LB1914 - turning up the pressure

gladehound · Apr 2, 2008

If yours is like mine, the pressure relief adjustment for the loader is right next to your loader joy stick on the top of the Prince valve. There will be an adjustment screw and it is kept from moving by a nut. Unfortunately for me, I broke the adjustment screw by tightening the nut to much. So be careful. I think you should be able to adjust the loader pressure up by turning the adjustment screw clockwise until when you max out the loader, you hear the system relief open instead of the loader relief. Since I broke mine I haven't played with it much. I ordered a new pressure relief for about $20 but it hasn't arived.

The other pressure believe is on (I think) the valve body under the right side of the seat. I do not know if this is the screw type or the shim type of what. If you are going to mess with this, I think you need a gauge because if you go to high without knowing it you could break something (pump?, 3 pt cyclindar? loader? you name it).

Once I get the new loader relief I'll probably just adjust that up until I'm going off the system relief. But at some point I want to set the system relief and the loader relief both to open at 2300 psi with a gauge to have redundant protection for the pump which the manual says is rated for 2350 psi. However, i probably wont crack open the system valve without the help of someone who knows something about these valves. (not me).

Don't let the last Email full you. I'm good at the math. But I've never done any wrenching with hydaulics. As you read, I already broke the loader relief adjustment. I only broke the adjustment. The loader still works fine and is strong enough to lift a rear wheel (filled rears) with no implement on the back if I hook the corner of the bucket on a root or big rock.

I do intend to figure all this out (with the help of my friends!) and once I do I will post the details with pictures. But it's not a high priority right now since the tractor is doing what it needs to do. I'm digging out for a garage foundation and the loader is strong enough for that. I often have to back up a hair to break the bucket out but with the new tooth bar it really digs!

cgraham · Apr 2, 2008

Thanks for all the detail. Please do post any progress.

I'm trying to finish rebuilding my 1/2 mi. driveway right now, and don't want to take time out to fiddle with it until the job is finished and I know what I am doing. I'd hate to mess something up in the middle of the job!

Charlie.

gladehound · Apr 2, 2008

Charlie,

Will your loader currently lift a back tire if it gets caught on a rock or something? Just trying to get a feel for if you pressure is set too low.

Ron

cgraham · Apr 2, 2008

Lacking a rock, I wedged one corner of the blade against a large tree and tried to unplant it while in neutral. Much moaning and groaning, but not the slightest sign of a rear wheel lifting (or the tree for that matter).

My tachometer shows my highest rpm as 2400; the manual says 2600; either the tach is out of calib, or the throttle needs adjustment. I don't know that 2000 rpm would make a big difference in this situation, though.

Maybe the pressure IS set too low. But bear in mind that my tires are filled with foam, which weighs about 1000#, I think.

Charlie

gladehound · Apr 2, 2008

Well the last time I lifted a wheel (Satuday) I was at 2200 rpm. But mine will run at 2800 rpm WOT. Don't know what my rears are filled with. They were filled before I got it. Whatever it is, it leaves subtantial residue behind when it dries. Comes out a little sometimes when I add air to the tire because I am too lazy to rotate the valve to the top.

The rears of the LB1914 take around 5 cubic feet of fill. If you have 1000 pounds in there that foam is more dense than granite. Hard to believe. With winshield wiper fluid it adds around 300 pounds. Probably the lightest option. I've always heard that CaCl is the heaviest option and that is around 540 pounds.

I have lifted a rear even with my carry all, box and some chains all on the 3pt. That's about 200 pounds in addition to the filled tires. And the weight on the 3pt is further back. So regardless of what's in your tires, I think you should be able to lift one if the bucket corner is stuck on something. Now if the middle of the bucket is caught it will not lift the entire back end. I'd guess your pressure is a little low. But who knows, maybe the last owner of my tractor already turned up the pressure and mine is high. Need a gauge.

kennyd · Apr 2, 2008

You guy's are crazy if your adjusting the relief valve without a pressure gauge-something I only read mentioned once in this thread! A pressure gauge setup will only cost about $35.00 to setup, and MUST be used to properly the the pressure to spec. Playing with the relief valve just to gain more lift without knowing the pressure is a ticket to a expensive and possible dangerous failure.

All you need is a gauge that can read to 3000PSI, a short 1/4" hose, and a QD nipple that fits into one of your FEL QD ports, then operate the joystick to energize that QD sending the system into relief so you can read the pressure.

SPYDERLK · Apr 2, 2008

gladehound said:
If yours is like mine, the pressure relief adjustment for the loader is right next to your loader joy stick on the top of the Prince valve. There will be an adjustment screw and it is kept from moving by a nut. Unfortunately for me, I broke the adjustment screw by tightening the nut to much. So be careful. I think you should be able to adjust the loader pressure up by turning the adjustment screw clockwise until when you max out the loader, you hear the system relief open instead of the loader relief. Since I broke mine I haven't played with it much. I ordered a new pressure relief for about $20 but it hasn't arived.

The other pressure believe is on (I think) the valve body under the right side of the seat. I do not know if this is the screw type or the shim type of what. If you are going to mess with this, I think you need a gauge because if you go to high without knowing it you could break something (pump?, 3 pt cyclindar? loader? you name it).

Be very careful here! The way you are describing it it sounds as if the system relief may be after the loader relief. It is that way on my Mahindra. The system is fed from the loader Power Beyond. If this is the case, and you turn up the loader relief your loader will operate on that new relief pressure. Your system relief will not come into play except when you use the fluid coming from the PB. On mine there is no relief at the pump. The 1st relief in the pressure line is the one in the loader valve. This means that if the loader relief is set too high it will blow the pump with no regard to the lower setting on the system relief. Turning the loader screw in 1 turn should be safe. And thats just a guess. you really need to gauge it .
larry

gladehound · Apr 2, 2008

Larry - You may be right. Looking at the hydraulic system schematic in the 1210 loader manual it shows the pump pulling from the reservoir and sending fluid first to the loader valve. The loader valve power beyond goes to the tractor system and then out to the fluid reservoir.

However, the diagram doesn't indicate where the auxilary flow divider valve is in the system. And in the instructions to set up the loader, the line going into the loader valve is from the pressure port of the auxillary flow valve. There is a control knob on the auxillary valve that has to be turned full clockwise to use the loader. The manual says that if the pressure port (the one the loader uses) is not in use (i.e. plugged) and the control knob on the auxillary valve is turned clockwise, the relief will operate. Therefore, if pressure to the loader gets too high the system relief will operate also. So it sounds like the system relief must be before the loader.

The LB1914 manual lists a pump safety relief operating specification at 2256 psi and a system relief operating specification at 2130-2230 psi. So does that mean with the loader there are three separate relief valves? One at the pump, one at the auxilary valve for the system and one at the loader? That's what it sounds like. If this is true than the pump relief valve opens if all else fails, but the system relief should open before that even if the loader relief fails to open.

Maybe on the weekend I will trace all the hydaulic lines and see where they go and see if I can find a relief valve on the pump as well.

And yes.... I am crazy

SPYDERLK · Apr 3, 2008

gladehound said:
Larry - You may be right. Looking at the hydraulic system schematic in the 1210 loader manual it shows the pump pulling from the reservoir and sending fluid first to the loader valve. The loader valve power beyond goes to the tractor system and then out to the fluid reservoir.

However, the diagram doesn't indicate where the auxilary flow divider valve is in the system. And in the instructions to set up the loader, the line going into the loader valve is from the pressure port of the auxillary flow valve. There is a control knob on the auxillary valve that has to be turned full clockwise to use the loader. The manual says that if the pressure port (the one the loader uses) is not in use (i.e. plugged) and the control knob on the auxillary valve is turned clockwise, the relief will operate. Therefore, if pressure to the loader gets too high the system relief will operate also. So it sounds like the system relief must be before the loader.

The LB1914 manual lists a pump safety relief operating specification at 2256 psi and a system relief operating specification at 2130-2230 psi. So does that mean with the loader there are three separate relief valves? One at the pump, one at the auxilary valve for the system and one at the loader? That's what it sounds like. If this is true than the pump relief valve opens if all else fails, but the system relief should open before that even if the loader relief fails to open.

Maybe on the weekend I will trace all the hydaulic lines and see where they go and see if I can find a relief valve on the pump as well.

A relief at the pump would be wonderful - built in forgiveness of an error down the line. Im glad you will be tracing your system out well. Knowing how the various, and sometimes hidden, controls operate and interrelate is very important when changing anything. That aux flow divider valve sounds interesting and deserves a good look.
larry

gladehound · Apr 3, 2008

Got my new pressure relief catrige for the loader last night and installed it today. It seems you get about 800 pounds of break out and 400 pounds of full lift for each full turn of the adjustment screw (includes weight of bucket and loader arms). So it took 3/8 turn just to get the bucket off the ground empty and 3/4 of a turn to get it to full height. At around 3 turns total one of the other reliefs starts to kick in. I didn't get much more lift. Maybe an extra 100 or 200 pounds at break out. I can now barely lift a rear wheel if the corner of the bucket is caught and I have my rear blade on. I don't think it ever lifted are rear with the rear blade on before.

Digging the foundation a little more today. I weighed the dirt in a bucket. 13 pounds per gallon. I think that's about 100 pounds per cubic foot. I had some heaped bucket loads and it had no problem going to full hight so it can lift 900 pounds or so. So the pressure is probably a touch over the 1900 psi specification for the loader from the factory. I still frequently have to back out a touch to break the bucket out when digging in compacted dirt.

I'd like more break out but unless my system is set low, which it can't be by much, i'm not going to get more without bigger cyclindars.