You got me under pressure......Kubota BX25D Style.

[Cherokee140]

Well yesterday I mowed with the little thing for the first time, hope do to an update in the day in the life thread later today.....and took everything off the tractor for the first time, well I have had the deck off for a while, but the loader and backhoe came off for the first time....I will also up date that experience in the other thread....but.

I had bought one of those BXpanded pressure testing kits, really just for the heck of it. Well with the loader off I figured hay why not use that thing that you have had sitting around for a month now. So I hooked it up to the loader output, White IIRC, and started to wiggle my joystick Pressure quickly popped up to 1600psi....hmm think that might be a bit low....yup sure enough it is low, max spec is 1800 and change, so I may bump it up. I have not found it wanting in lifting anything, but I am **** about some things and specs are specs. So it looks like I might be tossing a few shims in there. I found it pretty odd that it is that far under the max.....and IIRC it is under the minimum spec, don't remember that number off the top of my head.

So moral of the story is, you might want to check this.

 

[Tractor Seabee]

I made up an in-line gauge with a tee and two mating QCs. I put it in the line from the pump at the BH connections. That way I can see the pressure as it is being used. My BX was a little on the low side also. Bumped it up to 2000 PSI. Made a big difference in what I can lift and the force the BH and FEL can exert. Oh I did that after the 1 year warranty expired.

Ron

 

[texasjohn]

Many have discovered that FEL pressure is low from factory. Personally, increasing to spec was the difference between can and can't for a particular task I have. I recommend you increase pressure to spec via shims. AND to make sure you have sufficient rear weight to handle the full weight of the FEL lift before relief valve pops.

 

[dragoneggs]

I made up an in-line gauge with a tee and two mating QCs. I put it in the line from the pump at the BH connections. That way I can see the pressure as it is being used. My BX was a little on the low side also. Bumped it up to 2000 PSI. Made a big difference in what I can lift and the force the BH and FEL can exert. Oh I did that after the 1 year warranty expired.

Ron

I suppose I will tweak mine with shims when my warranty expires but I have to say that I can lift a full bucket of crushed gravel without problem (okay might have to back off the pile a tad) but still a full bucket. Dialing it up for a little more pressure/power is hard to resist though. Hard not to want to eek out a little more out of your machine whether it be your first 60's muscle car or new tractor.

I kind of miss my teenage days of adding headers, better carburetor, tweaking the timing (weekly), all in a sophomoric attempt to find a little more performance in your ride!

 

[Cherokee140]

I suppose I will tweak mine with shims when my warranty expires but I have to say that I can lift a full bucket of crushed gravel without problem (okay might have to back off the pile a tad) but still a full bucket. Dialing it up for a little more pressure/power is hard to resist though. Hard not to want to eek out a little more out of your machine whether it be your first 60's muscle car or new tractor.

I kind of miss my teenage days of adding headers, better carburetor, tweaking the timing (weekly), all in a sophomoric attempt to find a little more performance in your ride!

I think that is where I get this from. I did heavy American muscle for a long them....then I blew out my back and figured out I am not lifting big block heads at all anymore. So I started on little cars. Then more battle damage, this time with holes and metal now breathing causes pain (really does) I still have the cars, and I still have a few that are part way done, a race car and a VW bug. I like the bug because everything is so light, and it gives me something to tinker on. Some of the cars have not moved since the first gulf war, I know it is bad but I just can't let them go....I keep thinking I will get better, but it really is a pipe dream....should sell all them off and get a new Mustang or Porsche or something like that.

I really thing that is why I want every inch out of my tractor, I don't think bumping it up to within spec will void my warranty...not sure....you have me scarred now so perhaps I will wait. I doubt the extra power will let me bust roots the size of my wrist....have to use a chain saw on those things....and that ticks me off, chain saw + dirt = bad.

 

[texasjohn]

You have the pressure gauge and the skill to add a shim to bring it up to max pressure. I think you should do it...I cannot believe warranty would be voided. Hoses and the rest of the system are well designed to withstand the pressure somewhat beyond the max spec.

 

[Tractor Seabee]

I suppose I will tweak mine with shims when my warranty expires but I have to say that I can lift a full bucket of crushed gravel without problem (okay might have to back off the pile a tad) but still a full bucket. Dialing it up for a little more pressure/power is hard to resist though. Hard not to want to eek out a little more out of your machine whether it be your first 60's muscle car or new tractor.

I kind of miss my teenage days of adding headers, better carburetor, tweaking the timing (weekly), all in a sophomoric attempt to find a little more performance in your ride!

Where I noticed the big difference was in using the FEL w/forks and the 3 PT w/forks. Also the BH is a lot better at break out force with the bucket. I have noticed that the relief valve has become noisier, probably relieving more often. The down side may be early replacement of the valve parts. That is as easy to do as adding shims from what I see in the WSM Page 5 S-4.

I subscribe to Texas John on "get all you can". There is probably a limit somewhere that the increased pressure will overload the FEL arms and cause a failure. It is also more important to keep those heavier loads close to the ground when moving.

Has any one pushed the pressure beyond 2000 PSI? Maybe this is an idea for a new thread.

Ron

 

[rich bx]

HI Guys-
New to the Hydrological mechanics world for the most part.
I hear you guys talking about adding "shims" to increase hydro pressure int he system.
Could somebody explain more detailed (hopefully a pic but I know that's asking a lot, but sure would be nice If I knew which part to add this shim too).
I bought a used bx last year and I thought I should be able to do a little more with the FEL with the forks on it.
It's outta warranty so...

 

[texasjohn]

To be clear, the OP indicated he has the tools and expertise to test pressure and knows where the shim should go. I advocate taking to only max pressure...at most 50 to 100 lbs beyond.

Rich, the hydraulic pump generates pressure to operate the equipment. The hydraulic pressure in the FEL system increases to meet the load requirements until it reaches the pressure which is set in the relief valve. This valve is set to allow some fluid to bypass the system and keep the pressure at a preset level. The valve is basically a needle valve surrounded by a spring keeping pressure on the valve to keep it shut. When the hydraulic pressure exceeds the pressure provided by the spring, the valve opens and fluid flows back to the hydraulic tank, keeping the pressure in the FEL system at a certain level. The relief pressure of this valve is typically adjusted by increasing/decreasing the amount that the spring is compressed. More compression, more pushback from the spring, requires a higher pressure before the valve will open. The shim being discussed is basically a washer slipped over the needle valve and resting on the spring. The thickness of the washer is calibrated to various PSI settings. Key is to have a pressure gauge with which you can determine what the pressure is and what it becomes after modification of the shims. In my case, I took tractor to dealer, they installed gauge, verified that the relief pressure was low, thus not allowing the FEL to pick up as much weight as spec'd. Leaving the gauge attached, they ADDED a shim (mechanic said that while Kubota has specific shims, they didn't have these specific shims and just used a washer which would fit. Thus, pressure was increased to about 100 lbs over max spec because washer was a tad thicker than needed to achieve the perfect number. I impressed on mechanic how careful I am during operation, always using extreme weight on 3ph to counter FEL weight and carrying low and ALWAYS ready to dump load and driving slow...thus mechanic left it at slightly over max spec. Exactly where the valve is on your machine...I don't know, someone else may be able to provide the specific location.

 

[Cherokee140]

Could you link to the Texas John thread you talked about.....

The shims are very thin "washers", IIRC each .1mm will bring the pressure up 40psi. You put the shims under a bolt that holds the spring and check ball and that will make the spring harder to compress raising your pressure....I think the only tool you need is a 20-somthing mm socket. (again all this is from memory) It does not sound like it would be hard.

I think I am going to do it next time the backhoe is off.