Hydraulic connection installation question

[Superduper]

Hi all,

Finally took the plunge and purchased new diverter valve kit to install in JD3120 tractor. The kit was much more extensive than I expected and while certainly pricey, all I know is that I wouldn't want to fabricate everything that the kit comes with.

In any event, I figure there are at least 30+ hydraulic connections. I'm going to try to do the install next week. This is my first attempt at hydraulic line installation and I would appreciate any tips and hints on installing the lines and connections with a focus on minimizing potential problems and leaks during the installation. Should I use teflon tape on the threads or are they normally installed dry? Should I install them snug and then go over and retighten if they leak or should I just crank down on them to begin with? Since there is no way to get a socket on them, I am afraid of overtightening them as I am not aware of any torque wrench for open-end or flare-nut wrenches. If hydraulic fittings are anywhere near as difficult to get leak free as plumbing-compression fittings on water pipes, I am not looking forward to this. Thanks in advance.

~Super.

 

[BTDT]

Folks say no teflon tape. There is a pipe dope suitable for hydraulics that you can use on the fittings with pipe threads. The other fittings (JIC, etc), I would just snug up and see if it leaks, then like you said, tighten from there till it stops. If you go overboard tightening them to begin with, then if it leaks, you have problems. I would try to keep flow/installation as straight as possible, to minimize hoses being in a situation where they could kink. Are any of your connections going to be QD's?

 

[MadDogDriver]

There is a NO TEFLON camp for hyd fittings.

But for the rest of us, including myself, many have had no problems using teflon. Just make sure you keep it on the threads and out of the inner diameter of your male fitting.

Getting dope inside the fitting will yield problems just as little pieces of teflon will. I don't recommend dry fittings, use hyd suitable dope or teflon (if so inclined).

 

[BTDT]

I don't recommend dry fittings, use hyd suitable dope or teflon (if so inclined).

You aren't suggesting using tape/dope on flared fittings are you, they are usually tightened up dry, or that's the way I've always done it. Just tape/dope pipe thread fittings.

 

[Chris2520]

He is not talking about the compression fittings. he is talking about the pipe fittings....
Nothing go's on the commpression fittings...
only on the pipe fittings.

 

[kennyd]

I am definitely in the "No Teflon Tape" camp. Use a good quality pipe dope that is rated for use with hydraulics. I use it on ALL fittings, even the JIC style. It helps lubricate the threads and will keep corrosion at bay also.

It's definitely not cheap...but it's a PITA to have to redo fittings!

 

[MadDogDriver]

You aren't suggesting using tape/dope on flared fittings are you, they are usually tightened up dry, or that's the way I've always done it. Just tape/dope pipe thread fittings.

Like Chris said and I should've clarified......pipe thread fittings for the teflon/dope, not flared compression fittings.

 

[Superduper]

Folks say no teflon tape. There is a pipe dope suitable for hydraulics that you can use on the fittings with pipe threads. The other fittings (JIC, etc), I would just snug up and see if it leaks, then like you said, tighten from there till it stops. If you go overboard tightening them to begin with, then if it leaks, you have problems. I would try to keep flow/installation as straight as possible, to minimize hoses being in a situation where they could kink. Are any of your connections going to be QD's?

Yes, the diverter kit removes the original connections to the MM hydraulics and puts the diverter valve in it's place, therefore, there are 4 QD's at the MM location and places 4 more at the rear. With everything apart, I will also be installing the power beyond kit at the same time so include 2 more QD's for a total of 10. As far as routing the lines, the kit is a JD kit so it is already designed including all of the routing. The kit uses all hard lines which are already pre-bent, which I like but there are 2 flexible lines which goes from one side of the tractor to the other to (the MM PTO diverter) and the instructions are not clear how to route that other than to route it over.

 

[Superduper]

There is a NO TEFLON camp for hyd fittings.

I don't recommend dry fittings, use hyd suitable dope or teflon (if so inclined).

Would this be the dope used on normal plumbing installations, such as PTFE?

 

[MadDogDriver]

What's recommended is a product that states that it's suitable for hydraulic fittings. What you're obviously trying to do is prevent anything from possibly getting into the fluid that would contaminate it.

There are several products available that I'm aware of. PERMA-LOK pipe sealant LH-050 is one, DuPont's Megaloc, Permatex and Loctite are others that I know of. Loctite has a range of hydraulic sealant products, one of which is Loctite 542. Loctite states that 542 contains no particles which can contaminate the hyd fluid, valves and orifices. It takes several hours for the sealant to fully cure, but this can be reduced to about 30 minutes with an accelerator like Loctite 7649 Activator. I'm sure there are other product available that will do the job also.

Make sure the fittings are clean of film oil and dirt before applying the sealant. Hot water and detergent works if you don't want to buy any of the commercial products available that remove all contaminants.

 

[Superduper]

Thanks everyone for all the great advice. Looks like I'm going to get delayed by another week or so, as according to the wife, I need to do the earning money thing first . As you can see, our priorities don't always coincide. In the meantime, I'll search for some hydraulic sealant. Now, I just need to figure out how I'm going to torque these things to 37 lb.ft. I figure the only way (unless there is a tool out there that I'm unaware of) is to tighten the fittings with a crowsfoot adapter via 3/8" torque wrench. Since the crowsfoot adds length to the wrench, there will probably need to be some adjustment down from the 37lb/ft specification. Also, large 24mm and 1-3/8" crowsfoot flares are mighty rare and expensive so I'll probably need to use standard open-end crowsfoot but I figure that 37lb/ft should be OK with such large fittings. Or what the heck, should I just "guestimate" the torque specification?

~Super.

 

[Farmerford]

Super:

I am not sure where 37 ft# came from, but there are standard tables for pipe, JIC fittings, and flareless that specify tightness in terms of turns from hand/finger tight for pipe and flats (on the hex) from hand/finger tight for JIC and flareless. Just Google "fittings tight turns flats" or something like that and look. These specs are for the first tightening only. If the fitting does not leak, mark the position of the nut and fitting with a felt tip pen and then return to the same positon if you disassemble the fitting. If it leaks, tighten it just a little at the time until it stops, then mark it.

O-ring boss fittings usually specify torque (though I think I recall one that had flats from finger tight), but the secret with o-ring boss fittings is 1. to back the adjusting nut off all the way and then tighten the fitting until the o-ring is pressed almost all the way into the boss and the washer is pressed up against the threads for the adjusting nut, then 2. tighten the adjusting nut until the washer is against the boss, at which time metal is striking metal and the o-ring is properly compressed into the boss by the washer, smooth shank of the fitting, and the boss itself, and then 3. tighten the adjusting nut firmly (only a flat or so) just to keep it from loosening.

 

[Superduper]

Super:

I am not sure where 37 ft# came from, but there are standard tables for pipe, JIC fittings, and flareless that specify tightness in terms of turns from hand/finger tight for pipe and flats (on the hex) from hand/finger tight for JIC and flareless. Just Google "fittings tight turns flats" or something like that and look. These specs are for the first tightening only. If the fitting does not leak, mark the position of the nut and fitting with a felt tip pen and then return to the same positon if you disassemble the fitting. If it leaks, tighten it just a little at the time until it stops, then mark it.

O-ring boss fittings usually specify torque (though I think I recall one that had flats from finger tight), but the secret with o-ring boss fittings is 1. to back the adjusting nut off all the way and then tighten the fitting until the o-ring is pressed almost all the way into the boss and the washer is pressed up against the threads for the adjusting nut, then 2. tighten the adjusting nut until the washer is against the boss, at which time metal is striking metal and the o-ring is properly compressed into the boss by the washer, smooth shank of the fitting, and the boss itself, and then 3. tighten the adjusting nut firmly (only a flat or so) just to keep it from loosening.

Farmerford, the 37 ft# specification comes from the installation manual. A bunch of adapters are included as well. The kit comes with a parts bag that weights like 10 lbs. full of fittings, adapters, QC couplers, etc. I did not open the bag yet because if I do, something will get lost somewhere but it seems that O-rings are used on many of the fittings.

Unfortunately, you sort of lost me with your o-ring boss description but perhaps when I dive into it, it will become clear what you're trying to say. At this time, I can't picture it nor do I know what is the adjusting nut because all I see are metal tubes with a rotatable sleeve (hat?) that presumably tightens the tube onto the fitting.

I did notice that the installation manual makes no mention of using thread sealant, teflon tape, or pipe dope anywhere. The manual also includes directions such as install tubes as shown, but doesn't mention any further details. Noticeably missing is any information on how to install the Quick Disconect couplers.

In all likelihood, when I jump in, everything will become clear.

 

[kemartin3]

I can't lay my hands on the sheet of paper at the moment, but as memory serves, as long as you have the crow's foot turned 90 degrees to the line of the shaft of the wrench, then you don't have to adjust the torque setting. You haven't changed the effective length of the wrench.

If you have the crow's foot aligned with the shaft of the wrench, the manual for my Sear's wrench says

1. Measure the "lever length" of the wrench (L). In my case, from about the middle of the operator's rubber handle to the center of the square shaft where you normally snap on the socket.
2. Measure the effective length of the extention (E). That is, from the center of the square attachment hole to the center of where the nut will be.
3. Use the formula TW = TE * (L/(L+E))

where TW is the torque wrench setting and TE is the torque you want to apply to the nut.

Hope this helps,
Kevin

 

[Superduper]

1. Measure the "lever length" of the wrench (L). In my case, from about the middle of the operator's rubber handle to the center of the square shaft where you normally snap on the socket.
2. Measure the effective length of the extention (E). That is, from the center of the square attachment hole to the center of where the nut will be.
3. Use the formula TW = TE * (L/(L+E))

where TW is the torque wrench setting and TE is the torque you want to apply to the nut.

Hope this helps,
Kevin

Thanks Kevin. It will come in handy.