Hydraulic Question

[Soundguy]

</font><font color="blue" class="small">( So I ate the cost and started installing pressure relief’s at the pump )</font>

That works for the honest 'accidents'.. like it looking sealed but not being sealed, etc.

However it won't protect against this:

</font><font color="blue" class="small">( It worked fine except customers would pull the disconnects apart while taking the loader off or the like and let it run for 20 min or so )</font>

Which is plain stupidity... and as you said about 'customer / idiot' proofing... idiots are pretty clever.. hard to trick them.

I'm a fan of hard plumbed lines and integral relief valves setup where you cannot seperate the lines from the relief without opening the oil flow to the outside world.. and -0- back pressure, or fixed threaded inlines that don't just 'look' connected.

I've only got a coule hyd lines on my loader... and I can pop them off with a wrench in a couple minutes.. etc. And i don't blow up pumps.. I figure the trade off of needing a wrench or two and a couple minutes, vs qd's, 1 minute, and a blown pump hang pretty close... Course.. I'm a bit utilitarian when it comes to tractors.. I prefer a gear tranny to those hydro's.. etc.

Soundguy

 

[RonMar]

Since your's is hard plumed to the 4 spool valve, it sounds like you will need to have some custom lines fabricated to add another open center valve into your Hydraulic circuit. Still very do-able, just a little more involved than bolting together some pre-made off the shelf hoses and parts. What you could do is install the extra control valve and put quick connects on the working lines that run to the attachment cylinder. When not used you could connect these together or not as the safety in the control valve would protect from damage if you activated the control with no accesory cylinder attached. The only real question is where to put the control valve. Near the op controls for controlling a toplink while running, or somewhere toward the rear for when you want to run a logsplitter. 6.6GPM is going to make for a mighty slow logsplitter though

Good Luck

 

[Dave_Lilly]

If the hydraulic system is correctly engineered the pressure relief valve is located after the pump and before any demand for hydraulics (i.e. 3PH, FEL or any other hydraulic demand). If the load exceeds pump capacity, the relief valve opens to protect the pump. I have a Ferguson TO-30 made in 1952 that has a port for auxillary hydraulic equipment. When I used this port to run a logsplitter all I had to do was run a return line to the sump, otherwise the relief valve opened when the splitter reached the end of it's travel. I feel that any tractor, whether made in China, India, Japan or anywhere else that does not have the relief valve between the pump and the demand is not engineered correctly. Why would any tractor manufacturer engineer a hydraulic pump that would "Deadhead" and destroy the pump? We aren't talking rocket science here, just simple pump protection.

 

[Soundguy]

</font><font color="blue" class="small">( I feel that any tractor, whether made in China, India, Japan or anywhere else that does not have the relief valve between the pump and the demand is not engineered correctly )</font>

Ditto.. It's like not putting a fuse or circuit breaker in an electric line to a high demand/high capacity electrical system.. just -begging- for a problem.

</font><font color="blue" class="small">( Why would any tractor manufacturer engineer a hydraulic pump that would "Deadhead" and destroy the pump? We aren't talking rocket science here, )</font>

Also ditto. This technology has been around many many decades.. to not have implemented it in a robust design on modern applications shows lack of product development.. that.. or the head bean counter figured they could save 1.5 cents per unit and make it 100% less reliable.. and still sell the tractor. And yes.. 'bean counters' do that sort of thing. I've engineered quite a few systems, and then the bean counters come in and ask you to de-rate the system to the point of making it just barely adequate... then they agressively bid out the parts.. etc.. in the end you have a system that had been designed with sufficient tolerances, etc.. then it was raped down to 'just barely works in ideal conditions'.. then it was built by lowest bidder... And then they wonder why customer satisfaction is not 110% /forums/images/graemlins/grin.gif

Soundguy

 

[bluechip]

The basic design is OK until they added the quick connect splice for a loader. adding the loader is not a problem, the loader valve has a PR valve in it, as does the Power steering diverter and the 3 point lift. so there is a PR valve between the pump and load.... UNLESS the quick connect (which was no doubt added at US request as the Chinese don't use loaders much) is opened while the engine runs.

It is true that there are better ways to provide for plumbing hydraulic accessories, for example a manifold with PR valve and ports for a loader as most modern tractors now use.

The tie rap is a cost effective solution. Solid lines as soundguy suggests is probably even better. most people never remove the loader anyway.

 

[greg_g]

</font><font color="blue" class="small">( shows lack of product development.. )</font>

Let me say first, that I have very little experience working with hydraulics. But I'd like to address this topic from the standpoint of how these tractors/dozers/implements ultimately arrive in America (and elsewhere).

China has something over 1.3 billion people, about 70% of which are engaged in something agricultural. As such, the number of tractors they export is probably a drop in the bucket, when compared to those used domestically. So underneath the "Americanized" look of those comparative few that reach our shores, is still the basic tractor that helps feed those 1.3 billion Chinese. No fancy coachwork, no power steering, no FEL, no power-beyond.....But the important thing is that it gets the job done, for a reasonably small investment.

American buyers want power steering, low profiles, fancy fenders, sprung seats, et cetera. All the American "comforts of home", which are seldom standard fare on the Chinese domestic compact/utility tractor. So the American importer goes to the Chinese producer and says "I want this and I want that, but I want it cheap".

Importers aren't engineers either, and the Chinese simply provide what's requested - cheap. To achieve a low profile, the air filter assembly had to be moved. Result? Lousy airflow through the radiator. Sprung seat? Here's one with interior grade vinyl, but it looks like a Grammer. Fenders? Well, you didn't say they had to fit with a FEL too....Backhoe? Well, you didn't ask for a sub-frame...Power steering? Sure, we'll just splice it in. Relief valve? Hmmm, well - you didn't ask for one of those either.........

The importer gets just what he asks for (cheap), the end result of which have sometimes caused consternation for both the buyer - and the Chinese manufacturer. But the feedback method is working. Slowly, but it's working. Responsible dealers/importers provide customer feedback to the manufacturer, and changes/improvements are often quickly implemented.

But don't expect the price to stay the same. Importers thought the market had room for a cheap compact/utility tractors and dozers and implements, and that's what they provided. Emphasis on cheap. They're getting better, but - as in nearly everything else in this world - you get what you pay for.

//greg//

 

[JerryG]

You are probable right about it having quite a bit to do with the importers. If the manufacturer had to deal with the end consumer, it would all change. They would be the one having to deal with the headaches.
What I can't understand is why no one has been able to fix this at the manufacturer level. This has been going on for a long, long time. It has been a problem ever since the Jinma have been shipped to the U.S.. Maybe it is because of all the money that is there to make from new pumps.

 

[Soundguy]

</font><font color="blue" class="small">( But I'd like to address this topic from the standpoint of how these tractors/dozers/implements ultimately arrive in America (and elsewhere)........ So the American importer goes to the Chinese producer and says "I want this and I want that, but I want it cheap".
)</font>

I believe you 100%... In this case, that importer assumes the role of the 'bean' counter ( the one who usually mucks the stuff up /forums/images/graemlins/grin.gif ) that I refered to in my previous post.

All those additions would account for post production engineering.. ( bad post production engineering I.E. with little product development in mind .. I.E. weld something on so we can fix it/sell it..).

Ever get an electronic mother board from an early revision series.. and see re-fit wire soldered all over the thing? and then look at a later revision and see a different copper trace layout? That's a good example of post engineering additions, ( and other issues.. like dealing with HEF's and undocumented features.. etc ).

Soundguy

 

[EFC]

All manufacturers have plumbed hydraulics this way at one time or another it is not a Chinese only problem. I have only seen one or two models of grey market machines with relief’s right off the pump. Hard mounting the valves and only putting disconnects on the working ports is a good fix and we have done that if the customer wants to pay for it. Most don't

Buck

 

[Soundguy]

</font><font color="blue" class="small">( All manufacturers have plumbed hydraulics this way at one time or another it is not a Chinese only problem
)</font>

I didn't mean to imply that it was a chinese only problem. As I mentioned.. usually you see 'under-engineering in 2 cases.. where money dictates finished product.. or in cases of poor product design. I think it's already been hammered out that in this case.. the demand for xxx features at x money is the prime cause for the working yet subtly flawed ( brittle? ) hyds setup in question...

</font><font color="blue" class="small">( I have only seen one or two models of grey market machines with relief’s right off the pump. )</font>

Relief doesn't have to be integral to the pump to be 'idiot proof'. Any relief plumbed in such a way that you would have to modify or defeat the oem system to cause a failure is acceptable. An example would be having the hyd flow channeled via manifold or permanent hard line to a valvving body with integral relief. AFAIK.. yanmar are like this.. with the relief being in the hyd section aranged with an unloading style valve and hardlines from the pump... ford NAA/ hundred series and up used this method. Previous to the ford hundred series, N and all ferguson system tractors, there was a relief integral to the pump due to input valve design..

All but impossible to defeat the relief without mechanical intervention.. like crimping off the feed line, or plugging the exhaust side of the supply manifold.

I favor a robust design and safety vs saving 30-50 dollars worth of connectors and asst hardware, and 5 minutes of install time..

Soundguy