? about banjo hydraulic fittings, JD790

[tomrscott]

I found a real good online catalog with a lot of application data about all types of hydraulic fittings:

http://hydraulics.eaton.com/products/pdfs/W-HYOV-MC001-E_application_data.pdf

It's the Weatherhead company, recently acquired by Eaton. They seem to be a bit supplier of this stuff.

Anyway, I was looking for a reference to banjo fittings. But with all the stuff this place has, they didn't have anything that helped. The SCV on my JD790 uses those at all the ports. I am not finding these connectors in any of the usual places.

I found a British company that had British threaded banjos that then convert to a tubing coupling.

http://www.indanc.com/steel-compression-fittings-06.htm

I noticed that they say the male thread that compresses the banjo part, is available as a BSPP or metric thread.

But that begs the question, what is the thread on the JD banjo going to be? Is it going to be metric? Or does JD/Yanmar use American standards for those things?

Is it possible that some other male threaded fitting, not necessarily a banjo can be screwed into the port that they've connected a banjo to? The tubing that is connected with the JD banjo appears to be 3/8" with 0.485" OD. The hex head on top of the banjo is approximately 1.07", didn't have a socket set handy to try and see what fit. The banjo ring that is clamped by the "bolt" is about 0.7" thick. I don't really want to take these things apart until I am ready to re-do it. I suspect they could be real tight, and the quarters are cramped. I need to tap into the hydraulics PB at the FEL SCV and then return to the rockshaft P port.

I am just wondering if the port this banjo is screwed into is actually a 1/2" NPTF or something that I can put a standard 90 ell with a compression coupling on the other side?

Maybe I don't need to find a banjo?

Anybody know what these threads are, or a source for the correct banjo fittings? I'd like to run tubing for the power lines to the TNT, but may settle for hoses, but I have to figure out how to connect to those.

Thanks!

 

[MadReferee]

If the fittings are tapped 3/8 BSPP then just get a BSPP to 3/8 NPTF or JIC adapter sleeve and use standard readily available fittings from there. That's what I did on the TCC tilt cylinder I have (I adapted to JIC).

BTW, for those interested, the TCC and CCM cylinders with the check valves are threaded 3/8 BSPP. This is according to Jim McCuan of Integration Engineering.

It's interesting to note also that a 3/8 NPTF male fitting will screw partially (almost all the way) into the BSPP female and depending on tolerances will most likely work.

 

[texbaylea]

Mad

I am glad to know the thread on the CCM top link. I just got mine and was looking for a swivel adapter to put at the check valve to avoid twists in the hoses. I intend to use 90* elbows at the QD ends so that the hoses are in a single plane. I had found 3/8 NPT to 3/8 NPS female adapters but they would only thread into the ports on the check valve about 2-3 turns. I decided at that point to stop and think about it before I put it together.

Thanks
Vernon

 

[tomrscott]

If you go read the application data in that Weatherhead pdf, you will find that they say the BSxx and NPxx threads are very similar, but tooth angle is not the same and they should not be interchanged.

MAD,
I think I confused you with my question. I don't know what the female thread is in the JD 790 systems that have banjo fittings screwd into them. Particularly the power beyond port on the FEL SCV and the rockshaft port it is plumbed into. What I am trying to figure out is what I can use to tap into those ports, short of buying a replacement of the line JD uses between those ports, cutting it apart, and adapting it with a flare coupling or someting.

The BSPP banjos adapters I found would be great if that's what the JD female used. If I am going to get an adapter from the BSPP thread to the JD, I still have to solve the original problem which is what does the JD require? Is it an NPTF, or an SAE, or some metric, or what? Once I know that, I don't need the BSPP banjos.

Banjo fittings seem like a good mechanical design, you get a lot of compression in a nearly flush right angle. I think the bell of the banjo takes some tension in its curved sides. without a special fitting like that British thing, it requires a custom welded tubing end. It may be lowest cost and great performance in production volume, but a nuisance to make in the field.

Again, the key to my question is: what is the female thread that banjo is screwed into? Is it some thread standard that I can put some other sort of fitting into, or is it actually a unique thread that has to have a banjo fitting (not likely I think)? In the latter case, does anyone know where I could get something like straight tubing with say a banjo ring on one end and flare on the other, something I can make up the line I need?

 

[MadReferee]

Well, I guess you will have to just take one out and measure. A JD workshop manual or even a parts manual might give a fitting size. You could also try asking in the JD Owning/Operating forum where someone who doesn't visit here might know. It's probably either 3/8" NPTF or SAE 6 or 8. I would be surprised if it is something else.

BSPP threads are usually found on stuff from Europe (like the cylinders I mentioned).

As I pointed out BSPP and NFT threads should not be interchanged BUT if you can't find adapters, they will go together (with a little bit of force) and 9 times out of 10 will hold just fine. Just don't take them apart.

 

[tomrscott]

I've got pretty good consensus from a few people that it is probably not a NPTF. You wouldn't want to use a tapered thread on a banjo because the taper might bottom out before your copper crush washers are the right compression. It pretty well has to be a parallel thread of some kind.

 

[RobS]

Tom, I can check my parts box tonight. Should be an extra banjo bolt from the power beyond kit in there. Stay tuned /forums/images/graemlins/smile.gif

 

[tomrscott]

I looked again yesterday at that banjo bolt head trying to figure out what wrench size it is. It is in a slightly awkward location, so it is a bit hard to get a calipers on it. I decided that it is either 1 1/16" or 27mm which are almost identical.

But 1 1/16" seemed like it would be pretty uncommon, so I was going to say was probably 27mm. Then I noticed there were some markings on the bolt head, so I did a pencil rubbing of them and found they say "3/4" in big raised numbers!

So is it likely that it is a 3/4" SAE?

I guess what I should do is go down to the JD store and see if I can buy one of those banjo bolts. Then I'll have one to measure and can be sure to get the right thing.

I am going to go study the hydraulic fittings "applications" section of the Eaton Catalog pages I printed out. I think I am getting close to a solution here.

 

[MadReferee]

</font><font color="blue" class="small">( Then I noticed there were some markings on the bolt head, so I did a pencil rubbing of them and found they say "3/4" in big raised numbers! So is it likely that it is a 3/4" SAE?)</font>

3/4" x 16 threads for hydraulics are referred to as SAE 8. If that is what you really have there are plenty of readily available adapters to go from SAE 8 to just about anything.

SAE 8 threads are commonly used for work ports. Prince SV valves use this size as do many others.

 

[tomrscott]

Mad,

Yeah, I think that is what I am going to find, 3/4x16 SAE 8.

So I'm looking at the Eaton catalog at a right angle fitting that has a straight thread O-ring seal (with a nut so you can adjust the rotation), and a flareless tubing connection they call a "7000 series Ermeto".

The only trouble with that is, it looks like the one that has a 3/4x16 straight thread O-ring for the port will have a 3/4" tubing connection. But they also have a reducer peice that is has a stub of 3/4" tube attached to a coupling for 1/2" or 3/8" tube.

The tubing coming out of the banjo is a peculiar size. At first I thought it was 1/2" OD, but it is only 0.475", which happens to be real close to 12mm, and if I account for the paint on it, it could be exactly 12mm. I wonder if that is a standard size in Japan? Since I am adding three feet or so round trip to put a new SCV in the circuit, I should probably use 1/2" which is just a little larger.