Hydraulic connection installation question

Superduper · Jun 17, 2007

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 · Jun 17, 2007

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 · Jun 17, 2007

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 · Jun 17, 2007

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 · Jun 17, 2007

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 · Jun 17, 2007

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 · Jun 17, 2007

BTDT said:
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 · Jun 18, 2007

BTDT said:
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 · Jun 18, 2007

MadDogDriver said:
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 · Jun 18, 2007

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.