52 8n No Visible Leaks, No lift

   / 52 8n No Visible Leaks, No lift #11  
Hyd_lift_leak_points.jpgI have a hard time believing that no one in 2 cities have a pressure gauge capable of 2000-4000 psi ( usually in pipe thread ), and then a simple pipe thread to orb adapter.

My TSC carries these on the wall. NApa too.


here is a marked up diagram based on the diagram in fo-4 service manual. A friend of mine and a few others here, from another board marked it up / made it. ( jmor ).
 
   / 52 8n No Visible Leaks, No lift #12  
ps.. port is 1/2"-20 ( sae -5 ) get that fitting in an ORS/ORB to something like 38 npt female, then screw in a cheap 3/8 npt gauge capable of at least 2000 psi.
 
   / 52 8n No Visible Leaks, No lift #13  
The first thing to do is remove the right hand cover with the dipstick.
Then with THE ENGINE OFF reach your hand in and feel the valve spool rocker on the front of the pump.
Now, actuate the lever up and down.
Is the spool moving freely in and out?
Is the draft control spring over tightened?
Also, the number one reason fo problems with 8N hydraulics are caused by folks pulling off the top assembly without a plan for setting it down. So things get bent.
The last one I went through was a mess of belt linkages.
I was a able to have a functioning unit for comparison.
After heating and bending linkage parts back into shape, the lift works perfect with no further problems.

Physically check that the valve is operating and that the draft control spring is adjusted properly.
That is step one and two.
 
   / 52 8n No Visible Leaks, No lift #14  
Harry, posts #2 asked about the valve movement, and post #4 confirmed it.

Still a possibility of crud in there though.
 
 
Top