Convert Chinese Backhoe to Prince BH Control Valve Assembly?

   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #1  

Smalljobs

Gold Member
Joined
Mar 8, 2009
Messages
350
Location
Massachusetts
Tractor
Jinma 284
My self imported HW04 frame mounted hoe is finally debugged and has given me good service, especially with the BRO-TEK thumb. Last year I used the BH a lot, including building a wall with the thumb.

THUMB.jpg Wall.jpg

The one complaint I have is the control valve assembly and I don't know if the problem is me or the valve. The extensive stone work involved a lot of bucket curling/uncurling which entailed plenty of lateral joystick movement with my right arm. In late summer an old tendonitis problem resurfaced with that arm and, after physical therapy and all that, the problem persists. This summer and fall, I plan a lot more BH work and am thinking of replacing the entire valve assembly.

I have the ability and knowhow to change over all the hose connections to mate with JIC on a Prince (or other brand name valve assembly) but have some questions about this project:

1) Has anyone had any experience with making the valve assembly change?

2) Can anyone recommend an assembly other than Prince?

3) Are the assemblies such as Prince likely to require less effort on the joysticks than the Chinese valves?

4) What other benefits might I see with improved valves?

If I do go forward with this, I will be selling the Chinese valve assembly complete with a boxful of extra spare parts for the joystick linkages.
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #2  
Probably the biggest advantage will be the gaining of load checks on the individual circuits. This would eliminate the uncommanded opposite movements you sometimes get when moving weight around and trying to perform multiple movements on the chinese valves. IE: you try and curl bucket up and swing and the heavy bucket actually drops as the fluid flows out of hte loaded bucket cylinder and into the less loaded swing cylinder. I don't hardly notice it anymore as I have trained my muscles to just not do certain combinations. But if I could do those combinations together, I could work a little faster.

I don't know if you will get any significantly reduced stick forces with the new valve. The joystick configurations will probably be more precise and you can always add longer sticks which would reduce forces.
I thought about this at one time, and would like the advantages it would give, but I can't justify the time or expense right now. In your case though if it will help with your health, it might also be worthwile to consider if a different configuration might be easier on your medical condition. When I was looking into it, I looked at using 3 different 2 spool valves instead of one large stacked valve assembly. It would have been a little less expensive this way and would have given me the advantage of placing the separate valves in more comfortable locations for operation.
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly?
  • Thread Starter
#3  
RonMar - First, I want to thank you.

To Others: RonMar is a reliable resource and technically knowledgeable on such matters. He has a lot of experience and has posted links and articles to help all of us

Although I don't (yet) fully understand the hydraulics of what he explained, I'll have to educate myself about such things about fluid flows and movement. I'm sure he's right and it's my job to figure it out.
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #4  
I converted my loader to a Prince valve and am very happy with it.

Speeds up operation since you can do 2 operations at once like lift and curl.

Your hoe should see the same improvement.

Cleat
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #5  
Greetings Steve.
When I changed my dozer hydraulics over to US made hydraulics I used Prince and Brand components.
You will notice a difference in the amount of effort required to move the valves, and also the ease of feathering for more accurate control. Another added benefit of using domestic valves is part availability and customer service. There are literally dozens of domestic hydraulic valve manufacturers. Some have proprietary features and options that others don't, but most all of the backhoe stacks are going to be real close. I would suggest getting one equipped with an electric power beyond option to you can operate the thumb with a switch on the joystick.

BRAND Hydraulics suppliers of hydraulic valves and pumps

Surplus Center has a couple of these available. 6 SPOOL HYD VALVE W/JOYSTICKS PRINCE SV
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly?
  • Thread Starter
#6  
Bob,
Thanks for your input!

I've got some ideas how I might convert the Chinese ORF seal ends to connect to JIC or else I might just change all the hoses by making my own. My thought is to remove all the Chinese connectors that screw into the valve block and weld JIC/inch type connectors on them, allowing me to reconnect the hoses "as-is" directly to the Prince assembly.

I've been a critic of the poor quality of these Chinese BH because I had my share of problems with missing parts, broken parts, wrong parts, etc.; however, Jinma made good on all of them. There are still a few weak points that I'll need to address later but in the end, it was still short money to have a 7 foot frame mounted (HW04) hoe with huge cylinders on it. I paid around $2200 for it landed at the local port plus some local trucking. If I go ahead with the valve change, the total investment will still be around $3200 so I can't complain.

If I go ahead, I'll post pictures of the progress.
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #7  
In all fairness Steve, I must admit that I sold the backhoe in favor of an excavator w/a thumb that has four buckets and a rake.
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #8  
I modded my JW03 hoe first year by welding on 6: extensions so I could stand and work it easier (like you) I found it hard to run a lot on the arms. You have to move MORE but feathering and the movement is easy. It only took about 20 min start to finish for me to do the job. I also marked BOTH sticks for Front Rear and Left/ Right as I welded them wider apart and cocked backward some. This placed them in easy reach, what I have been doing is folding the ROPS and setting on it while working it. I replaced my factory JM seat right off with a springer from TSC so that eliminated the rotating seat which just didnt fit my body frame well...

Looking for pics of the mod for ya & finding some

this is hose coming apart from this past summer of yanking on 1000lb rocks w mine


for comparison a JD 4400 with a 430 loader to my 284 & jw03 back hoe w zl20 fel.


can't locate any of the pics of the handle mods but maybe sometime I'll try & get some more..

M
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly? #9  
O/T and no offense to anyone...

Anytime I hear the words "Chinese Backhoe"...it reminds me of an old (not politically correct) construction joke...about a Chinese Backhoe and a Mexican dump truck...meaning a shovel and a wheelbarrow...!

Since I'm already (indicated) Off Topic...here is another one

A young nun was watching some construction workers doing some work on the convent...after hearing some "earthy" language from the workers the nun went to complain to the mother superior...who told the young nun that in the ways of the world and the toil involved with hard labor the men were probably just calling a spade a spade...Oh NO exclaimed the nun...they call it a #%^&*$! shovel...
 
   / Convert Chinese Backhoe to Prince BH Control Valve Assembly?
  • Thread Starter
#10  
Spiker -Thanks.

Somehow Jinma screwed up when they shipped me the BH because it's too far away to use a swivel seat and too close to add a 2nd seat. I usually sort of stand on the tank and lean against the back of me seat or else I clamp a 2X6 across the fenders and sit on it. I like your idea about making the control rods longer and I could offset them to make them closer.
 
 
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