Is hydraulic pressure deliberately set "low" from the factory or dealer?

joea

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B21 TLB
Aug 2, 2020
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Title says it all.

Found the pressure on my B21 to be about 1800 psi and adjusted it to 2000 psi which is the "factory spec".

From what I've read it is very common for machines to be found 200-300 psi lower than factory and was wondering why?
 

DustyRusty

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Nov 8, 2015
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When I had my old BX in for service of the hydraulic system the service department wouldn't raise the pressure from the original factory setting of about 1400 PSI. I was going to do it myself but I sold the tractor when I bought a BX23S. That one the original setting is 1750 plus or minus. I have the shims and the gauge, just waiting for cooler weather to do the hydraulic fluid change, add the wheel spacers, and the 200 hour maintenance servicing.
 

TheOldHokie

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Title says it all.

Found the pressure on my B21 to be about 1800 psi and adjusted it to 2000 psi which is the "factory spec".

From what I've read it is very common for machines to be found 200-300 psi lower than factory and was wondering why?
The vagaries of manufacture and assembly. Pressure is probably calculated based on the specifications for the spring and poppet size then simply assembled without any additional calibration.

My L3901 is right on the money. Who knows what your 20 year old machine was when it was new.

Dan
 
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bbxlr8

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L2501 w/R14s, LA525, BH77, SGC0660, CL 5' BB, CL PHD, WG24 + Ford 1210 60" mmm,
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The vagaries of manufacture and assembly. Pressure is probably calculated based on the specifications for the spring and poppet size then simply assembled without any additional calibration.

My L3901 is right on the money. Who knows what your 20 year old machine was when it was new.

Dan
My 2501 was also right on published spec. which is under L33/39 with same H pump and loader. I judiciously bumped up based on a survey of input here. I was conservative at first and couldn't be happier with the results. Felt no need to adjust further so far.

Now the artificially low rev limiter is future fair game after warranty is up ;) but even that is not an issue now based on my use.
 
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GreensvilleJay

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Hope you're using a KNOWN, CALIBRATED pressure gauge to take the readings ! I had two in the drawer and they were off by 100#. Great WHICH is correct ? Took to the lab at work, guy confirmed silver one good, black case low,so I kept the silver one, tossed other into the bin.
Probably on the low side to be safe. Minor differences in springs, shims, cavities could add up to be OVER the desired setpoint.
 

Yotekiller

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Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Sep 29, 2023
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The vagaries of manufacture and assembly. Pressure is probably calculated based on the specifications for the spring and poppet size then simply assembled without any additional calibration.

My L3901 is right on the money. Who knows what your 20 year old machine was when it was new.

Dan
Dan, what is your take on the mechanical safety of increasing the hydraulic pressure by shimming? In your opinion, Is 2-300 PSI going to cause major issues down the road?
 

TheOldHokie

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Dan, what is your take on the mechanical safety of increasing the hydraulic pressure by shimming? In your opinion, Is 2-300 PSI going to cause major issues down the road?
On a 2500 PSI system 200-300 PSI is a 10% increase in design load. Doubtful that presents any great risk of catastrophic mechanical failure. It might be significant in terms of service life of the pump or other hydraulic components.

Personally I would not exceed the factory pressure specification to get more hydraulic power. Thats an engineered number chosen for a reason. I have no basis to second guess it.

If you need more power get a tractor built for more power. Increasing the size of the cylinders or increasing the mechsnical advantage of the lift geometry gets you more power at the same or lower hydraulic pressure. I would be far more tempted by something like that.

As you might guess I dont spend money increasing the power of my cars with aftermarket tunes either. If I wanted more power in my daily ride I would trade my 3 series BMW for an M series that the factory has engineered.

Dan
 
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Yotekiller

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On a 2500 PSI system 200-300 PSI is a 10% increase in design load. Doubtful that presents any great risk of catastrophic mechanical failure. It might be significant in terms of service life of the pump or other hydraulic components.

Personally I would not exceed the factory pressure specification to get more hydraulic power. Thats an engineered number chosen for a reason. I have no basis to second guess it.

If you need more power get a tractor built for more power. Increasing the size of the cylinders or increasing the mechsnical advantage of the lift geometry gets you more power at the same or lower hydraulic pressure. I would be far more tempted by something like that.

As you might guess I dont spend money increasing the power of my cars with aftermarket tunes either. If I wanted more power in my daily ride I would trade my 3 series BMW for an M series that the factory has engineered.

Dan
Thanks, Dan, for that well explained opinion.

I will admit that I am the total opposite of you, though. I cannot leave anything alone. I'm running 2700PSI on my 2502 and I am eagerly waiting for a turbo kit to come out for it... And I don't even need that extra power :LOL:
 
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TheOldHokie

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Thanks, Dan, for that well explained opinion.

I will admit that I am the total opposite of you, though. I cannot leave anything alone. I'm running 2700PSI on my 2502 and I am eagerly waiting for a turbo kit to come out for it... And I don't even need that extra power :LOL:
Probably reflective of an age difference. My hotrodding days are pretty much behind me.

When I went shopping for my new machine I started looking at B series machines but quickly moved up to the Standard L lineup. Then comparing specs and prices I simply went higher in the lineup - L3901 with a factory engineered and warranted boost in size and engine/ hydraulic power. Coming off a B7200DT it seemed like a massive jump because it was.

In retrospect and having used the L3901 for almost 4 years I probably stopped one model too soon. And had I went one model higher I would probably be thinking the same thing about the L4701.... Its a vicious cycle.

Dan
 
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Yotekiller

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Probably reflective of an age difference. My hotrodding days are pretty much behind me.

When I went shopping for my new machine I started looking at B series machines but quickly moved up to the Standard L lineup. Then comparing specs and prices I simply went higher in the lineup - L3901 with a factory engineered and warranted boost in size and engine/ hydraulic power. Coming off a B7200DT it seemed like a massive jump because it was.

In retrospect and having used the L3901 for almost 4 years I probably stopped one model too soon. And had I went one model higher I would probably be thinking the same thing about the L4701.... Its a vicious cycle.

Dan

Maybe that is it.... I am 51 now and feel like I hit it harder now than I did in my 20's. I think it's because through my 20's and 30's I was doing fun stuff with the wife, or hanging at deer camp with the guys, fishing etc. And now, I just want to be home and get stuff done. Work is what I enjoy now days. My buddies can rarely ever get me off my property.

I went the other direction tractor wise. I actually had planned to buy the 3560 and was seriously considering the 4060 just for the frame size jump. It was set in stone I was buying one of those two tractors. But, I just kept thinking how much I really didn't want an emissions tractor, I wanted minimal electronics and as mechanical as I could get and that was either something years old or smaller. That's what lead me to the 2502. Actually, I was trying to find a 2501 since the turbo was already available for it, but I couldn't find a new or used one anywhere around me. So a 2502 it was... And like you, I knew that no matter what, it would never end thinking I needed a bigger tractor, that I would always find a limit, no matter the starting point...

I can honestly say that I couldn't be more satisfied with my 2502. Sometimes I think how nice the tranny on that Grand L would have been and how quiet it was in the test drive, but then I immediately think how bare bones and minimalistic my 2502 is and I just smile.
 
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TECH101

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Kubota - Bobcat - Caterpillar - Case - John Deere - FARM - CONSTRUCTION -
Mar 8, 2022
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Thanks, Dan, for that well explained opinion.

I will admit that I am the total opposite of you, though. I cannot leave anything alone. I'm running 2700PSI on my 2502 and I am eagerly waiting for a turbo kit to come out for it... And I don't even need that extra power :LOL:
If you over load the pump if will fail much faster and putting extra load on your relief valves can be dangerous

Just saying.........
 
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