Thread chaser for hydraulic fittings?

jacks

Member
I am replacing the hydraulic hoses on a 1973 International 175C crawler loader. The original hoses have JIC female couplings with a shallow threaded nut which only has about 4 internal threads. The new gates fittings used by the local hydraulic shops use a deeper nut with about 7 or 8 internal threads. The new style hose fittings will not engage far enough on some of the male ends to contact the cone ring and tighten up. Some of the male end threads were left exposed by the shorter connectors on the original hoses, and they have some rust and paint build up. I believe if I could clean up the threads, the new style fittings would thread on far enough to tighten up. Does anyone know of a thread chaser or die that is meant to use with hydraulic fittings?
 
I don't know. But since they're straight threads, you might be able to find something. I can't remember if maybe they're the same as NF bolts of the same size? How about a thread file?
 
I was browsing the McMaster site and see that they have a good assortment of thread repair dies. I am planning to measure the fitti g size and threads per inch tomorrow and call McMaster and see if they can recommend a die.
 
I usually just take a small rotary wire brush on a die grinder and clean them real good. On the other part in the worst case I have had to grind off some of the female nut so it will tighten down to the end of the male end. Worked on many 175c and had a 707 Gates hose machine so have BTDT.
 
I had thought of grinding down the end of the coupling nut to shorten it. That will be my plan B if thread cleaning does not work. It is good to hear from someone who has dealt with this same problem. Thanks for the suggestions.
 
I don't know of anyone making thread chasers in sies specifically for hydraulic fittings.

That being said, if you can get the fitting out a wire wheel on a grinder would do a good job of getting debris out of the threads, but aren't going to straighten out messed up threads.

For that you'll need a thread chaser like one of the ones at the first link below. Style B would be your best choice.

For smaller fittings, those that you can't remove, or those without the clearance for the thread chasers mentioned above, try the second link and get a thread file.

Both links are to McMaster Carr, so they can be ordered, and to your door, in a couple of days.

Good luck.
Thread chasers

thread files
 
I would be going to a hydraulic shop that supply the right fittings rather than having to adapt anything,JIC (Joint Industry Council) is a standard fitting on loads of machines,it sounds like slobbering to me to try and bodge up hydraulics fittings,get the right fittings.
AJ
 
Thanks for the advice Wayne. I ordered a thread repair die from McMaster for inch and 1/16 and 12 TPI from McMaster. Some of the hoses are going on after cleaning up the male ends with a wire brush. Others are going to need the die run on. Looks like I will get these all worked out. The original style fittings were called an Hu fitting and that company is no longer in business.
 
Sounds to me like they sold you the wrong style fitting, the nut dimensions are standard not any reason they should be deeper unless they sold you a sae or a ors fitting, which even if you get them threaded on the sealing surfaces will not mate and leak alot
 
Mark, I took the old hoses to one of the largest hydraulics suppliers in our state, and they said that the 1970's fittings on the old hoses were called an HU fitting, and the company that manufactured them went out of business. The fittings are a #12 JIC 3/4" size, but the JIC standard only refers to the seat angle and type of threads. All JIC fittings are not required to be identical in construction, just certain specs. Anyway, wire brushing the male end threads with a brass rotary wire brush cleaned the rust and paint off of the back threads which had previously been exposed to weather, repainting, dust, rust etc with the original hoses. I was able to get 4 out of 5 hoses installed just by wire brushing the male end threads. I ordered a thread chaser die from McMaster (1 1/16th x 12 threads per inch). I need to chase the male end threads on the last location which should allow that hose to install with no trouble. All of the currently manufactured JIC female connectors that the suppliers showed me have a longer and beefier thread barrel compared to the 1970's version. I feel like, when done, the hoses and connections will be superior to the originals.
 
What Jacks was told is correct, there are differences in some old, and new fittings. I didn't, and really still don't, know all of the details beyond what I just read he was told.

That aside, I too have run into JIC fittings on older equipment that had a shorter nut, therefore less thread, than a brand new fitting.

In cases like that, I had to do exactly what Jacks had to do and clean out the last couple of threads for the new fittings to tighten correctly.
 
I received the thread chaser from McMaster today. I ran it all the way onto the two male fitting ends where the new hose would not thread on far enough. Backed the die off and cleaned up the threads, and the new hose couplings now tightened up all the way. Added some hy-trans fluid to the reservoir and all is good, no leaks. My advice to anyone that is replacing old hoses with the short threaded nuts is to clean up the exposed threads thoroughly with a brass wire brush. If that doesn't work you will need to buy or borrow the right sized thread chaser die. There are plenty of charts available online that will help you identify the JIC fitting number, along with the thread type and threads per inch. The worst thing you could do is to keep applying torque to try to force the new fitting onto rusty dirty threads that have been exposed to the weather for many years. Thanks to everyone for the help and advice.
 

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