Need help ordering new hydraulic couplings

seapea · May 9, 2023

I went to a local hydraulics store and was able to get the exact same couplers. They seem to be working well with my existing remotes. I was also able to get the 1/2" to 1/4" adapters. They aren't working so well. The leak badly on the 1/2" side where they connect to the hose. The 1/4" side that connects to the coupler is fine. I've tightened it down a lot and am afraid to go any tighter. Do I need to use tape or dope? The one thread I read on that topic just left me more confused.

The adapter is Parker part 0201-8-4. You can find it and its specs on the following catalog page:

https://www.parker.com/parkerimages/tfd/cat/pdffiles/G-Pipe-Port/fg.pdf

It says it is 1/2-14 NPTF, which is what my hose also claims to be, so I assume it is the right part. Any suggestions on how to resolve the leak?

seapea · May 10, 2023

I did a bit more research. From what I've read, NPTF is designed to not need any type of sealant, whereas NPT does need a sealant (mine is NPTF). Also, reuse of NPTF connectors is not recommended due to the deformation that happens during tightening, but if reused, then a sealant is recommended.

I'm a bit unsure how to proceed. It seems I have the right parts as they are both NPTF. Is my leak due to under-tightening or over-tightening? My guess would be the latter, so maybe the only hope at this point is to redo the connection with teflon tape.

workinonit · May 10, 2023

Talk to Kenny at Boltonhooks.com

seapea · May 10, 2023

For the most part I think I have the leaking resolved. I redid the fittings using teflon tape. Initially results were pretty good, but there was a slow leak with one of the fittings, maybe a drip every 5 seconds. Still, a vast improvement over the constant flow I was seeing before. I then tightened it up a bit, and it got a lot worse. So I redid it again, this time using a bit more tape (maybe 5-6 wraps instead of 3-4), and this time didn't tighten it as much. That seems to have worked really well. There might be a very slow leak, like a drip ever few minutes. I'll keep an eye on it. If it becomes problematic in the future, I might just have the hoses redone with 1/4 fittings so I don't need the adapter. Fortunately this leaking will only be an issue for the week or so a year I'll have my flail mower out, since that's the only time these hydraulic hoses will be attached.

ericm979 · May 10, 2023

Unless you're careful applying it, small bits of tape can end up in the hydraulic system.

I have had good results with LocTite 545, which is made for hydraulic NPT fasteners. Clean the threads well and let it cure for a day before using it.