B7100 Directional Control Valve / Pipe Thread question

[Blackjack]

The owners manual for the B7100HST mentions the Directional Control Valve (under the front of the seat) has a thread size PS1/2 and the plug on the front case cover (return line) should be PF1/2. (Attached page)
Are these American or British Standard Sizes? ,,,tapered? I've seen some photos on this forum with just plain old galvanized pipe T's going into these.

I'd like to get the proper quick disconnect hyd hoses made up to run an attachment.

The only other issue I'm having is that I don't think this (Directional Control valve has been moved (ever),....and when I attempted to move it just now, it won't budge. I'm curious if it's not supposed to move until after I take the plug out, and replace it with a hose fitting. ...or if I even attempt to move it with a little "persuasion".

The operator manual says to "move the control lever on the tractor backward, and turn the grip on the directional control valve 180 degrees. Has anyone out there ever turned this valve? How hard could it be?

Does that mean that the valve should only be turned only with the tractor running?
If someone has an idea of the purpose of that procedure with the lever....before moving the valve....please shout out. I was thinking it was just to relieve any pressure that may be on the system, but presently there are no implements attached to the arms.
Any ideas are appreciated.
JB

View attachment 4152

 

[Blackjack]

Thanks OTT,
That answers the question on the PS/PF Fittings.....

Still looking for some guidance on anyone that has turned that Directional Control Valve....do I need to pull it out and turn it (as in..does it have a detent of sorts)...or does it just rotate 180 degrees? Does it matter which way to turn it CW or CCW or will it spin 360 either direction....

Blackjack

 

[Stubbyie]

Blackjack, can you post back what you found about the PS/PF threads?

You posted that you had the answer from OTT that may have been the thumbnail in your original post but I can't read it--the picture of text.

Thanks in advance for reposting.

 

[Blackjack]

Hey Stubbyie,
To answer your question...I got closer to the answer.
If you recall...the manual stated they are a PS 1/2 and PF 1/2 .

The OTT post (at that time)...directed me to Eaton Aeroquip Fittings website, where the various standards for ordering can be found.

http://aeroquip.cc/aeroquiphydraulicfittings.aspx

on that web page, the second paragraph has a link to pages 58-133 When you select that, you get a pdf download of their catalog that tells you a fitting index, fitting charts and how to order. It had all the abbreviations...and it had the "PF and PS" listed there.

PF = Female Pipe Swivel
PS = Pipe Swivel

(Trust me...I felt pretty stupid after finding that...but heck, I don't deal with hydraulic fittings...at all...so....now I know)

SO...I'm thinking that its a 1/2 inch Female Pipe Swivel and a 1/2 inch Pipe swivel. Nothing earth shattering.

Just the same, what I' was going to do..is just unscrew the darned plug, and unscrew the cap (to the tank)....plug the holes with a rag for an hour, and run down to a local shop that makes hydraulic fittings for bobcats....and have them verify the darned threads.

Then....I spoke with the local Kubota dealership...real nice service agent ....said not to rotate that Directional Control Valve unless I actually had an attachment hooked up, and a means for the pressure to flow through the attachment and back to the reservoir. He said since it is currently plugged, if I were to rotate that valve to the plugged position, the pump would be trying to route the pressure side somewhere....and being plugged it would probably damage the pump (since there was no-where for the fluid to go)....or seals. So I'm not touching that valve.

He also echoed what I've seen posted in the archives here, about the B7100 pump not putting out too much flow ( around 3- 3.5gpm) and that's only with it revved up pretty high (best case). That I'd probably be disappointed hooking a log splitter up to it, as I'd have to keep the tractor turning some high revolutions during the whole wood splitting evolution. Similar to the B7100 owners with a bucket having to lift a heavy load...they need to rev it up pretty good...only in this case, you'd have to power up for the duration.

I'm a little disappointed....but I'm learning to accept the fact, that it probably would be better to just go with a dedicated log splitter.

So that's about what I found. Maybe it will help someone else.
Blackjack

 

[Stubbyie]

Very helpful and a good reference link.

Thanks for posting the info.

I don't know your machine in the least but I've had three and currently have two Kubotas and have yet to see any kind of the several common and some not so common "pipe threads" on any of their hydraulic fittings.

If you learn different or others reading know better please advise.

I wonder if your nomenclature means ""swivel "hose" thread"" or something?

As best I remember from the earliest (and just swapped FEL hoses on latest) all the fittings were the JIC / SAE 37-degree "flare but not plumbing" type hydraulic fitting.

I'm going to study your link some more and also look at my Dixon catalog (not much trade with AeroQuip other than old air line fittings) and see what I can learn.

I appreciate your posting back. Never too old to learn. Now I can quit for the day.

 

[davidbham]

I am also trying to tap the hydraulics on my B7100HST to add a hydraulic top link. The manual says to "Remove the plug from the front case cover, and connect the return hose to the cover."

In the attached picture, do I have the correct item circled (is that "the plug from the front case cover')?

Thanks for any help - I'm new at this.

David

 

[Blackjack]

David,
I don't know. I never did tie in to the hyd system on my B7100 HST, as my Kubota rep told me I would be very unhappy with the @3gpm flow rate of the pump (and that's if it was new...he said it would be something less than that now. So I'm waiting for Santa to bring me a PTO driven Hyd pump next year.

Had I gone ahead and tied in, my plan for the return line was to tie back in to the fill spout hole....which in your picture, looks to be just to the left of the light blue filter. My cover does not cover that up, when all buttoned up...but you may have a slightly different mod than me. Since you have the cover off, can you physically view the reservoir in relation to where the hole you have circled ties in?....
I hope someone with more certitude on this can answer you, but I would GUESS that if that hole you have circled in your picture, is a tap that goes in to where the fill hole is for the hydraulics, I think you are spot on.
Blackjack

 

[steve]

Blackjack
If you are only looking for a one way piston tnen you only have to tap in at the valve. I have a top link that pulls in hydrolicly and extends by gravity on my wood box. Check out the photos.
Steve

 

[hodge]

Have you looked into a pto-driven pump, with a higher gpm?

 

[davidbham]

Steve,
I guess my primary use for the hydro toplink will be to adjust the tilt of the bush hog as the slope changes.

Would I have to throttle down to lower the cylinder with the single hose set up you have?

David

 

[steve]

David
You won't have to throtle down but you can only move the top link or lift the 3pt arms at a time. When the mower is lowered then switch over to the top link and mow away.
Steve

 

[Bellinghamster]

Pardon if you already know this: The valve in front of the seat is really more a diverter valve than "directional control". It sends flow to either the 3pt lift cylinder or the (plugged) port. Flow is controlled on/off with the 3pt control lever beside the seat regardless what position the diverter valve is in. Flow only goes one way (out the port), so you need an external open center spool valve if you want to power a bi-directional cylinder or motor.

My diverter valve was stuck really solid (previous owner never used it, let the tranny fill with water). I soaked it with Liquid Wrench for a few days, gave it a few taps with a hammper then crossed my fingers and started twisting it with some pliers. It moved just the tiniest bit, but each twist loosened it up more. Now it turns freely 90 degrees. (I had the same problem with the differential lock)

If you accidentally leave or move the diverter valve to the wrong position with the port plugged then move the 3pt control lever, the pressure relieve valve will squeal, but (should) prevent damage to the pump or anything else.

 

[davidbham]

Steve,

Tell me about the cylinder you used and how you plumbed it. I see both ports of the cylinder seem to be connected to the same line. Is there any directional flow control on either of the ports?

 

[davidbham]

I found this hydraulic top link at http://www.agrisupply.com

item # 67464 HYDRAULIC TOP LINK CATEGORY 1, 2" X8" STROKE
This one has a tang on the base end. On my B7100, the top link is mounted between the bases of the ROPS, and needed the extension.

I'll run it from the directional control valve and post pictures when I get it installed.

 

[davidbham]

Forgot to put the pics up, here they are:

 

[Whit]

Forgot to put the pics up, here they are:

How did you plumb this? Is the top link port closest to the back of the tractor just capped off? and when you have the diverter valve rotated to aux and lower the 3 point lever it just diverts the fluid back to the tank allowing the top link to extend under gravity?

 

[TheOldHokie]

How did you plumb this? Is the top link port closest to the back of the tractor just capped off? and when you have the diverter valve rotated to aux and lower the 3 point lever it just diverts the fluid back to the tank allowing the top link to extend under gravity?

Pardon if you already know this: The valve in front of the seat is really more a diverter valve than "directional control". It sends flow to either the 3pt lift cylinder or the (plugged) port. Flow is controlled on/off with the 3pt control lever beside the seat regardless what position the diverter valve is in. Flow only goes one way (out the port), so you need an external open center spool valve if you want to power a bi-directional cylinder or motor.

Bellinghamster explained the operation of the circuit. What are you trying to do?

Dan