Just found site yesterday,Thanks already! My 632 left side will not operate forward or reverse.Thanks to this site I found & removed inspection plate & chains are intact.I also found the brass filter in the port block.There isn't a spring & the brass piece did not come out easily so I didn't force it.Are they usually hard to get out? Also, when I removed the hose from the block a lot of water ran out of the port.Does this sound normal with the problem I'm having? Any help would be greatly appreciated,Scott
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ooh dear, there should NOT be water in here. The bronze filter is a little snug, i used a pair of pointy nosed pliers to grab the end of the filter and pull it out.
If you have water you may have a serious problem. What colour is the oil? is it milky white?
If you have water contamination it could be all through your system, this will destroy your bearings and if left too long will damage your pumps.
Does your hydraulic reserve tank have its cap on?
For your sake i really hope what you thought was water really isn't, as if it was you have a lot of work to do......
It could be a stuck relief valve in the pump causing lack of drive or the water may have damaged your motor causing it to lock up.
I hope you get it sorted out easily.
If you have water you may have a serious problem. What colour is the oil? is it milky white?
If you have water contamination it could be all through your system, this will destroy your bearings and if left too long will damage your pumps.
Does your hydraulic reserve tank have its cap on?
For your sake i really hope what you thought was water really isn't, as if it was you have a lot of work to do......
It could be a stuck relief valve in the pump causing lack of drive or the water may have damaged your motor causing it to lock up.
I hope you get it sorted out easily.
Yes the oil is a milky cream sort of color.I'm sure it was water that ran out.I'm guessing about a quarter of a cup?The hyd cap is on.How can I determine if the relief valve is stuck?
The relief valves for the drive will be near where the hoses attach to the pump, they will be behind the plugs that are screwed into the pump body. Basically the middle section of the pump is where the pressure is generated. One side is the charge pressure relief valves, the other is the high pressure ones, set up 5,000 PSI.
If your oil is milky you really need to drain all your oil! you will need to fill and dump it a few times. The water may have even rusted the pistons in the rotating group in place, that would also give you no drive on one side. I can't stress it enough, oil in s hydraulic system WILL cause damage if you don't get it clean, and fast. There are a lot of close tolerance parts that move, without the lubrication of the oil they will wear out quickly.
Worst case and your pump is dead, all is not lost. You can get a re-co pump for around $1,800 USD. Motors are about $600 USD each.
Thank you, I'll drain oil tommorow.Also,when I had the inspection cover off I cranked the engine & tried the left side.When I did the right side motor started as soon as the left lever was worked in either direction.Does that make sense?Thank you again,all advice is appreciated
skidsteer.ca
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Sometimes when you push one steering lever the otherside will try to move. That does not sound to uncommon. Get the old oil out asap. I'd even try to drain the hyd cylinders by unhooking the hoses and pins and moving them in and out. New filter, unhook the cooler and blow it out with air. Anyplace you can upen the system and get some oil out.
The more old oil you can get out the less # of times you will have to dump the new stuff that you put in. I went through this on a skidder. Rinsed with diesel, started and cycled the cylinders , Dumped filled with oil 3 more time b4 the system started looking clean. This was a basic gear pump hydraulic sytem, I don't think I'd do the fuel think with a skidsteer hydro pump.
Ken
The biggest issue i see with water, the oil gets like clumpy too almost like grease. You really need to get it out...
I hope it all works out well for you.
skidsteer.ca
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Tazza
Yes the oil gets vary thick, pudding like chunks in it. If he seen some actual water it also sounds like the oil has become saturated with water and can't absorb any more. This is when rusting starts. Also the wear protection on straight water must be severely compromised.
Ken
Finally got someone with some mechanical skills(unlike myself) to take a gander at my dilema.He thinks one of the drive brake disc is broken.One is clearly broken free and flopping around.The other is attached but still pretty loose.I assumed these were parking brake disc' but my mechanic thinks they are steering/drive brakes similar to a track loader or dozer.Is he on the right track?Again,I appreciate any & all advice.
The brake discs are meant to flop around. They are held on a hexagonal shaft with a large sir clip. This is so they can essentially float to get in the correct position. They have NOTHING to do with steering, only for the park brake.
All your drive is controlled with the big blue pump your steering levers attach to. This is a variable displacement piston pump that is fully reversible. Essentially your motors are attached to the pumps output so when you vary the amount of fluid the pump generates this in turn spins the motors at that speed. If you move the stick the other way the oil flow actually changes direction which makes the motor spin that way too. Seeing a diagram for this sure helps explain things.
The chaincase only transfers power from the drive motor through a reduction box to the wheels, it also has the park brake. All the drive power generated between the pump and hydraulic motor.
If it was my machine, as you said the oil was white and water came out. I would pull the pump and clean the insides out and make sure the rotating groups are still ok. If the pistons are stuck or the swash plates are worn this will cause a lack of drive. Really the motors should be pulled and cleaned as well. This is all up to you though. You may get away with dropping the oil several times to clean the system but as you said your drive on one side is not working I believe you have a pump issue. You can swap motors from side to side to confirm this, if the problem moves its the motor, if not its the pump.
Hopefully you can get out of it cheaply.
Makes sense to me,I guess I was hoping to get away without pulling the pump.Looks like a major undertaking to me.Thanks again & I keep u posted.
sterlclan
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on this machine it "may" be easier to swap hoses on the pump both sides front to back this will make the handles backwards and on the wrong sides but would tell you if it is the pump or drive motor . if it is like my 630 the nut that holds the sprocket to the drive motor is a bugger waaaaay tight. they really aren't that tough to repair just time consuming.....good luck ...Jeff
I keep assuming its the same setup as my 731 and 743..... You simply un-bolt the motor and it slides out. I know there are a few models that the end is bolted internally.
Found two problems today.#1 hydraulic oil tank cracked around the filler neck under the vented cap.This explains the water in the fluid.#2 The keyway on the end of the drive motor is sheared off & shaft is able to spin freely without engaging sprockets.Thank God for your site & help or I would probably be paying the "mechanic" to replace my "drive brake."I'm going to start re-assembling tomorrow & changing all fluids.Thanks again.
sterlclan
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make sure to get the nut on the shaft tight... I used some locktite if it has any slop it will eat the new key quick.nice to hear that it is something simple....Jeff
Thanks,the nut had backed all the way out against the nut on the other side.I figured thats what caused the key to shear.
If it is the sprocket retaining nut, that gets tightened to 300 ft lbs on the 632.You are supposed to make a tool from a old brake disc to hold the shaft while tightening. I doubt that very many people have a old brake disc lying about though.
May be a stupid question,but where is the drain for the chaincase oil? The plug on the front looks like the fill level to me.I may have overlooked it but I never found it.Tks
There is no drain for the chain case. You can suck it out the fill hole in the front or better yet take off the forward inspection cover under the parking brake and suck it out then wipe it out as best as can. I have read on here of some guys drilling a hole and welding a fitting on the lower front for a drain and that seems like a good idea to me.
