Sealing threads in a hydraulic system

Randy-IA

Member
Howdy everyone, I replaced the remote valves on the 1755 and I had new new hoses made to go to the couplers, these hoses use an adapter bushing on the coupler end that I removed from the old hoses. Since these bushings are straight threads they will need some sealing done to them. The had teflon tape on them before I took them off, but I know that normal teflon pipe tape is not the correct tape for this. What I don't know is a brand name for the correct type of hydraulic and oil resistant tape to use as well as the paste that's theoretically supposed to applied over the tape. I have rolls of normal white teflon pipe tape for water and air systems but nothing for oil/hydraulic. I only need it for these four coupler fittings--- the 4 hoses to bushings and bushings to couplers.

Any suggestions?

Thanks!
 
I've seen recommendations to use tape first then a pipe sealant over that. Is this still good advice or is a liquid sealer such as this just as good?

Things have changed some in the last decade since I last worked on hydraulics. Back then we used regular teflon paste and called it good.
 
you sure they are straight thread? straight thread is ORB fitting and have an o ring and does not require any sealant.pipe thread is a taper thread. for those you can use the liquid teflon sealant. or the tape.
 
I think they are straight thread, of course they could also be NPTF, but I can't visually see any taper in the threads. Nevertheless, my highly accurized, microscopic seeing eyeballs aren't what they used to be. It's obvious the threads used in/on the old hoses before were tight well before all the threads were used up, so my question might have been premature. I know I had to really bare down on the wrenches on the bench top to get these things to move!

The hose end to bushing is normal hose end and bushing to coupler is just to go from 3/8" hose size to a 1/2" Pioneer push/pull fitting. This is the way it's called out in the parts book. I don't work with hydraulic fittings much anymore and my recollect is getting dimmer.

I have to go back into town tomorrow so I'll pick up a tube of that Loctite 545. Needed or not it shouldn't hurt.

Thanks for straightening me out!
 
Wish the edit feature worked, it's ridiculous to have to write a complete new post to add one sentence or two.

Anyway...I just wanted to say that the valve end is ORB. The coupler end is NPTF just as everyone knew except me. The sealant will be for the couplers and bushings. All is well in the never-never land of my brain...LOL!
 
Not a good idea to use teflon tape on any hydraulic components. It does bad things when the little pieces come off. Use a good sealer recommended for hydraulic systems.
 
After visiting three different color tractor dealers in town looking for one square gasket for the hydraulic filter canister and talking to the mechanics at each place I found out they all used just plain white plumbers tape. It used to be called teflon but nowadays it's called PTFE (or generically- Teflon tape) LOL!

But mechknit was right, bits of tape coming off is a bad thing in a hydraulic system.

Keep it back from the first couple of threads and it's good to go. The same way I used to do it at the construction company. I guess some things don't change all that much.
 
I guess I must live under a lot of misconceptions. I thought Teflon tape was to keep threads from rusting together in plumbing water lines, not as a sealer. Guess I was wrong. I've never used any kind of sealer whatsoever with hydraulic lines. Didn't seem necessary since I've never had one leak when it was NPT threads. As far as rusting, it never seemed likely to me either with high pressure oil behind them.
 
This is what you want unless your working on water lines
cvphoto49833.png

Permatex thread sealant
 
You are probably right about the NPT not needing any sealer or tape. The coatings they put on hydraulic lines seldom rusts very badly and I've never seen them be extremely resistant to coming apart. I did feel that the couplers on these hoses, even with obvious tape and dope on them came apart extremely hard! They were torqued well beyond what I would consider necessary. Regardless, I've always used tape myself. I just asked because there have been improvements in just about everything since I did this over a decade ago when working on hydraulics occasionally (on construction equipment when lines burst).

I haven't worked on any of my tractors hydraulic lines (even though I should have) for at least the last decade. If it still works, deal with it...hahaha! Bad ideology I guess. But 'dealing' at this point was getting to be a major PITA since the levers were pretty well stuck tight I found out. Had I done a little recon mission I might not have had to buy those other valves. I was under the impression the sticking was due to messed up set of valve guts. I was afraid the spools had scored the bore too. I'll be taking those apart soon to see if in fact they are bad.

So, the tractor is all together now and it works, no leaks. Valves move like a warm knife through soft butter, the detentes work as far as I can feel so far, at least on the one I tested. The other feels like they will work, it pressurizes both hose and pushes back on my hand as soon as they are, which is instantly.

I believe I have a problem with one cylinder hose nipple now. The cylinder only cycles one way, switch leads and it cycles the other way when pushing valve lever in the opposite direction. (the valve worked it in both directions of the valve lever, but the one hose prevented the opposite action from happening) It could be I didn't have a good solid grip on the one hose when I was pushing them together, I was dripping with sweat and my hands were greasy and that hose was messier than the other. The couplers felt locked but maybe they weren't on that one hose. (I put new o-rings in all four of the two-way couplings yesterday) But it stayed with the same hose as I moved them. I'm going to hot water wash them when the weather cools some. Get all that old built up hydraulic gunk off the back of the tractor. I haven't mounted the female two-way couplers back onto the tractor yet.

The cylinder nipples are old and they weep too much for my liking, they are the ball valve type, I'm just going to be swapping them for new ones of the same type for now since I have a couple of new ones on hand (today maybe?). If that doesn't fix it then the valve is likely bad (doesn't appear to be bad) and I'll have to remove it again. Of course it's the innermost valve....I haven't tested the outer valve yet, the flying critters chased me inside last evening.

Regardless, I'm not going to do much outside today, it's too hot for my fat self to be out there working in the sun for too long today. I'll run out and do some small stuff for short periods, test that other valve, maybe change those nipples. Easy work.

The heat beat me up yesterday and the day before, it chewed on my brain a little, and spit me out! Today we have warnings. Even higher temps in the 90's and the humidity stays about the same. I used to work 10 hour days in this weather, but age and weight gain has taken it's toll. I like the cold much more than the hot!
 
Ya, I hear you. The heat doesn't bother me as much as it used to when I was carrying a few more pounds, but yesterday was about too much for a little while there. I went and bought another combine. When we finally got it started, I wanted to take the grain head off and bring it home. Those Gleaners don't come off as easy as the Olivers and Whites do. LOL

By the time we got it off and on to the trailer, I was feeling pretty woozy for a minute there. It sure felt good riding with the AC on coming home, I'll tell you that much.
 
What kind of Gleaner did you get? A pair of qick tach hooks on the feeder house makes hook up and detaching a lot easier. I got a lot of seat time ...

and wrench time....on a Gleaner, be glad to help if you need it


Good luck with it

Ben
 
I got a K2. Those wedges have to be pushed in and turned. You have to lay under it and roll the chain around to get the connecting link out of it too. The left wedge pin is behind the chain and you have to squeeze behind the wheel to even see something that's all but impossible to get to. On the Oliver, there's a coupler that slides in a hex shaft and two latch levers that you push and lock and that's all there is to it.

When we thought we had everything unlatched on the Gleaner, the left wedge had slipped back in and was bent a little from backing up trying to get out of it. I'll get it figured out eventually, but it'll never be as simple as the Oliver, or even the old F and G where you just took the connecting link out of a chain and took two bolts out of those blocks that locked things together.
 
K2 is a good machine, and yes that left hand wedge can be bear for someone my size and age lol! Most I've seen, you just had to shove it in and lift it up into the slot the unlock it. The concave door tool works ok for that, but a long wooden handled hammer works better, you can get a bit more momentum to your shove and the wood doesn't slip off as easily as steel. If you keep the header fully raised, with the ram stop down, it s a bit more accessible...depending again on the drive wheel spacing.

Ben
 
We're heading down to get it this morning. I'll post some pictures of it on the combine forum when we get it home.
 
What kind of Gleaner did you get? A pair of qick tach hooks on the feeder house makes hook up and detaching a lot easier. I got a lot of seat time ...

and wrench time....on a Gleaner, be glad to help if you need it


Good luck with it

Ben
 

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