B3300su Hydraulic Pressure Relief
- Thread starter dtherrien
- Start date
OK. I should learn to check the book first.:banghead:The B's are different from the L's. There is a relief for the 3pt that is adjustable. It is part of the 3pt valve and factory specs are 1960-2070 psi which is lower than the rest of the system. It is a bit involved checking the pressure as it requires a special fitting. Unless you suspect the 3pt to be low I would leave it alone.
Sorry about that JJ. :ashamed:
Sorry about that JJ. :ashamed:
J_J
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The first valve with a relief valve will set the high pressure limit for the system.
The other relief valves can be set equal or lower.
The other relief valves can be set equal or lower.
I looked in the owners manual and there is no hydraulic block when there is a loader valve built into the tractor.
If there isnt a loader valve then with the hydro block, it says no relief valave in the block.
So JJ with what you are saying does the backhoe have a way to adjust the pressure relief. I have three owners manuals that came with the tractor...one for the tractor, one for the loader and one for the backhoe. The specs in the tractor manual and loader manual call for pressure relief of 2205psi. No specs on what the pump actually produces. The backhoe manual has no specs for pressure relief...so does this mean it is controlled by the power beyond at the loader valve?
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If there isnt a loader valve then with the hydro block, it says no relief valave in the block.
So JJ with what you are saying does the backhoe have a way to adjust the pressure relief. I have three owners manuals that came with the tractor...one for the tractor, one for the loader and one for the backhoe. The specs in the tractor manual and loader manual call for pressure relief of 2205psi. No specs on what the pump actually produces. The backhoe manual has no specs for pressure relief...so does this mean it is controlled by the power beyond at the loader valve?
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That is correct. The relief in the loader does the whole system except for the 3pt which has it's own.
J_J
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The first relief valve in series will set the relief high pressure.
The hyd block on some tractors have a hyd relief.
The fluid could go from the pump through the hyd block valve then to the FEL valve, and then to remote valve and 3pt. My hyd block has a relief. It is the first relief valve.
Look at your BH valve for a relief . It should be close by the IN port.
Most BH valves have a hyd relief valve.
Show us a picture of the BH valve, or show the valve manufacturer and model number.
If it does have a relief, and it probably does, it should be able to handle pressure up around 2200 to 2500 psi. It should be set equal to the FEL relief pressure.
If you install a hyd gage in the IN port of the FEL valve, or hyd block, then if you use the BH, you will see the pressure the BH is developing.
The hyd block on some tractors have a hyd relief.
The fluid could go from the pump through the hyd block valve then to the FEL valve, and then to remote valve and 3pt. My hyd block has a relief. It is the first relief valve.
Look at your BH valve for a relief . It should be close by the IN port.
Most BH valves have a hyd relief valve.
Show us a picture of the BH valve, or show the valve manufacturer and model number.
If it does have a relief, and it probably does, it should be able to handle pressure up around 2200 to 2500 psi. It should be set equal to the FEL relief pressure.
If you install a hyd gage in the IN port of the FEL valve, or hyd block, then if you use the BH, you will see the pressure the BH is developing.
J_J
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dtherrien ,
If the tractor came with out a FEL, it may or may not have a relief valve on the hyd block.
If no hyd block, the only relief valve would be on the 3pt, and you could not connect your BH with out a relief valve, so the BH has to have a relief valve. The BH relief valve becomes the main relief valve.
There are external relief valves to add to a hyd circuit if you need them. This will protect the pump.
If the tractor came with out a FEL, it may or may not have a relief valve on the hyd block.
If no hyd block, the only relief valve would be on the 3pt, and you could not connect your BH with out a relief valve, so the BH has to have a relief valve. The BH relief valve becomes the main relief valve.
There are external relief valves to add to a hyd circuit if you need them. This will protect the pump.
JJ,
I am 100% positive that the loader valve is part of the standard equipment of the b3300su. It is right below the heel of my right foot. I am thinking the loader valve is the main relief ...in the manuals its the only one with specs.
I will take a picture of the loader valve and backhoe valve this weekend.
I am 100% positive that the loader valve is part of the standard equipment of the b3300su. It is right below the heel of my right foot. I am thinking the loader valve is the main relief ...in the manuals its the only one with specs.
I will take a picture of the loader valve and backhoe valve this weekend.
You are correct, the loader valve is the only relief for the system. It is also the PBP for any other add on's and also supplies pressure oil to the 3pt.
J_J
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