Adding Multiple Hydraulic Control Valves to the tractor

[Furu]

I debated as to putting this in Projects or Hydraulics and decided to put this here.


Part 1
I had a need to add additional SCV's to a JD 4720. I received some good ideas and recommendations and want to thank Kennyd specifically for the hydraulic thoughts and mjncad for the ideas on hard lines and brazing fittings.

I posted this on another forum but thought that I would document this here so that TBN members could get ideas and modify for their use.

I have a 96 inch heavy duty rear blade that has three-way adjustment with three-way hydraulics that is a bear to use properly without three independent SCV's. Thus my aux system design.

The next set of postings will attempt to logically document the process that I went through in my design and fabrication of what I came up with to meet my requirements. If too much information, I am sorry but I am trying to include detail for anyone that wants to learn from my mistakes.

The original requirement was for three additional SCV's (spool valves) for use. Effectively a 4th, 5th, and 6th SCV. I did not plan on using my JD 3rd SCV as it is reserved for front end 3rd function use. The standard JD 4th and 5th SCV uses a diverter valve to switch the FEL controls and valves to the rear end. More money than I wanted to give JD dealer and just did not seem to fill the requirement. For some folks it maybe the correct solution.

I decided to go with a 14gpm Wolverine WVS series 4 spool monoblock control valve so that I have a spare SCV for any future growth that might come up.
Item 9-7978 WVS41BBBB5C1
(Surplus Center - 4 SPOOL 14 GPM PRINCE WVS41BBBB5C1 DA VALVE)


SCV with FF fittings installed

I decided that I had to satellite the QD's for the hydraulics and with the real-estate available I chose to use hard lines to avoid the rat nest that 10 hoses would cause. I really wanted to use the JD mounting plate for the 4/5 SCV but there was not enough room to have 8 QD there, only the four that the JD kit used. I also wanted a bit more room between QD so that with gloves on I did not fight it as much.

Problem was to locate the SCV, the QD's and the hydraulic lines so that there would be no interference with the three point at any point of travel or with any implement that I was using. I decide to mount the SCV on the side of the ROPS and put the QD's in the middle, high enough up that lines to the implements would not be caught by the three point itself.


Mockup


Mockup

I decided to mount the SCV on a 0.375 in x 5 in x12.5 in steel plate U-bolted to the ROPS using the same type U-bolts that JD uses for the canopy. I decided against using 0.25 inch plate when I did the mockup. I mounted one plate on each side of the ROPS and then put 0.75 x 0.125 inch square tubing supported between them for the QD's mount. Originally I was going to weld the square tubing to the 0.375 in plate but decided to make the unit easier to assemble and if necessary disassemble by making it modular. As a result I attached the square tubing to 0.125 in plate which then was attached to the larger plate with the same U-bolts that mounted to the ROPS.


Mounting plate with 2 large holes to go over bolts on ROPS that mount the lights

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 2

For additional structural support I cut 0.75 in square holes in the 0.125 in plate so that it was supported not only by the weld but by the steel itself. Without a fancy machine shop I learned a lot of skills using hand tools only during this project. Making 0.75 in square holes were fun.


Cross members with thin plates for mounting

I had to recess the SCV mounting bolt heads in the 0.375 in plate because the bolt heads interfered with the ROPS structure on the back side. The fourth hole in the SCV was not tapped for a bolt so I tapped it and added a bolt for extra security. Of course it had to be a different size because the blank was too large to tap the same size thread. (Probably not necessary but did not like mounting the heavy SCV on three bolts only.)


SCV mounting holes with recess for bolt heads


Opposite side view


All structural components before welding


Closeup of cross members before welding


Close-up of crossmember TIG welded to thin plate bolted to mount plate for ROPS

Shield Arc volunteered to TIG weld the Square tubing to the thin plate which turned out VERY nice. Thank you to Shield Arc. I was going to arc weld it but he said how much nicer it would be and it is.


Size of work area around SCV

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 3
Since my flow rate through the PB is 12 GPM and the JD PB lines are 0.625 in (#10) I decided that the supply and return lines from the SCV would need to be 0.625 in as well. Since all the other lines on the existing SCV’s are 0.5 in (#8) I decided that I would use the same so that there would never be a flow restriction for anything I wanted to do. I could use an orifice on a hydraulic ram if I needed to slow down the rate. Originally I was not going to put a PB port on the four spool SCV but decided after some additional research that installing it would remove any backflow strain on the valves in the aux SCV that I was adding. On the mounting plate for the QD’s for the four valves I also put connection points to plug the PB hoses to. As a result I have hoses running from the PB supply to the aux hydraulic plate and PB return hose back from the plate and a hose from the bypass of the SCV to the JD sump. Everything else was hard lined. I did not want to permanently hook my PB to the aux system as I would have potential problems with my backhoe and a couple of other attachments. The aux plate is 12 gauge steel so that the QD’s and any torque applied would not bend/warp the plate.


Mounting plate during fabrication

After coming up with the basic design and starting to put it together it started to take shape.


Unit bolted together as if on tractor


QD installed on mounting plate


Backside of aux unit before hardlines

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 4

I was now ready to start to work on the hard lines for the plumbing. I address the tube bending issue in the next separate post. This will address the end couplings. Finding silver braze rings was a problem. The only Parker store that had them in stock was in Anchorage (really nice store with very helpful folks) My local hydraulic stores (PNW Washington) said they had not heard of anyone using them for 15 years and they did not stock them nor doubted if they could get them ordered. As mentioned earlier “mjncad” said he made his braze rings, so that was one option that I looked at, but I contacted one old timer that told me how in the early days before Parker came out with the braze ring idea that they brazed the fittings on just like you sweat a copper plumbing joint only with different flux, different filler and obviously a lot more heat (pre-braze ring style). It ended up that I did a combination of those two methods. I liked both and used the ring method with the 0.5in #8 tube and a combination of ring and “pre-braze ring style” on the 0.625 in #10 tube due to the larger diameter tubing. It was a skill that I acquired rapidly due to my O-A welding days but I did have a problem supplying a little more heat than necessary initially. Using the feathers of the flame for heating rather than the cone was what I found worked the best. The filler material was not cheap due to the percentage of silver required for this type of brazing but was worth it and much cheaper than paying someone to flare each tube. 20 flares would have broken the bank at the rate they wanted to charge and according to my neighbor who used to work in the industry they make mistakes and destroy the tube frequently. After fabricating each tube to have to replace it because of their mistake would have been bad. My average tube took 45-60 minutes to fabricate to fit the way I wanted. Lots of hand trimming the ends to get a correct fit was required as well as multiple bends. Parker documentation clearly dislikes straight hydraulic tubes for several reasons so I tried to avoid it as much as I could. I do have one #10 tube that has very minimal bends in it but there are some and there is play in the mount. The issue with straight tubing between fittings is that there is no play and thus the stress build up in the tubes and joints whether brazed or flared straight lines are not good.


My homemade braze ring inside a 0.5 in FF sleeve


A finished sleeve brazed on 0.5 in tubing


Another look at a brazed fitting flush with the FF fitting on the SCV without the nut

After brazing the tubes I had to ensure the inside of the tubes were adequately clean so I would not contaminate my hydraulic fluid reservoir in the tractor. I finally went with HCL acid flushing of the tube insides and then neutralized the acid and flushed the tubes with diesel for final cleaning. It amazed me how easy the access to concentrated HCL is available to the general public.

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 5

Bending the tubing was an issue. A normal tubing bender that you can find is designed for copper not steel hydraulic tubing. A good steel tubing bender is rather expensive $400+ for each size and I needed 0.5 in and 0.625 in benders. I found a 0.5 in bender than I thought would work that was advertised as being for hydraulic tubing for $29. I should have known. Cheap Chinese design, it broke on the second bend at the rivet that held it together. The company did replace it but it put me out of commission for nearly 3 weeks while I waited for the replacement. In hindsight I should have modified it and repaired it rather than returning it but I had to hope I had a lemon. The replacement lasted about 15 bends before it broke in the same place, the poorly designed rivet. The rivet was a stepped diameter 12 mm for part and 10.5 mm for part. I drilled out the handle to 12 mm and put a 12 mm bolt through and the unit worked like a champ from then on. The 0.625 in bender was a bit more of a problem. From an internet search I found the same manufacturer in China but they only sold them in very large batches, no single sales and no US importer seemed to carry them. I did find a 0.625 in bar bender at HF (advertised as a tube bender, NOT) that I thought might work but it collapsed the tube on most efforts. I finally used a combination of heat and parts from the disassembled HF unit to make the bends. I am happy with the final product but 0.625 in tube bending was my biggest problem.


Unit after rivet broke before repair


After two hardlines


Starting to take shape

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 6

After finishing the fabrication of parts I had to decide how to finish the final product. I decided to spray it with enamel with hardener to get the best durable finish I could. I did not want a high gloss but more of a matte finish. I primed the surfaces with two coats of primer after prepping the surfaces and then followed up with three to four coats of enamel depending upon which part I was spraying. Unfortunately my very tight tolerances did result in some paint loss on the thick plates during final assembly. If I was to repeat I would loosen the tolerances on the cross-members a little bit so the thin plates would not scrape the thick plates as I was installing them on the tractor.


Primed mounting plates


Ten hardline hydraulic tubes.
Note next to the bottom is the 0.625 in tube that has the least bend in it.


Crossmembers

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 7
The aux unit was designed with brazed fitting hardlines with ORFS fittings. I avoided any use of NPT fittings. The SCV and QD’s are all ORB. I used the existing JD PB return hydraulic hose to connect with the return port on the aux unit. I had Discount Hydraulic Hose make my hose to length for the PB supply to aux unit. It cost “parts plus $12” a far cry better than the local folks. Just do not expect rapid service as every order I placed took at least one week and one-time two weeks before they got it shipped. The ORFS fitting on one end of my ordered hose had a rather significant gouge that they said was acceptable but I polished it out as I thought it might contribute to a leak. I was overall very happy using them for parts. I purchased the SCV and one JIC hose from Surplus Center (Surplus Center - Hydraulics, Engines, Electrical and More) I originally was going to use the JIC hose to go from the SCV return to sump port because it was pre made, cheaper and did not have to be an exact length. I eventually put an inline filter (same as the JD inline on the PB return circuit) that I will leave on for a while. As a result that hose is a bit longer than I would like because of the extra length due to the filter and associated fittings and may shorten it to an 18 in section.
My final product pictures follow.


Rear of unit


Looking rearward from the left side.


Looking rearward from the right side

I have the forward plate off in this picture so the inside tubes can be seen. This plate is slightly thinner as it is 16 gauge with an extinguisher attached to it on the tractor right side, left as you look at the above picture.


Aux unit plugged into itself when PB is to be used for something else

In theory with the PB port on the aux SCV I could use the aux output as my PB for the BH or log splitter but I will not do so. When not in use the JD PB will be isolated from the aux unit to reduce any friction heating that may occur. I did not hardline to the JD PB but used hoses for just the reason I list above to keep it isolated when not in use.

View of location of SCV from operator seat

 

[Red Horse]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Wow! A beautiful job-way beyond my skillsets-what do you figure your total cost was?

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 8
I now have about 25 hours of work with my LP 4096 rear blade using the three way hydraulic control that I built. I am VERY pleased with the result.
Two things that I would do different.
I designed the QD mounting plate for symmetry and should have looked at doing it more perfectly lined up with the ports on the SCV. If I had, it would have simplified a couple of tube bends. I had some complex 3-D bends that could have been 2-D bends.

When I did the mockup I checked for interference with all my attachments. The first time I hooked up my BH and used it after I had the aux system fully completed and installed, I noticed a small problem. When digging in rocky soils (I have a lot) the BH seat is jarred/shaken enough that even though it makes no contact when sitting with any part of the aux system the edge of the seat where the gasket is, makes contact with the fitting that feeds hydraulic fluid into the aux system gouging the seat edging material a bit. I solved it with putting in a 90 degree bulkhead fitting instead of the straight bulkhead fitting and gained nearly 2 inches of clearance that keeps the seat from being jarred into the fitting while digging. The pictures do not show it but it is the fitting on the upper left as you look forward from the rear.

 

[Furu]

Re: Adding Mulitple Hydraulic Control Valves to the tractor

Part 9
My most recent dealer quote for the JD 4th and 5th SCV (LVB26077) for my tractor was $1250 kit and 6-8 hours labor (I doubt it but that is what they say) at $94/hour thus total price for two SCV's would have been $1814 -$2002 plus tax ($1986.33-$2192.19) and I would lose my FEL controls while the diverter has switched control to the rear ports. Additionally I would not have the extra two SCV's available forcing me to use my third SCV which is reserved for the front end. The last port (that was a spare) will probably go to a hydraulic top link but I am debating that still.

I added up my total and came to the numbers below. I did have a bit extra cost in the tubing as I lost some in the learning process. Especially the 0.625 tubing with the problems I had with bending it. I also had three of the 0.5 diameter tubes that I trimmed several times at very little removal each time and the next thing I knew they were too short. I also ordered extra brazing sleeves for initial practice but they are moderately cheap so not a lot extra cost. The biggest expense was the SCV and the Quick disconnects. Also there are a lot of fittings. If I had gone with NPT I could have gone cheaper but I would not do that and I wanted the QD's that had machined grooves in the body for snap rings on the bulkhead plate and the only ones that I could find come from Deere which drives up the price as does my refusal to use NPT thread on the QD. NPT Quick Disconnects are much cheaper. If I had gone with bulkhead mounted fittings I could have avoided the JD QD'd but they would stick out about an extra 4 inches from the mounting plate and I did not want that plus they were more expensive. Everything was a tradeoff of cost benefit analysis. I got double the capability for much less money, I learned some new skills in the process but I spent time that some would say I could have spent doing something else. Bottom line me and the wife are happy with the outcome and the cost.

Hardware $55.33
Steel $58.15
SCV+ PB plug $397.49
10 female Quick Disconnects $287.02
Hydraulic Fittings and hoses $222.78
Hydraulic Tubing $81.46
56% Silver Braze (expensive stuff) $57.75

Total $1,159.98 Includes all taxes and shipping costs just not my labor