NH B-104 back Hoe attach problem.

[kolo]

Back hoe line pressurizes when disconnected. Relieving pressure before disconnecting from skidsteer. Using bleed off pet cock on hoe. every time I have to hook it up I must break the connection of the male flat face , lower Aux. port to relieve the pressure on line or it just cannot be hooked up. the other line goes on very easy. I have had the same problem with 2 separate skid loaders and believe the problem is in the hoe. Any NH mechanics out there. Also which line is pressure and which is return. Which position , down or up is return on the aux. handle in the cab. Can it be some sort of Check valve in the line won't allow pressure to bleed off properly. Any help appreciated. Also note no other problems with other attachments drill, grapple, just the hoe.

 

[Tazza]

Sometimes its normal for this to happen with different weather. Say its cool when you un-hook your hoe, then it warms up and you try and attach it but the oil has expanded slightly due to the heat this will make it hard to attach, same with a sunny day. In theory when you remove an attachment no matter what, the oil will take up the same space in the hoses and cylinders even if the rams move due to internal leakage, only oil expansion can cause problems. Could it be as simple as the system has not released all the pressure when you un-hook? i know on my 743 its simple, you just shut down and jiggle the aux hydraulic control stick and it bleeds off the pressure.
Could it be that simple? i know you would get most of the pressure out as it won't un-hook with a lot of pressure behind it.

 

[kolo]

Sometimes its normal for this to happen with different weather. Say its cool when you un-hook your hoe, then it warms up and you try and attach it but the oil has expanded slightly due to the heat this will make it hard to attach, same with a sunny day. In theory when you remove an attachment no matter what, the oil will take up the same space in the hoses and cylinders even if the rams move due to internal leakage, only oil expansion can cause problems. Could it be as simple as the system has not released all the pressure when you un-hook? i know on my 743 its simple, you just shut down and jiggle the aux hydraulic control stick and it bleeds off the pressure.
Could it be that simple? i know you would get most of the pressure out as it won't un-hook with a lot of pressure behind it.

I understand about the expansion. Also my machine relieves in the same way, as you said you shut it down, power key and wiggle in both directions. Problem with mine persists no matter what. If I unhook the hoe and try to re hook it in the same minute it will pressure lock and will not go until I open the line with a wrench. I initially thought the same as you said, that over time one of the rams has moved or the sun heating it , but if I detach it I cannot even marry the lines together because the male coupler is pressure locked. I have gotten a copy of the owners manual and plan to go through the line routing and hook up step by step to see if something isn't improper.

 

[kolo]

I understand about the expansion. Also my machine relieves in the same way, as you said you shut it down, power key and wiggle in both directions. Problem with mine persists no matter what. If I unhook the hoe and try to re hook it in the same minute it will pressure lock and will not go until I open the line with a wrench. I initially thought the same as you said, that over time one of the rams has moved or the sun heating it , but if I detach it I cannot even marry the lines together because the male coupler is pressure locked. I have gotten a copy of the owners manual and plan to go through the line routing and hook up step by step to see if something isn't improper.

OK, I have checked the routing of the lines, inlet, outlet check valve and inline filter as well as confirmed supply and return on the New Holland 665. I can hook my grapple with no trouble. I can hook my drill with no trouble. The hoe is in the travel position that is to say that it has the manual safety bars holding the boom from moving and the outriggers are in the up position. Nothing is exerting force on any of the cylinders, the hoe is on the quick tach and has rigid locks to keep strains off the boom cylinders. some how , some way the male line on the hoe which is the return is locking up. I have tried removing them one at a time , 1 before the other and then the opposite. once un hooked the lines can nearly be put together and after 1 or 2 near completions the male becomes impossible to couple together util it is broken from the line with wrenches. Any one have any Idea? I'm trying to provide as much info as I can. I also understand that some Flat Faced couplers are made to hook under pressure. Should I need these? Thanks.

 

[mllud]

OK, I have checked the routing of the lines, inlet, outlet check valve and inline filter as well as confirmed supply and return on the New Holland 665. I can hook my grapple with no trouble. I can hook my drill with no trouble. The hoe is in the travel position that is to say that it has the manual safety bars holding the boom from moving and the outriggers are in the up position. Nothing is exerting force on any of the cylinders, the hoe is on the quick tach and has rigid locks to keep strains off the boom cylinders. some how , some way the male line on the hoe which is the return is locking up. I have tried removing them one at a time , 1 before the other and then the opposite. once un hooked the lines can nearly be put together and after 1 or 2 near completions the male becomes impossible to couple together util it is broken from the line with wrenches. Any one have any Idea? I'm trying to provide as much info as I can. I also understand that some Flat Faced couplers are made to hook under pressure. Should I need these? Thanks.

Flat faced couplers are becoming the standard. If you use rental attachments you will need them on your loader.
I dont know if they will cure your problem but using flat faced couplers would be a step forward. Mike

 

[Edu]

OK, I have checked the routing of the lines, inlet, outlet check valve and inline filter as well as confirmed supply and return on the New Holland 665. I can hook my grapple with no trouble. I can hook my drill with no trouble. The hoe is in the travel position that is to say that it has the manual safety bars holding the boom from moving and the outriggers are in the up position. Nothing is exerting force on any of the cylinders, the hoe is on the quick tach and has rigid locks to keep strains off the boom cylinders. some how , some way the male line on the hoe which is the return is locking up. I have tried removing them one at a time , 1 before the other and then the opposite. once un hooked the lines can nearly be put together and after 1 or 2 near completions the male becomes impossible to couple together util it is broken from the line with wrenches. Any one have any Idea? I'm trying to provide as much info as I can. I also understand that some Flat Faced couplers are made to hook under pressure. Should I need these? Thanks.

A greeting to all the members from Spain. I do not speak English good but I like it very much the NH skid steers,I know the "problem" of your hoe I want to help you. It proves this on having connect/dsconect the hoe. To connect: step 1: stop the engine, The auxiliary hydraulic lever of the skid steer must be connected. step2:Connect the hydraulic plugs (first the return plug) To disconnect: stop the engine,the auxiliary hydraulic lever of the skid steer must be connected. disconnect the hydraulic plugs.

 

[kolo]

A greeting to all the members from Spain. I do not speak English good but I like it very much the NH skid steers,I know the "problem" of your hoe I want to help you. It proves this on having connect/dsconect the hoe. To connect: step 1: stop the engine, The auxiliary hydraulic lever of the skid steer must be connected. step2:Connect the hydraulic plugs (first the return plug) To disconnect: stop the engine,the auxiliary hydraulic lever of the skid steer must be connected. disconnect the hydraulic plugs.

Problem solved by using a Parker Dual Valve flat face coupler specifically designed to hook under pressure. Special order for about $43 bucks. money well spent , now connect easily.