710 d has problem in hydrolics ax like main pump is destroking to soon no power in all hydrolics. did presure test found low presure in charge circuit on test port on main pump .have checked or replaced all that can cause low charge presure according to manual still low charge presure have found correct charge presure on test port on backhoe

The WOT ( Wide Open Throttle ) relay is controlled by the PCM, this is a relay that is powered by fuse #13 in the engine compartment fuse panel. 1st thing to check, this is the same for both the L & the NA 5.4L engine.

The next problem could be with the high speed fuel pump motor or the fuel pump relay . The SC 5.4L has 2 fuel pump motors in the fuel pump assembly. You should get a DTC if there is an issue here ( low fuel rail pressure, or a DTC specific to the high speed fuel pump ).

The other items to check, when you are in boost, Charge air cooler pump relay & fuse ( engine compartment fuse panel, fuse #106 ).

do you have a tune loaded ? ( chip installed with the edge pins or download via the DTC port ) ?

first thing I would do is test the pump itself even if no wear is found you could have a GPM loss.
So you need to do a flow test on it to find otu how much the loss is and check it to the specs of that hydrolic pump first.

FC IS FREON CHARGE, WHAT YOU ARE GETTING IS A HIGH PRESURE CUT OFF  FAILURE. THE LABEL PRESURE IS TEST PRESURE. THE RUN PRESURE ON LOW SIDE IN AC MODE IS ABOUT 65 AT 75 T0 80 DEGREES INSIDE AND ABOUT 200-300 HIGH SIDE AT 75 -85 OUTSIDE TEMP. IN HEAT THE LARGE COPPER LINE BECOMES HIGH SIDE HOT WHEN YOU FEEL IT. IF YOUR FREON IS LOW WILL WILL ALSO GET SHUTDOWN. YOU WILL NEED SET OF FREON GAGES AND CONTACT ME BACK

i think i would check the fuel presure regulator and the fuel presure if fuel presure low look at fuel filter if rail not holding presure then look at fuel presure reg and vac conection on it

do they work off air presure then or hydrolic if hydrolic u need to bleed the brake

has the charge been tested< these suffer from leaks, have the system leak tested and then repair and recharge.

you have a bad fuel pump or a bad ingtion coil and both can be tested, and they should of thrown a code if notthing you can be assured it's the fuel pump. and it can be tested. and ifthey read the soft codes they will know what happened.

Stopped up suction screen can cause this. Also pressure regulator.

go to google type in this:AX-90 TYPEWRITER USER MANUAL

if this occurs when the unit is in use for only hot water, there will be an internal leak in the secobndary heat exchanger, you will have to replace it. check first that the charging link has been removed when testing to ensure it is not passing.
if it happens when the heating is switched on then check the presure in the expansion vessel ( dump all presure from system and use a car foot pump with a gauge there should be 1 bar presure) that is the big red thing behind the pump, if water comes out of the test valve on the front of it when you try to test it or it wont hold the presure you will have to replace it (a nasty job you have to strip half the boiler) if you can pump it up make sure you release the presure in the system as you pump it or you will get a false reading