I have a 931b that developed a hydraulic leak. Found it the other day when it was parked. Slow drip on the right rear side that is running down onto the bevel gear case. It is plumbed for a backhoe attachment. Can't see where it is coming from, so today I started taking off some parts so I could see down on top of the steering clutches. First thing I removed was the side cover on the lever consol with the valve body under it. Everything there was dry. Continued removing parts. Got it to where I could see somewhat better. It's wet on the right side. Right now it appears to maybe be the aux hydraulic line for the hoe attachment. Doesn't seem like it was spraying, just a drip. Can't see yet where it is actually leaking. My first question is: Can I plug off the two ends of this aux hydraulic line, if that is what is leaking? The one end I can get to fairly easy where there is a 90° elbow fitting. The other end.... not so easy. Looks like it runs over towards the control valve. Second question: Does anyone know if I remove the sheet metal from around the levers if I will be able to plug where this line goes into the control valve?
I seem to remember the lines had to be connected together with the hoe off so plugging in not a good idea
Pittsburgh cat man, thanks for the reply. My thoughts were if the machine wasn't plumped for a hoe, wouldn't the port on the valve body just have a plug where the line goes now? Only problem is I don't know yet where the other end of that hard line goes. Other than towards the front of the machine. So,not sure. I assume that it would possibly be the supply side for the hoe. IF it only supplys oil to the valve body for the hoe. What would be the harm in plugging it off? Or maybe plugging it off would cause it to act like it was 2 blocked?
I remember the ones with a backhoe ones having a different pump I think you would be farther ahead to fix your leak
Yes, the hydraulic pump makes more pressure. Well, since I don't have a hoe attachment, I was looking to eliminate the whole line and by doing so. Eleminating a source for future hydraulic leaks. Plus that is a very long hardline. Not sure if it would be even available and probably cost $500+ if it is even available. I am going to reach out to Welder Dave. He was trying to add the backhoe power beyond lines to his 931. Hopefully he will have some input. Thanks for the insight. Appreciate your time.
I've seen a lot of brazed lines
This is the loader control valve out of a 31b with no hoe. Under on of those 3 plugs theres either a internal plug or one is made to plug a passage way witch ill tell you here in a bit
Take this plug out it will be facing downwards
Remove the plug up in that hole its right about where im pointing. Then reinstall the external plug and remove and cap your power beyond lines.
Just had a thought. It may be possible to come out of the valve body with a line and connect back up to the other part of the line at the 90° with a much shorter line. So, the hydraulic oil would still be flowing in a loop. Do you know of any businesses that make hardlines? Thanks.
Tyler, thanks for the reply. I am wanting to do away with power beyond lines completely. Am trying to figure out what all needs to be done. I will look at my machine tomorrow and try and figure out exactly where you are pointing. Thanks for the help.
End of the control valve facing out the right side dont you have my phone number if you get stuck give me a call
Tyler, if I had your number. I do not have it now. You can text me at this number and when I get around the machine, I can call you. 304 830 2730. Thanks
UPDATE: Removed end of Power Beyond line that connects to the valve body. It would be impossible to remove without taking it apart at the various fittings which just wasn't happening. Once the fitting was off at the valve body, I cut the line with my grinder. Ended up having to make 3 cuts to get the pieces out of the lever tower. That was the leaking line. Had rusted out where it was laying on top of the steering clutch box. Once it was all out I moved to the other side and cut that side off as close to the 90° that turns that line down to run towards the front of the machine. Tried to get that short piece of line out of the 90° with no success. Will try something different tomorrow. Does anyone know where that side of the Power Beyond line goes? Thanks
My 931B came with a hoe from the factory. Backhoes from the factory came with an optional piston pump for more flow (26.5 GPM, same pressure) at least the later ones. I had the main steel line (for the backhoe) from the valve that snakes under the hyd. tank and then across the back of the bevel case to the left side quick coupler get a leak because it was rubbing on a clamp. It had been worked on before. There was no way that line was coming off in one piece without major disassembly. It's about 7 feet long! I used a small hacksaw to cut the line a few inches after it bent to go alongside the hyd. tank. I kept the complex bent part of the line that went on the valve and had it flared at a hyd. shop so I could attach a hose to it. I ran one hose to the back of the hyd. tank then used another hose with a 90 to go across the back and I had the other end of the steel line that fits on the clamp and attaches to the quick coupler flared to fit the hose. I used compact hyd. hose because it has a smaller OD. It was only rated at 2250 PSI but I figured hyd. hose has a pretty good safety rating to handle an extra 250 PSI. I could see where someone had O/A welded one of the steel lines on the valve in the past when I had all the covers off. Without the complex bent section, I don't think you hook up a hose to replace it. It's a real spaghetti mess of steel lines on the valve to get a hose to fit. I also had the short steel inlet line to the valve get a tiny leak at a flare so had a new steel line made. It had some kind of weird bends too. Thankfully no more leaks around the valve or aux. lines. I do have some cylinders weeping though. Oh, I can't forget the main line from the pump to valve blowing apart because some idiot used non Cat hose with Cat fittings. They had pieces of plastic and even a metal tag wrapped around the hose to fill the gap. Had to lay in 60 litres of oil to remove and then again to replace it after struggling to get the belly pan off because the machine was sunk in soft ground. Couldn't pull the machine out because the backhoe stabilizers were down. I wouldn't be able to do these kinds of repairs now. Would be too hard on my body. About the only thing I haven't had to work on is the transmission. Knock on wood. The shop that did the engine said the screen was clean which is a good indicator the trans. is good.
I'm not at my machine to take a look. Can you follow the line or post some pics. of all the lines on the valve and point out which one you're talking about? I can take a look if I go out in the next little while. There should be a hyd. schematic though. AV Spares may show it. If not one of the Cat experts could post it. My backhoe is a 5G2150 fixed pivot. There was also a side shift backhoe but I've never seen one except for a pic. on the brochure. I'd guess the hydraulics hook up the same but not sure. It's a mess of hyd. lines at the valve though.
A good hydraulic shop could make a steel line but it might depend on how tight of bends you need. Cat can make much tighter bends. I was lucky a Cat dealer had one the stabilizer lines from the valve in stock. It was bent too tight to have one made and a hose wouldn't have worked. I used hose on another one because it was about 1/3rd the cost. You might want to use a hose so it has some flexibility for hooking it up.
My intent was to eliminate the entire Power Beyond hydraulic loop and circuit, plus related hoses. As you know that entire hardline is as crooked as a snake and extremely tough to access and impossible to remove in one piece. This section here would not be very difficult to work on, but it was not where the leak was. Below pic: hardline where it makes a loop just below the radiator fan.
Good for you in finding a work around fix on your machine to repair that line and get your machine working again. Kudos to you on that one. I would agree 100% that field repairs are not fun. Plus the oil you were dealing with made it even more miserable. I also agree with (me now being 70) as we get older that kind of work gets tougher.
Sometimes you just have to do the miserable repairs.
LOL. Yes, anyone that has worked on equipment has those kind of stories. Thanks for you input and teaching me that a work around can be done with hoses instead of those hardlines with numerous bends. Take care.