Long story short I ended up getting a 235b if I can get it out of the woods. The machine runs and operates however from what I’m told the machine has an issue with one of the final drives. From what I’ve been told the final drive leaks/pours fluid out of the final drive vent tube when you track the machine. It’ll track, but it’ll spill fluid all over while doing it. I’ve read around a bit and it seems like there’s a low pressure line that charges the brake release and releases the final drive brake. Is it possible said brake isn’t releasing all the way and is somehow overheating the drive causing it to puke? Any and all advice is appreciated. Thanks!
Good day If it is one side plug the lines and walk it out using the equipment, the final drive only has a small amount of oil so from your thread it is more probable it is a failure of the drive motor. You could remove the offending unit and take it to a repair shop, be sure to change the filters after the fix. Kind regards Uffex
This sounds fixable. You could pinch off the brake line and see if it stops the oil leakage. At least it may eliminate that as a source.
Highly unlikely. If the brake on the other side is releasing and the other side doesn't spew oil everywhere then they both should be releasing OK. I'm with Uffex, it sounds most likely as though it's a travel motor seal blown. How far do you potentially have to walk it to get to where you will (I assume) be loading it onto a lowboy.? Oh, and post a Serial Number. It makes it easier to find technical info.
Im sorry, you’re correct. I meant to say it’s leaking oil from the drive motor. You have to add hydraulic oil to the machine because it’s leaking out. It’s in a tricky spot to walk it out with a track down. I’m sure it’s possible but if possible I’d like to fix it and then just walk it out. The machine is located about half a mile up a really steep roughed in driveway with multiple switchbacks. Could probably track it out with one track but not as desirable. It’s been sitting there years so I can fix it where it sits and then track it out. Yes it’ll be getting lowbedded out of its current location. Is there anyway to narrow down what’s broken on it? I’ll get a serial number off it later.
Do you have the necessary pressure gauges and testing equipment.? So if I understand you correctly, to move it downhill for a half mile distance I would:- 1. Disconnect and plug the main hoses at the defective travel motor leaving the smaller case drain, 2-speed (if fitted), and park brake lines connected. 2. Disconnect the defective final drive. This can be done mechanically but I'd like to confirm the S/No to correctly identify the procedure. 3. Walk the machine out using one powewred track, freewheeling the other one, the swing function, and the bucket. That gets the machine somewhere you can work on it in relative comfort. The other option would be find a replacement travel motor and swap it out with the defective one. Then you could walk it with both tracks. It may be (and likely is) something far worse than just a seal in the motor that is leaking. Seals usually fail as a result of something. Assume the motor is well trashed internally and you probably will not be too far out.
Here are the guts of a typical a 235B travel motor. Without the S/N I can't tell if it is the same as yours or not because there is more than one type of motor depending on machine Serial Number. The oil leak is most likely coming from the seal #17 (circled), but the root cause could be one or both of the bearings #15 or 16, or even something else further inside the motor in the area circled on the RH side. I guess your other option at this point if you want to travel the machine out using both tracks is to remove the leaking travel motor and get it to a shop where it can be disassembled and its condition assessed.
Thank you. I’ve attached a picture of the S/N. I’m going to get some hydraulic fluid and batteries and get the machine running to see where it’s actually leaking fluid from and go from there. I appreciate all the help so far. I pulled off the cover for the final drives and this machine has 4 hoses going to it. Three to the main part of the pump and one to the center section which I’m assuming is the brake release line. I’ll remove that line and see what kind of pressure that line is getting or am I wasting my time there? I’ve also attached a picture of the machine.
Unless you have a tee and a gauge to actually measure what is the pressure in the line I would say you are wasting your time. OK, so no 2-speed. The 2 large & 1 small going to the same area will be for the motor FWD & REV drive (2) plus the case drain (1). From the machine Serial Number the illustration below is your travel actual motor, This is an older type of motor that is shown on the system as being discontinued and I have no idea if repair parts are available for it. It still has a lip-type seal (#27) that is probably what's leaking, but probably as I mentioned before the leak is most likely as a result of a problem somewhere else. In view of what type of travel motor you have my suggestion would be to remove it and get it somewhere where it can be disassembled and evaluated, Then cross your fingers that whatever parts are required to repair it are still available. The complete motor is Part Number 4T-3068 BTW.
A very simple test for hydraulic motors is a casedrain flow test and can give you a very good idea of the condition of the motor. By putting the casedrain hose into a pail, lock the track so the motor is stalled, run the engine at wide open throttle and fully active the track lever and hold it there for 1 minute then stop. Now measure the amount of oil in the pail. More oil equals more damage. You do need to know what the flow spec before starting and if it's not available on paper then do the test on the good side.
There is no case drain flow spec that I can see so testing one side versus the other would be the only way to do it.
The usual problem with those is the seal surface between the piston barrel and the outlet plate being damaged from foreign material. Sometimes that can be lapped smooth but if too deep it will take new parts. I don't recall any brake release line in those. What I saw on those was the usual release by applying oil to move the machine. I also seem to recall the motor was on top and easy to access after you used a crane to move the cover/guard the covers up the back of the carbody. I also recall that if there is more than a few drops of oil coming out the case drain with the track blocked so it can't move, engine at high idle and and pressure held on the relief valve there is a problem.
According to the SysOp the brakes are released by pilot pressure. The brakes are separate to the motor, mounted in between it and the final drive. 1) Track brake line. (2) Left track motor. (3) Pump oil lines. (4) Pump oil lines. (5) Right track motor. (6) Track brake line. (7) Left track brake. (8) Case drain lines. (9) Right track brake. When the machine is traveling, turning or both, pilot oil flows through lines (1) to track brake (7) and line (6) to track brake (9). The pilot oil then releases the track brake allowing track motors (2) and (5) to operate.
On the final drive case opposite side from motor right in front of sprocket is a plug . Remove the plug and loosen the nut in and it will take the final out of gear as in no brakes. I believe the swing motor is the same as a drive motor. The right track has some sort of problem as it is way loose. Bob
I put two new batteries in the machine yesterday checked all the fluids and started the machine. It started within 10 seconds of cranking after sitting for probably a year. let it run for 25 minutes or so to warm everything up and ended up blowing one of the hydraulic lines when I picked the boom up. Going to get a new line made hopefully today and then see where exactly it’s leaking from and under what circumstances (straight tracking, stalling one motor to turn, etc) and report back. You guys are an incredible help. Thank you all so much. I’m excited for this machine. I’ll look into why one of the tracks isn’t tensioned later.
One more place it could leak is at 7 and 22 seals which would dump brake hydraulic oil into the final drive .
Yeah, that's why I said to pinch the brake line off and see if the leak slowed or stopped. It could be several things in there.
Ok replaced the line and tried to track the machine. Oil is pouring out a vent or something on top of where the final drive brake would be. It’s coming out of that piece with the two bolts holding that plate down on the left. so pinch off the brake line and see if it slows down? I’ve attached a picture of where it’s leaking from.
To me that looks like a parking brake seal has failed. If you can get the travel motor off removing the brake assembly should be fairly easy.
The problem if you do that is that the brake will not release if you attempt to travel the machine. For the purposes of a test you could remove the line where it connects to the brake and plug it. At that point if you move the travel lever the motor will not turn but at the same time if no oil comes out it will at least prove that the leak comes from the brakes.
Thank you! Those are really good Instructions. I’m going to go look at the machine later and see if it’s easier to bring another machine up there to lift the motor out or see if it’s easier to use a come-along attached to another part on the machine to lift the motors out. Thanks again!
Think I should see if these seals are available before I take it apart?
Swing the upper structure around so that the boom is directly over that rear LH corner and you ought to be able to throw a nylon sling over the boom on which to hitch your come-along. See the attachment. If you take the brake assembly apart I would suggest that you should replace everything highlighted in yellow - all the seals basically. You will probably find anything that has not failed is hard and brittle by now. Those items highlighted in blue you should check availability just in case you find them tired/damaged/worn out on disassembly and need to replace them.