rear arm will only work 1 lever at a time then waite to move again

[crew_cab]

the backhoe is slow when hot about 1/2 hr digging is it the pump or any info wold be grate the front end works as normal please help does anyone
have any ideas p

[Jeremy Rowland]

Hi Cath and welcome I'm no JCB expert but if the front end works fine when the machine is hot and has been working for a time but the backhoe fails to work correctly then I would think that the hydraulic oil pump is okay and the issue would possibly be more to do with the spool valve; I have a vague recollection that somebody else on here experienced the same problem so have a browse through the topics and see if you can find it, hopefully somebody on here will be able to offer you better advice.

Jeremy

[FOWLER MAN]

Hi, and welcome from me too.
Which model is your JCB
As Jeremy says, if the loader works properly the problem will not be with the pump.
There is only one main relief valve which controls both the loader and digger so you can eliminate that too.
Each service, (ram), except the stabiliser legs has its own service line relief valves which prevent overloading the system. A fault here would only affect one function so these are unlikely to be the problem.
It is difficult to be sure without pressure testing but I would suspect an internal leak in the excavator spool block. This could be an O ring or seal or even a crack.
Is there plenty of oil in the system and is the suction strainer clean . Is the pressure crossover tube which carries the oil from the loader valve to the digger valve block damaged or restricted in any way
Good luck.
Fred

[crew_cab]

Hi, and welcome from me too.
Which model is your JCB
As Jeremy says, if the loader works properly the problem will not be with the pump.
There is only one main relief valve which controls both the loader and digger so you can eliminate that too.
Each service, (ram), except the stabiliser legs has its own service line relief valves which prevent overloading the system. A fault here would only affect one function so these are unlikely to be the problem.
It is difficult to be sure without pressure testing but I would suspect an internal leak in the excavator spool block. This could be an O ring or seal or even a crack.
Is there plenty of oil in the system and is the suction strainer clean . Is the pressure crossover tube which carries the oil from the loader valve to the digger valve block damaged or restricted in any way
Good luck.
Fred

thanks will get someone to look i havent changed fillter or anything yet didnt want to waste oil if needed a pump its a jcb3c3 powertrain someone said theres a fillter on other side of the big one so as you can see not sure what to do would a s/h pump be a good investment does anyone know what one would cost thanks

[crew_cab]

how many fillters are there on a jcb 3c mk3 powertrain oil tank looks full not that clean looks a bit milky
it had a new pipe begining of the year one joint was cracked didnt loose much oil level didnt drop
is there any were i could get s/h pump at reasonable price or are they easy to put new seals in just dont know

[crew_cab]

forgot to ask but in thr cab theres the clamp lock on left
but whats the one on the right side do it also has a pedal on floor like a brake peddle?

[essexpete]

Have you tried the front end with some serious weight when hot? Regarding the pedal do you mean the small round one that sticks out through the floor? If that is what you mean that is the transmission dump or disconnect pedal and it should not be used as a clutch absolutely no feathering or slipping in or transmission damage will occur.

[crew_cab]

no when you turn and face the backhoeto work on left side is a leaver unlocks the clamps for side movement of backhoe but on the floor in the middle there is a long pedal( like a truck brake pedal) its where your feet are, there is also another lever the same as the clamp locks on your right never seen one before any ideas