Hydraulic pressure question on new L2501

Tornado

Well-known member
May 7, 2019
793
254
63
usa
Being a new L2501 owner Ive spent considerable time reading lots of posts both from here and elsewhere, watching videos, and just generally consuming knowledge on my new tractor. One thing Ive come across on several occasions is the issue of Hydraulic pressure, specifically in regards to the FEL on Kubota tractors. I have read that kubota tractors, when tested, often report lower than spec hydro pressures. Ive also read about people increasing their pressure a little beyond spec. What Im wondering is wether it would be worth it for me, as a new tractor owner, to invest in a hydro pressure meter and potential adjust it. I have no real desire to go above the spec, but if it is low as I have read in places perhaps it would be worthwile. I guess my qestion is how common is it to see the hydraulic pressure be low and need adjustment? Should I just leave it alone? BXpanded has a nice pressure test and adjustment kit for $70. Im tempted to get it. Im just curious how common low pressure is, and maybe if some could speak to how quickly this pressure tends to decline over time. I have read that over time the pressure will drop in the FEL due to the spring wearing in. Again, my only goal is to stay right at spec pressure, I am not wanting to push beyond spec.
 

Dave_eng

Well-known member
Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,235
1,018
113
Williamstown Ontario Canada
It makes no sense to mess with a perfectly working, new, under warranty tractor. You have a far greater chance to run into warranty issues by putting your hands on the machine.

The hydraulic systems are often more complicated than owners appreciate. For example, on many, hydraulic power is taken from a loader valve, using a power beyond port, to feed the 3 pt hitch and rear remotes.

In this scenario, there are two pressure relief valves. One in the loader valve and another at the rear of the tractor. Since the relief valves are, in effect, in series, whatever you do with the rear one, you cannot adjust it higher than the front one.

As far as measuring pressures is concerned, gauges have accuracy limits and the best ones cost as much as your tractor. The science of measuring anything is called metrology and it is a science unto itself.

A typical low priced gauge will have an accuracy of + or + 5% of its full scale number. So a 0-3,000 psi gauge could be reading 150 psi higher or 150 psi lower than you see on the dial. That is a range of 300 psi.

Leave things alone unless you experience performance that clearly falls outside the published values. Then, until you are taught, leave the adjustments to a trained mechanic.

Dave
 

PaulL

Well-known member

Equipment
B2601
Jul 17, 2017
2,440
1,365
113
NZ
I'll sort of agree with Dave, and sort of disagree.

I wouldn't play with your pressure unless there's something you want to do that you can't. If you're regularly trying to lift loads that your loader doesn't want to lift, then it makes sense to look at whether it's working properly. But if it's doing everything that you need it to do, then you're playing with a working thing, and you may change it to no longer be working.

Having said that, for many people (myself included) a tractor is one of your toys, and there's no reason not to play with your stuff. Plenty of people spend time modifying their cars to have more HP, and some people will say "you'll break that", but there are whole communities of people doing it. It's your tractor, if it makes you happy to tweak it, then go ahead and do so. And yes, it may cause warranty issues if you break it, but so long as you are aware of that then go ahead. $70 isn't much for a kit to measure it, and there's probably a whole day of fun in playing with it.

Of course, there's a bit of me that says most people buying an L2501 aren't the kind of people who need the last bit of power, its reputation is as a solidly built tractor operating well within its limits. If you wanted more power you'd have bought a more powerful machine.
 

greenacresnorth

Active member

Equipment
L2501,BH77
Feb 18, 2018
175
28
28
38
Morganton,NC
In this scenario, there are two pressure relief valves. One in the loader valve and another at the rear of the tractor. Since the relief valves are, in effect, in series, whatever you do with the rear one, you cannot adjust it higher than the front one.
nope, only one system relief. PB is nothing more than a flow divider combining fluid coming off a valve and combining it with excess flow from pump. in the several hundred machines I have PDI'd ranging from Cat skidsteers, Farm tractors, Cranes, loaders, excavators.... very few will make rated relief from the factory. rated pressure is a statistic stated by the designers, a valve is spec'd and sourced by the OEM, installed and machine tested as a whole. if the cycle times and other test parameters are met at the factory then tractor/machine goes out the door. I check and set all pressure on every machine I put into service, it doesn't take a $10,000 gauge or any special tools, just a decent set of gauges and fittings, +/- 150-200 psi is more than good enough.
 

Sammy3700

Active member

Equipment
L3800HST,524Loader,BH77,Landplane,Disk,Mowers and more
Feb 20, 2012
437
41
28
Red Springs, NC
I agree I have done several L series and a good liquid filled gauge from the hydraulic store a female quick connect and you are set
 

Tornado

Well-known member
May 7, 2019
793
254
63
usa
nope, only one system relief. PB is nothing more than a flow divider combining fluid coming off a valve and combining it with excess flow from pump. in the several hundred machines I have PDI'd ranging from Cat skidsteers, Farm tractors, Cranes, loaders, excavators.... very few will make rated relief from the factory. rated pressure is a statistic stated by the designers, a valve is spec'd and sourced by the OEM, installed and machine tested as a whole. if the cycle times and other test parameters are met at the factory then tractor/machine goes out the door. I check and set all pressure on every machine I put into service, it doesn't take a $10,000 gauge or any special tools, just a decent set of gauges and fittings, +/- 150-200 psi is more than good enough.
Appreciate the good reply here and your personal experience. Im not a mechanic and I knew just from my little reading that what dave said above didnt sound right.

I work in technology. I remember when I was young everyone telling me computers were complex and I shouldn't mess with them when they stopped working, and instead only allow a certified technician touch it. Thankfully I ignored that advice. I was building and overclocking computers at 13 years old. 25 years later and its now funding my life. I can respect the advice of "dont mess with something thats working fine" thats good logical advice and I appreciate that but by trying to make things sound overly complex you end up giving inaccurate information. That's not very helpful or useful.
 

Nicfin36

Well-known member

Equipment
L2501 HST, BH77 Backhoe, SSQA Loader ZD1011 Mower
Jun 19, 2019
1,016
466
83
Decatur, AL
Tornado, I have had the same thoughts cross my mind on my L2501. I had no intentions of meddling with anything at the moment, just reading and watching videos like you. I have not used my loader very much, but I did move a bunch of dirt by digging into hard ground and I never felt the loader was really underpowered. But, we all wonder if it could do just a little bit more. I don't have my grapple yet, and I think that will be a good test on the loader. I too have seen the kits on BXpanded. If you do decided to check it, I would be curious to find out what your pressures are.
 

edritchey

Well-known member
Lifetime Member

Equipment
A bunch of cute little Kubotas
Jul 19, 2014
1,107
806
113
Wellsville, PA
I had a L3901 and it didn't preform as well as I thought it should so I asked the dealer to check it out and they told me it was within spec.

I did some test with known weights on skids and it was lifting what it was rated for but I wanted to get it to do a little better and after reading all the post of people adding shims and getting better lifting capacity I decided to try it for myself.

I bought a real nice test gauge setup from Kenny at bolt on hooks and it showed my pressure being a little on the low side so I added some shims that put it just over the high end of the range as listed in the WSM. But I only gained a very slight amount of lifting capacity. I could lift a skid with 200lbs more on it but it couldn't tilt it back once lifted off the ground.

I ended trading the machine in on a MX series because I needed more lifting capacity to do the work I wanted to do around my place. In the end I wished I would have done my homework on the tractor specs prior to buying the L3901.

I still have a few unused shims that should fit the L01 series tractors if anyone wants them PM me with your address and I'll send them out to you free of charge but don't expect them to make a huge difference in you loader capacity they just don't.

Good luck with your loader unfortunately it's only as good as Kubota said it is if you need significantly more lifting capacity you're going to need a bigger machine. :eek:
 

greenacresnorth

Active member

Equipment
L2501,BH77
Feb 18, 2018
175
28
28
38
Morganton,NC
Appreciate the good reply here and your personal experience. Im not a mechanic and I knew just from my little reading that what dave said above didnt sound right.

I work in technology. I remember when I was young everyone telling me computers were complex and I shouldn't mess with them when they stopped working, and instead only allow a certified technician touch it. Thankfully I ignored that advice. I was building and overclocking computers at 13 years old. 25 years later and its now funding my life. I can respect the advice of "dont mess with something thats working fine" thats good logical advice and I appreciate that but by trying to make things sound overly complex you end up giving inaccurate information. That's not very helpful or useful.
my dad always told me that having a diploma on the wall doesnt make you smart. i graduated collage with some of the dumbest people i know........ being a engineer and a tech gives me a view of both sides of the coin. when someone tries to tell you how complicated something is, its there way of trying to make you feel dumb and justify there position at the same time.
 

Tornado

Well-known member
May 7, 2019
793
254
63
usa
I'm late getting back to my thread here but appreciate all the good replies. I don't think I'm going to mess with anything for now. I was toying with the idea because it seems like a fairly simple adjustment, but It seems the real world results, even if I did bump it a tiny bit isn't going to be noticeable.
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,207
1,893
113
Mid, South, USA
Hydraulic systems can be real dangerous.

"case" in point-MX5100, guy was using it to pick up cars (fork attachment) at a junkyard. It was borderline. It'd pick up the shells of most compacts but bigger stuff no way, so he says hey I need to check the hydraulic pressure. Grabs an internet chinese gauge, hooks it all up, cranks the tractor up at idle, sure enough it's low. Ok, I'll crank 'er up to where it needs to be. Fine, it works a little better now. Then one afternoon he's got the bush hog hooked up, working around the place, backs it down in a ditch and gets the tailwheel jammed into the other side of the ditch bank. Grabs the 3ph lever, pulls back, big crack and lots of oil peeing out everywhere. AT idle the pressure was within spec. Little did he know, on that tractor it is rated at a certain psi at a certain engine speed, thus at idle it was low....at rated RPM it was probably pretty close. But after adjustment at idle speed it was "correct", but once it was at rated engine speed, it was probably 1000 psi higher than spec. There was enough force on the 3ph cylinder to completely explode it which took out the 3ph cover assembly, ring gear, pinion gear, transmission case, and a bunch of other stuff. That's why I said, hydraulic systems CAN be dangerous-particularly to those who aren't 100% sure of what they're doing.