tractor. When disassembling the center seal was completely trashed (multiple pieces fell out). Brought the ram home and rebuilt and hopefully will have time next weekend to go out and reinstall. After not have the tractor for a month would be nice to have back in service. Thanks y'all for the input. Wes

 

[rScotty]

Well that's interesting Russo. It sounds like you found it. I'm glad you used your common sense and not any of our advice..., cause we were all wrong!
But that still leaves me curious what led you to suspect the steering ram. It seems like an easy and obvious place to look in hindsight, but nobody suggested it. For my part, I figured that the ram was doing its job when you reported that the steering was normal if you used the loader bucket to lift the front end off the ground. To me that left insufficient pressure as the most probable culprit, But now I can see how it could also be the steering ram cylinder having not enough internal seaing.

I guess I should say that we would have gotten there eventually with a pressure gauge once we found that we had good pressure at the front, it would have had to be either the ram or the steering controller's bypass valve and those are then easily checked with a simple crank of the wheel to lock. But what led you right to the steering ram? Or was it just the easiest thing to get to? Or luck? I don't think I've ever even looked at the steering ram on mine. You can bet I'll eyeball it today.

Hmmm..... I just went back through the Kubota M59 Workshop manual and re-read the section on steering. Kubota doesn't mention any tests specifically for the steering ram, and their steering trouble shooting diagnosis page doesn't even mention the steering ram. But of course their lack doesn't excuse my own.

Well, OK,,,,, the good news is that a steering cylinder rebuild is straightforward and probably the easiest thing it could have been. Do you have any idea what caused the center seal to go bad? Steering ram cylinders are pretty common, and I've rebuilt a number of leaky ones, but haven't seen any I recall with an internal seal go completely bad.

Thanks, and please do keep posting as you fix it.
rScotty

 

[Russo52805]

Well that's interesting Russo. It sounds like you found it. I'm glad you used your common sense and not any of our advice..., cause we were all wrong!
But that still leaves me curious what led you to suspect the steering ram. It seems like an easy and obvious place to look in hindsight, but nobody suggested it. For my part, I figured that the ram was doing its job when you reported that the steering was normal if you used the loader bucket to lift the front end off the ground. To me that left insufficient pressure as the most probable culprit, But now I can see how it could also be the steering ram cylinder having not enough internal seaing.

I guess I should say that we would have gotten there eventually with a pressure gauge once we found that we had good pressure at the front, it would have had to be either the ram or the steering controller's bypass valve and those are then easily checked with a simple crank of the wheel to lock. But what led you right to the steering ram? Or was it just the easiest thing to get to? Or luck? I don't think I've ever even looked at the steering ram on mine. You can bet I'll eyeball it today.

Hmmm..... I just went back through the Kubota M59 Workshop manual and re-read the section on steering. Kubota doesn't mention any tests specifically for the steering ram, and their steering trouble shooting diagnosis page doesn't even mention the steering ram. But of course their lack doesn't excuse my own.

Well, OK,,,,, the good news is that a steering cylinder rebuild is straightforward and probably the easiest thing it could have been. Do you have any idea what caused the center seal to go bad? Steering ram cylinders are pretty common, and I've rebuilt a number of leaky ones, but haven't seen any I recall with an internal seal go completely bad.

Thanks, and please do keep posting as you fix it.
rScotty

I wasn't having any luck getting the pieces I needed to to adapt a pressure gauge in the rule area we are located in so with that someone on orange talk forum had mentioned it will the gave a list of possible causes. When you could get it to go to lock it would hold. When we disconnected the hoses and turned the wheel with the tractor off it would pump fluid one way or the other so it should have been turning the wheels when connected but would not. So figured the problem to be in the ram. Also with many years of turning a wrench I've found the most manufactures tend to be vague on areas of less expensive repairs so that more money can be made on diagnostic time. Also never been afaid to tear something apart. I figured if everything check good I was only out $150 for the seal kit and at that point I know the ram was in good condition. My only guess as to why it went bad is the heavy rental use it got before we bought the machine.

 

[rScotty]

I wasn't having any luck getting the pieces I needed to to adapt a pressure gauge in the rule area we are located in so with that someone on orange talk forum had mentioned it will the gave a list of possible causes. When you could get it to go to lock it would hold. When we disconnected the hoses and turned the wheel with the tractor off it would pump fluid one way or the other so it should have been turning the wheels when connected but would not. So figured the problem to be in the ram. Also with many years of turning a wrench I've found the most manufactures tend to be vague on areas of less expensive repairs so that more money can be made on diagnostic time. Also never been afaid to tear something apart. I figured if everything check good I was only out $150 for the seal kit and at that point I know the ram was in good condition. My only guess as to why it went bad is the heavy rental use it got before we bought the machine.

Well, sure... loosening up some ram hoses and then turning the wheel with the engine OFF is a is a dandy way to get another piece of info about pressure to the ram. Just curious....did you also try it with the engine ON?? .

Anyway, what bothers me is this.... How could anything have damaged the center seal in the ram? It happened, so we know it's possible. But WHY? I just hate to fix something without understanding why it went wrong.
So I've been trying to figure out what could cause the center seal to get damaged.... what are the possible culprit? Even used as a rental with cowboys acking the wheels around against obstructions I can see where that would beat up exterior things, but not the inside of the ram. ... OH! the light just went off... Exterior things.... Hmmmm.... maybe the steering stops? What if the steering stops got beat up or are way out of adjustment?

Because when the ram is doing normal or even really hard brutal steering that center seal never does contact anything solid that would cause the center seal to break. All that part does is just moves back and forth pushing and pulling on the ram rods. And when the steering goes all the way to one way or the other, there should be some sort of positive steering stop to take the stress first so that the center seal of the ram doesn't come up hard against the inside of the ram. Usually a steering stop is built somewhere on the steering knuckle and is something like an adjustable bolt that limits the movement of the steering knuckle by stopping it against something solid. Sometimes against the front axle case. I was going to go look at mine, but can't see mine in the deep snow today. But there has to be some sort of positive steering stop so that the cast iron knuckle and axle take the stress against the stop before the center seal in the ram gets to the limit of its internal movement.

I'd recommend you take a look at the steering stops. Check to see that the exterior steering stops are in place - whatever they are - and working to protect the rams center seal from traveling too far. The adjustment is described on page 6-S6 in the workshop manual....but kubota's text doesn't make much sense to me. Anyway, that's what I'd check. I can't think of anything else that would let the ram damage itself like a missing steering stop would.
good luck, rScotty