Open center Closed center?

[hydroholic]

Well here's the "Oh Yeah". Got my ebayism valve a Prince MB11 series single spool. Received it as an Open Center but installed the included 'plug' to make it Closed Center into the 'C' port. Put 'T's' into the "IN" and "TANK" lines to run my new valve in parallel. Hooked up the whole business only to find one of my hoses is a tad short, Monday it's back to PRG to get an extension. Bottom line, my Grapples work as designed/advertised, pictures at 6:00, i.e. next week.

The Prince valve is an 8gpm 3500psi valve and my grapples open in LESS than a second and close the same way. Wow, I am a happy 'grabber'. :0)

Pictures are worth a thousand words so I'll cut it here and go into detail with the pics. BTW as you know I am a retired electronic tech and this stuff is really new to me but lots of fun and YOU too can get into the act with very little investment. That's another story and it there is interest I'll pass it along. Secret is buy used and ask a LOT of questions.

Oh, the grapple hooks and the whole assembly was a 'sort-of' copy of things I had around here and things I bought off ebayism. The cylinder came from some junked fork lifts at the scrap yard, some American some foreign. Trust me stay AMERICAN, the necessary assembly fittings for hoses and such are not necessarily cheaper but available. Here's a quick peak at what I have done, needs a little paint:
Tractor Valve

 

[J_J]

One of your pictures says something about an open center valve.

How are you using that valve with a closed center hyd system?

 

[hydroholic]

That is how my problem started. I 'tried' using "a valve" (not knowing what I was doing) to control an installed grapple on my bukt/ldr tractor. That valve turned out to be an 'Open Center' valve with metric fittings and did NOT work the way I intended when I installed it into my existing system in series with the feed line.

Story ends there. You guys "saved" the day by advising using a 'Closed Center' valve and connecting it in parallel. GREAT joy, it worked. (except for my too short hoses which are in replacement mode on Monday)

I will put pictures up of the operation. Trust me, this is only to show that it can be done when you ask questions, and have a little ingenuity and a LOT of help from others who have already been down that path.
Again I thank all of you for your patient help.

hydroholic
sandbar w/fl

 

[ghenges]

I understand how a open center valve works, but how does a closed center valve work? What would the aplication be?

Thanks Bob

One huge advantage of closed center is valve plumbing.
All the pump's output doesn't have to flow though every valve. Smaller valves can used for one example.

Secondly, simultaneous valve operation at full pressure up to the pump's capacity

John Deere's closed center system was roundly criticized by International Harvester and other manufacturers years ago, now CaseIH tractors are now closed center.

 

[Tx Jim]

One huge advantage of closed center is valve plumbing.
All the pump's output doesn't have to flow though every valve. Smaller valves can used for one example.

Secondly, simultaneous valve operation at full pressure up to the pump's capacity

John Deere's closed center system was roundly criticized by International Harvester and other manufacturers years ago, now CaseIH tractors are now closed center.

Yes JD sales rep's brainwashed those that attended sales meetings(me included) back in the 60's -80's about the vast advantages of closed-center hyd's & lower link draft sensing. Now look what type hyd's & draft sensing a lot of JD tractors have? Open center & upper link sensing

 

[Tx Jim]

I understand the principles of closed center systems and respectfully disagree.
More than likely you have an unrelated internal high pressure leak that is causing the heat problem. Intermittent use of an undersized single spool valve isn't going to cause that much heat. It could be a 2 GPM valve and when not in use it may as well be a pipe plug. The user isn't likely to send the cylinder lock-to-lock at full speed anyway. Feathering the spool reduces its capacity.

I agree with Rick in that I think for extreme heat you have an internal leak which could BTW be a blown sealing ring on a open to closed conversion plug.

 

[hydroholic]

Yes JD sales rep's brainwashed those that attended sales meetings(me included) back in the 60's -80's about the vast advantages of closed-center hyd's & lower link draft sensing. Now look what type hyd's & draft sensing a lot of JD tractors have? Open center & upper link sensing

??? Being a novice at this I fail to see your comparison. Are you being sarcastic or just chiding JD for offering another way to connect a valve up in a system? Seems there are obvious advantages/disadvantages to both, wouldn't you say?

Given the choice, I personally prefer the CLOSED CENTER type. Why? Mainly for it's simplicity and EASE of connecting into an existing system. Works for me

hydroholic
sandbar w/fl

 

[Tx Jim]

I think I was not being sarcastic but rather making a statement about my experience of attending JD sales meetings back in the day. Have you ever diagnosed hyd problems on many JD tractors with closed center hyd's? I have and it probably in the 100's since I worked for a JD dealer for over 21 years in and around the service dept. Some closed center internal leaks are very difficult to find. Are you aware on JD lower link sensing that the lower link is at the very bottom of the trans and a tiny seal is holding back 10-15 gallons of oil? I see you have a JD 401C. JD's utility tractors such as yours are the most difficult to diagnose hyd problems. IMHO open center is much simpler hyd system than closed center but opinions resemble navels as everybody got one. I wish you the remaider of a Happy Easter,Jim

 

[hydroholic]

OK, surely not the experience working on "100's" but on ONE for sure and I'm still learning. Remember I initially opened saying I was a retired ELECTRONIC Tech. NOT exactly the most glowing credentials to be an expert by any means BUT I know what works, "in this instance", and what does NOT. Putting an Open Center valve in series with the main bkt/ldr spool does NOT work. Period. Been there, done that, seen the video, and got the 'T' shirt to prove it.

I'm NOT here to ruffle anybody's feathers because I DO appreciate the help that ALL of you have provided in solving "my" tractor problem. Asking a tractor, specifically a JD401-C, to do things it was NOT originally delivered to do AND not covered in their Manuals, calls for a "little extra help" in solving. You guys came to the rescue. Hurrah's!

Your point, regarding the difficulty working on the JD401, is well taken. Yes, it is VERY expensive and difficult to deal with. One of the points in the JD tech manual (p 35-1 Section 50) talks about an "aux" valve but then just leaves you hanging. Hence, that's when my problems started. I would have rather just inserted another spool for the function I needed and my troubles would have ended there, but no, I tried to re-invent the world. Long story but I'm a happy camper now, again, thanks to you all.

hydroholic
sandbar w/fl

 

[Tx Jim]

hydroholic
I'm going to clarify my statement that you referred to as sarcastic/chiding. All JD 2 cyl's were OC hyd's. Then with the introduction of the JD new Generation tractors JD had all of the models CC hyd except the 2 step children 1010/2010 that stayed OC hyd's. Then along came the 820,830 & early 2040(3 cyl ngines) which were OC. To my knowledge up until about 1992 all othe JD tractors built for N. American sales were CC hyd's and JD stressed how good CC was because their competitors didn't offer CC. Yes CC hyd has some advantages but when a hyd problem arises it can cause major grief. But to state CC is easier to add a hyd valve to is only true if one uses the correct valve. I hope this helps to clarify my previous statement.Jim