ford 1700 hydraulic problems

[JC-jetro]

thanks for checking on me. you are a great help. i was ready to give up and take it to shop. i have done some of what you are talking about, but will go and recheck in the order you suggest. should have that done around mid morning.

on the plug on the left you have a spring and a ball check. Do make sure the take out and record the order so you can put it back just how you found them. good luck.

 

[mellowrose]

just wrote a long reply and it went to never never land. lets see if i can do it again, short version. did every thing you said, no lift. however there is some interesting points. when i took the pressure gage off there was some pressure and fluid came out. so its getting thru somewhere with air like there is an air leak. or maybe accumulated air in the system. also when i shot air into the bottom left hole looking from right wheel, seemed like it would pressurize the rear end then come back out when it quit.

 

[mellowrose]

seems like there should be a hydraulic flow diagram somewhere

 

[JC-jetro]

seems like there should be a hydraulic flow diagram somewhere

did you remove the guts out o teh pressure relief valve next to the hyd block?

 

[JC-jetro]

just wrote a long reply and it went to never never land. lets see if i can do it again, short version. did every thing you said, no lift. however there is some interesting points. when i took the pressure gage off there was some pressure and fluid came out. so its getting thru somewhere with air like there is an air leak. or maybe accumulated air in the system. also when i shot air into the bottom left hole looking from right wheel, seemed like it would pressurize the rear end then come back out when it quit.

also when i shot air into the bottom left hole looking from right wheel,

Where are you exactly talking about. Are you taking about the thru where the gauge is? if so that would basically pressurize the piston forcing it to lift up some. No air is compressible bit no hyd fluid. I had drawn the flow duagram many years ago on this site. let me see if I can dig it out.

 

[mellowrose]

DID NOT REMOVE THE GUTS TO THE PRESSURE RELIEF sorry thats in caps it was on. the plate that the aluminum block and pressure reliefe biggyback bolt to. on the other side of the plate is the control valve line up with one of the three holes. the left hole

 

[JC-jetro]

DID NOT REMOVE THE GUTS TO THE PRESSURE RELIEF sorry thats in caps it was on. the plate that the aluminum block and pressure reliefe biggyback bolt to. on the other side of the plate is the control valve line up with one of the three holes. the left hole

Ok. I have several pics of the pressure relive valve guts. I you remove the cap, and take out the spring and conical poppet valve Then if you put the cap back in and start the tractor then the pump will have flow but not much pressure. in that case if the spool is working ok and you have the lift lever all the way up then you should have good flow from where you installed the pressure gauge, again with not much pressure, we want to establish flow or lack there of. Attached I have a pdf of the spool valve, you see there is o-rings and seal, any # of them could be faulty. This would not be easy repair. I have never disassembled as I had never a need. again , if you are disciplined and disassemble, taking many pics slowly then should be able to replace o-ring and put things back together. doubt if you can find new one and if yu buy salvage at high $$$ doubt if they are any better than what you already have.

 

[mellowrose]

have taken the conical seat out and started tractor. nothing on gage. stopped tractor remove gage. started tractor. nothing coming out.

 

[mellowrose]

also the loader quit working. put conical seat back in. loader works again . no lift. seems to me there is nothing but feed throughs and passageways which have all been blown out, until you get to the control valve and relief valve assy in the rear end. there is nothing else to check. guess i will look into the control and relief valve assy tomorrow. am i missing anything.

 

[JC-jetro]

also the loader quit working. put conical seat back in. loader works again . no lift. seems to me there is nothing but feed throughs and passageways which have all been blown out, until you get to the control valve and relief valve assy in the rear end. there is nothing else to check. guess i will look into the control and relief valve assy tomorrow. am i missing anything.

Before you mess with the spool valve check the following. Look at the pic below.



The hole on the right side with the o-ring is your supply to lift piston. The hole in the middle is the rate of return drop, next to to it o the lift is the supply to top of piston. The very last one on the left opens up in diffy and that is the over pressure release to keep the seal from being damaged. Now you see the head is symmetrical and has two identical ports . If by mistake you installed the head 180 out then the hole does not match the casting on lift cover hence no pressure and flow to the 3 point.

Now look at the pic below. That hole should line up with the hole you see on the right of lift cover as you seat on operator seat. That is where oil from the lift cover casting goes to lift piston head.



do check it before you mess with the lift spool. That is not an easy work and I have never ad a need to dismantle it yet. you have arms, pivot point that moves a plate in an out and then it moves hyd valve in and out along with spool. if you have caliper, make measurement of how many turns the nut are tighten to put every thing back how you got them. Take bunch of pictures so y can put it back together. this might be a good learning opportunity.


Ps. obviously loader would have nt worked and like I said. we were looking at flow and wth the spring out pump can make any appreciable pressure.