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Case 648BH
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Discussion Starter · #1 ·
All,

There are a handful of npt connections on my 648bh that I'm assuming are standard. a previous owner had used tape to make a better seal. however I've used loctite 545 in hydraulic systems that included servo valves in a professional setting. Its a sealant so helps leaks but also acts as a thread locker and it does not contaminate oil or foul small orifices if it is introduced to the fluid. permatex makes a similar product. it could also be used to lock jic fittings if that was desired.



tks
 

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'68 - Case 155, '73 - 646a
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Yep. Curious where you found 'npt' Ala Pipe thread on a STOCK 648. I cannot think of anything other than maybe the filter in the return line that is NPT? Case LOVES to use Jic connectors, Page # 4 in https://www.discounthydraulichose.com/mm5/thread_guide.pdf and SAE Straight Thread O-Ring (ORB) Page #6 in same book, for just about everything.

Looking at the parts book for a 648BH there appear to be couplers in the lines to the back hoe that might be NPT. But anything on the loader valve or the TCV is SAE to JIC..

and 545 is a great choice for NPT threads. Jic and SAE should seal and hold with out any paste, or locking compound and Teflon tape is an absolute NO NO in a hydraulic system.
 

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I never ran in to NPT on my 646's D-100. Just JIC, and ORB. I don't recall what I had right at the cylinders though, so that's a possibility.
 

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Ingersoll Dealer
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While JIC and SAE O-Ring Boss are prominent through out the system, lift cylinders (loader, mid, and 3 point) and PTO / Backhoe circuits also utilize pipe thread connections.

Thanks for posting the product alternative as tape can be problematic if no cautiously applied.


Brian
 

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Case 648BH
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Discussion Starter · #5 ·
Here’s an example from one of the bucket lift cylinders that I’m rebuilding.
121382

The fitting threads into the standoff on the cylinder and adapts from npt to jic. It had tape on it but I will be switching to 545.
 

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I hate NPT in hydraulic systems. Much prefer O-ring and Jic, but I've always used a product from highside chemicals called leak lock on NPT fittings . It's an amazing sealer that is good up to 10,000 psi. Also works good on steam lines. You can read all the stuff it's good for on the website. I've used tape before, anti seize (helps lubricate thread to get a tighter thread takeup) put them in dry. But I found leak lock to work the best. (haven't used that Loctite product though)

 

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Just used some of the Loctite this weekend on my log splitter. The suction hose attaches to the hydraulic tank with a 1"NPT/1" hose barb. That fitting was leaking. Come to find out it was plastic! The fitting wouldn't tighten up after 27 years. Grabbed a brass one from Menards, applied Loctite and reassembled. The fitting was cheap. The $80 worth of hydraulic oil sucked.

This splitter was a custom kit back in the day built by Northern Hydraulics in MN. I was very surprised there was a plastic fitting in there. Oh well it lasted that long. Split about a cord yesterday and didn't loose a drop.
 
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