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Hydraulic hose coupling leak..

Yamaha ยท 2014-05-20 18:35

Hey guys, I don't post to often on this forum cause I don't know much on heavyequipment..but I read alot and you guys have some very helpful tips. I recently bought an older backhoe and one of the power steering hose coupling hose is leaking, the guy that I bought it from had just changed it with a new one. When I put a big load in the loader and try to turn it pisses out but after that it just drips out. So I was wondering if there was some sort of product I should put to stop the leak, I've tought of teflon tape but could it go.in the system and screw something up and would it hold up?? Alright thanks guys for any help you can provide, it's greatly appreciated :thumbup:

Replies7
  1. #1mitch5042014-05-20 21:04

    There are a number of different types of fittings it could be. Some seal on the threads, like pipe threads, some seal on a tapered flare, like JIC, and some seal on an o-ring. If the o-ring is on the outside it's called "o-ring boss". There are many other types of fittings too, but these seem to be most common on older equipment. What kind of backhoe is it? Can you post a pic of the leak? Have you tried tightening the fitting?

  2. #2Yamaha2014-05-20 21:51

    My Backhoe is a 1976 Mf50A ,and yeah i've tried tightening them a bit but didn't seem to work. Unfortunatly I can't take a picture right know because it's at one of our hunting proprety and I only go on the weekend. But thanks for you help.. Ohh..and i'm pretty sure mine seal on the thread if that helps.

  3. #3willie592014-05-20 21:59

    I'm asking because I don't know, but wasn't ** a British build machine?

  4. #4Yamaha2014-05-20 22:03

    To be honnest I don't know either, like I said before I am no expert haha . All I know is that I bought it in Canada *** Kidding aside, I bought a old manual for it and it was printed in a American city, but I can't remember it..

  5. #5willie592014-05-20 22:18

    Yes, they built ** machines in USA, and many other countries as well, I'm just saying I think it's a British design, but that I'm not sure about. Again, I know nothing about ** machines, but I was just wondering about the hose connections. If it does have thread sealing fittings it would have to be tapered pipe thread. And if it is British, it's possible it may have BSPT fittings. If so, if the former owner replaced a hose with NPT threads, it will leak.

  6. #6Yamaha2014-05-20 22:22

    Yeah I will have to check that this weekend, thanks I didn't think of that

  7. #7Delmer2014-05-20 22:53

    The hoses should be flare and the fittings that go into the cylinders are O ring boss. So the hose to adapter shouldn't leak unless it's loose or cracked or wrong fitting or? If the tee or elbow that goes into the cylinder is leaking at the cylinder then the o ring is cracked because it was rotated when it was installed. But don't take my word for it, the flare fittings come apart easy, and the o ring boss style you hold the fitting stationary and loosen the NUT only until you see the o ring, then you can unscrew the fitting and check the o ring.