BIG bummer!!! I fired it up this morning, found a large leak in the side of the hose from vane-pump to Control Valve. I think I can change that hose without disturbing anything else (except oil level, of course); I'm going to try doing it "wet" without prior draining of any fluid. That is a weird hose, -8 fitting on one end, -12 on the other. It will be Tuesday before I can get another hose. And, "no", I don't think that was the original leaking problem. That hose has been dry until I started it up this morning. I had to bend that thing around to get it out of my way while working on the Control Valve, that might have "pushed it over the edge". At least all the linkage over there is well-lubed now... I sure wish there had been an easy way to spin the pump spline and pressurize the system while the engine was out!
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Gloriosky, it's DONE! ...sorta-kinda. I thought I had it whupped, once I was down to just that leaking hose. However, this beast lived up to its name and put up a spirited fight all the way. As promised, I ran out to the local Bobcattery for a hose at my first chance. We couldn't positively identify the hose in the IPBs, and none of the candidates were in-stock anyway. The parts guy showed me where to look for a P/N on the hose, if it was OEM, and also advised that they could make one "per sample" if necessary. I went home to remove the hose. The pump-end was easy, lots of access and took only about a minute. Better yet, I discovered that oil only gushed out of the pump fitting, which I quickly capped. The open hose just trickled the fluid already in there. The hard-to-reach end, back at the Control Valve, was a whole different story, took an hour or more! That fitting was very tight, it required the long cheater-pipe again, but it finally did loosen. Trouble is, the flats got rounded just a bit, such that the adjacent flats were buggered-up enough the the crowfoot wouldn't fit on them with out forcing it on/off clumsily with a long screwdriver. Also, the hose nut seemed to be distorted enough to be non-free-running. It was a tedious process of place the crowfoot, attach the ratchet, move 1/6th turn, then remove all and start again. Add in a few droppings of the crowfoot into the now-newly-oiled bilges, and removal with long tweezers (surgical hemostat, actually), and there you are. There was a P/N on the hose (on the non-visible end, of course), and the Bobcattery even had all the pieces to make it. The hose material was "non-stock", but they actually had a "remnant" just a few inches longer than needed! Yeah, but after that things took another turn for the worse. When I went to install the hose I discovered that the fittings, the hex size, was 1/16" bigger than the old one. No problem on the pump end, not only could I fit an adjustable wrench in there, but I have the needed 15/16" open-end wrench. The other end, though, meant I no longer had a crowfoot that fit. That would be a 2-day and $25 online order. Frustrated, I went ahead and made a crowfoot out of aluminum, took an hour or so. Using that, I got the hose back on, but still a very tedious one-hour process. This time, I found that the crowfoot had to be placed, then the extension attached, then the ratchet... for each flat-turn. The new hose still did no free-run on those threads. Either the old fitting (on Valve) was distorted/corroded or the threads in the hose were not quite right. Maybe a close metric "equivalent"? I tightened that fitting as tight as possible, until the aluminum crowfoot start to give, then fired-up the engine and found no leaking. I have a good crowfoot on order and will tighten that hose better tomorrow, but was able to exercise all the hydraulics and things now look good. I will post again in a few weeks, after some run-time on that Control Valve with the lip-seals instead of quads. In the meanwhile, my thanks to all that helped me here, especially OM for the IPB and FSM
My apologies for that long "run-on" paragraph. Trust me, I did have it formatted to be a bit easier to read. Yeah, I know there is some way to change my user settings to allow retaining formatting, but I am much better with mechanical/electrical issues than GUI nuances.
7LBSSMALLIE
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- Feb 2, 2012
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guys talk about turning mole hills into mountains. assuming this this a keeper not a pass on, A pull eng hr1/2. inspect u joint. clean rad and cooler. replace stat inputshaft seal. inspect ring gear. reseal control valve . perform thousand hr service. as in new hyd oil case drain filters new a/f new hyd fluid. change eng oil and filter and reassmble all . do not forget filter located on block by stat. can be cleaned.. this can be done in one day. BINGO. a 743 the most basic trouble free unit ever made..
First off, go into your profile and check the box that says use HTML editor, then your paragraphs will work.
You did a very good job, i have never replaced that hose with the engine and tube lines in place. Not sure i'd even attempt it.
I tried looking for that "profile" stuff (right-click on my user name, several different places) and can't find that HTML editor box to check. Like I said, I'm much better at mechanical/electrical operations than GUI navigation... A bit "off-topic", but a brief update: All looked good, although a little bit of leaking showed up after a short while of running. I couldn't tell where it was from, but figured it was from the front of the valve spools, as I was using a the lift/tilt a lot more than usual (moving 60+ yds of fill). Then I put the hydra-hammer on it and quickly blew the aux hose, back over my LH shoulder, at the top of the left lift-boom. I didn't notice this until the fluid level was so low that I no longer had control of the lift and tilt. Trying to back the B'cat out of the hole I was in, it tilted forward to a 45 deg angle because I couldn't position the hammer to minimize the effect of its considerable weight hanging out there. I was hanging on for dear life and the engine kept running until my wife could reach in and turn it off. I'm hoping no damage was done. We got it back "on its feet" and I will fill with fluid later today for moving out in the open for repair of that hose. The joy never ceases! Yeah, I know, that hammer puts a lot of jolt on everything; not the nicest tool to put on the B'cat.
If you look at the line that says home search profile logout click the profile button to edit your profile.
Sounds like you had a bit of excitement, hopefully no damage was done, you just need to replace the leaky hose.
Okay, I found where to edit my profile, thanks. I have no clue as to why I didn't see that before! Yeah, my excitement was increased because I hadn't yet fastened-down the cab/cage; so that tilted up and offered little of a secure hand-hold or belly-bar. It started up fine today, but the lift/tilt are kind of noisy (yes, I did put in a couple of gallons of fluid before starting it). I'm hoping that is just air in there and will clear up once I get it in use again. That bad hose came off relatively easy, so I should have the B'cat back in operation tomorrow. Did you notice that my "formatting" is still pretty primitive? That's because I could no longer type in the "reply" text box once I had checked that html thingy in my profile. I had to uncheck it to post this reply...
OldMachinist
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What internet browser are you using?
Using Firefox on Win8
Truly, I don't think the joy with this beast is ever going to end! After hammering on concrete for an hour or so, two new leaks have opened up, or at least become more obvious. One is at the base of the main relief cartridge. Either the O-ring there has failed or that thing is coming loose. It looks like I can actually reach in and unscrew that without too much hassle... let's hope. The other leak seems like it might be coming from the oil cooler. I'll dig into both tomorrow, after everything cools down.
No mystery about the leak at the oil cooler. I reached in with just the crowfoot in my hand and could move the nut on the hard-line on the left side. Apparently it loosened up from the vibration of the hammer. I'll pull out the exhaust flex-line tomorrow to get a couple of wrenches in there and "honk it down" tight. The main relief isn't such a clear fix. Although I saw fluid gushing out from around it, it wasn't loose and the O-ring shows no signs of failure. The only thing I noted is that the back-up ring for that O-ring was installed on what I consider to be the "wrong side". The back-up was on the pressure side of the O-ring. That's the way the FSM shows it, but not the way I understand that they work. I'll probably re-install the main relief with a new O-ring on the other side and see what happens. It's not hard to get that valve out, just takes a long socket extension.
Bad, BAD news. The cooler line was no problem, just awkward and messy. I could really find nothing wrong with the main relief, so started accepting that the leak might be from the spool just below it. I did have some slight hope that the leak at the cooler was running down that hard-line and just appearing at the Control Valve... but not so. With everything back together I fired it up and it now looks like the fluid is coming out the detent-cap on the lift spool. There is a little notch at the base of that cap, probably to relieve the inevitable slight leakage, and fluid is spurting up out of that notch onto the main relief. I did NOT take that detent stuff off the spools when I changed the spool seals. Does anybody know if there are seals in the detent that would cause external leakage like this? Can that detent stuff be removed with the spool in-place, so that I can change seals in there (and even rear spool seal) without removing the spool?
It can be done in place. You need to remove the linkages at the front where the rubber boots are, the spool will slide back and out. You will lose oil, but what can you do.
You can get a seal kit from the dealer or take samples to a seal shop to get matched. The job is not fun, but can be done.
When the cap comes off, be careful to not lose the balls and spring for the detent. If you remove the E clip from the alloy housing first, slide it off then be careful to slide the innder part off with your hand over the exposed spool/spring part to catch the balls. If any are lost the dealer have these.
The allen head bolts at the front can be hard to get out due to access, but it can be done all the same.
I should have updated this a couple of days ago, but have been waiting to put some run-time on it again. The lift-spool was leaking at the rear because I hadn't put the lip-seal in correctly. It looked both pinched in one area and "rolled" so the the lips were both pointing towards the OD, 90 deg. out of position. I might have been able to massage it back into shape, but I still had all the new quad-rings that were also in the kit, so used one of those. I did not touch the front of the valve, getting to ANYTHING there involves removing those hoses I am so fond of. For me, more than "hard to get out", impossible with the hoses in the way! Since I didn't remove the spool, *just* the detent parts, there was minimal fluid leakage. Plenty enough for me and my tools to be coated, of course, but not "buckets". I got the detent balls/springs out without losing them (slipped a paper-towel core tube over all when pulling), but lost-and-found balls several times out on the bench while trying to get the forward ones into the (big) spring cap. I have a good collection of steel balls, which is good, because I didn't find them every time they went flying! The rear detent balls/spring, that have to go in after the spring cap and detent plunger is back on the spool, would be impossible without a special tool. I don't think even that pliers arrangement shown in the FSM would work. I made something like a 2-piece shaft collar to hold those balls. If I had arms about 4-5 feet long this would have been easier, but it was, indeed, reasonably "doable". I'm sure hoping that one lip-seal failed because it was installed improperly, and that the other 7 will be OK! By the way, there are no seals in the detent parts, I was correct in thinking that could be left alone originally.
I used large cable ties to position the balls.
Lets hope it sll works as it should!
7LBSSMALLIE
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DUDE god bless youre heart. sounds to me like you got after it and stayed after till job was done. around thru over or under. IM PROUD . could use techs like you> ? now that the learning curve is over. how much time would quote this job at ?
Sadly, still no joy here. I used it for about 1 hr this afternoon, the front seal on the lift spool is now leaking (wasn't before). Now I have to drain the tank and take those two hoses loose on one end to bend them out of the way at the front side of the control valve. At least it is the top spool, and I still won't have to take the spool out, won't have to disturb the stuff (detent) at the rear. I don't know if this seal failed because the lip-seals just don't work, or because I horsed that spool back-and-forth too much doing the rear. I'm *dying* of curiosity to get the seal out and inspect it... Stay tuned! I tried the cable-tie a little bit, but wasn't really working for me, even out on the bench. Plus, it would have had to be robust enough to stay in place while I was installing the spring-cap and detent plunger onto the spool, reaching in and doing it by feel. Even if I could have got the cable-tie on, I wasn't confident it would stay on while I was compressing the spring, getting the thread started, and torquing the plunger tight. The "2-piece clamp" was a sure thing, so I took the time to make that.
When disturbing any seal, you really should replace it. They get hard with age.
With any seal that is not new, if you move it or interrupt it in any way there is the chance of it not working as it should.
The (now leaking) front seal is relatively new, one of the lip-seals that I recently installed. I didn't disconnect that spool from the linkage when I next change the rear seal, so figured the front seal wouldn't be see a sharp groove or land on the spool going past it (the seal lip) when I moved the spool back-and-forth. However, I did move the spool rearward more than its normal travel, trying to make it easier to compress the big spring and get the detent plunger thread started, so am now hoping that DID disturb the front seal someway. If not, then the lip-seals are rapidly failing and I will have to change all to quads... ugh! After all this fussing, knowing now how everything is built, I think I might be able to change all the spool seals (to quads) without removing the engine, or much else in the rear area except the spool covers. I now know rear access is "good enough", and you can leave the detents assembled if you are careful in pulling out the spools. The front will be a bit more difficult, as the big hose from the reservoir will have to stay in place, can only be disconnected at the front and bent out of the way as much as possible. I say that hose has to stay in place because I see no way to get to the fitting at the reservoir except by removing the engine and fan shroud; or maybe loosening the reservoir and lifting it up, but I don't want to explore that new process! This poor beast has become like a race-car or helicopter, lots of oil loss and 10-20 hrs of maintenance/repair for every hour of use.
