So I have been working on a John Deere 510 Backhoe for a while. It is getting close to being able to work a full day without me finding a new leak. Recently, I rebuild two cylinders, the differential lock valve and changed a extra hoses and fittings. Well, the bottom of the loader valve had a leak, a fairly good one, like, out of nowhere, it just started pouring out around the bottom of the cap. So, I suspect an o-ring somewhere in the valve. I get down there and place the wrench around the hex and the top of the cap and... it is loose.. I tighten the cap and restart it. No leak. This is not what I am asking about. I believe somehow the cap worked its way loose and started to leak. So far, I have a half day on it and it is fine. So, here is why I am here. After repairing a number of lines and finding the loose cap, all is okay... until.. I notice a wet spot after I move and, uggggg, I get out to investigate. The bottom line feeding into the port plate on the backhoe control valve assembly is leaking. Like a nice steady flow. I figure, another o-ring gave out due to this old beast having full hydraulic pressure again so I call to see if my parts desk has the o-ring and they do, so I run over to get it. I get back and begin the rubix cube of disassemble to get to the fitting that is leaking (14 lines and fitting don't make it easy to get a 1 1/2 wrench in there). Well, when I get in far enough to even try removing the fitting that was leaking i notice, it was REALLY easy to loosen. And, the fitting above it was tough and the o-ring on it was almost identical to the new one. Same flex, same feel... What I am asking is this... would you continue the several more hours of fighting to get the fitting off and replacing the o-ring, or would you re-assemble for about 20 mins and give it a try after tightening the fitting you found a little loose? ( think this will do it) And when I say several hours, it mean it, I have to take off at least 4 other lines in this tight little space to get to the fitting (and be able to spin it out of the space it is in).
What keeps the fitting tight is the squeeze on the O-ring and the thrust tension between the valve and the hex on the fitting. After so many heat cycles and time the O-rings will flatten. You would be much better off buying a kit such as https://www.herculesus.com/product.php?productid=626297
You've asked the age old question. Fix it right, or take a chance. The answer will be between you and God. I've done it both ways. Sometimes you get lucky, sometimes you have to take it all back apart and fix it anyway. If I was in the situation, I would ask myself a few questions: How far in am I? Could I be working on something more productive? What are the chances the o-ring is still intact? And the kicker-How sick of this thing am I?? Good luck on your quest.
Thanks guys. I am heading over to the machine now and doing it right. I am sure I will be cussing part of the time since it is so hard to get in there and have clearance to fit the wrench on the fitting and turn it.
So no cussing was required. It was a nice morning to work so I took my time, replaced all the o-rings that needed to be replaced and the ones that were not leaking but were in the way. (bought a kit so I didn't have to go get individual sizes). Here is the photo, of course it was the bottom left o-ring that was leaking but in order to get to it, all six on the left needed to be removed just to gain clearance.
zmountain, Not to tell you how to spend your money but I'd be saving up time and money to replace a few of those hoses! Better to do it in the shop on a rainy day than out in the swamp with mud up to you know where and `gators swimming around!