Case DH4B Trencher/Backhoe Won't Spin Trenching Chain

   / Case DH4B Trencher/Backhoe Won't Spin Trenching Chain
  • Thread Starter


Silver Member
Jul 21, 2018
Farmall 100, Allis Chalmers D14, International Super MTA, IH 560, Mahindra 4510, Gehl 4500, Clark CY45, JD 800, JD 60
Large update. I installed the new hydraulic pump, I plumbed the motor spool to the hydraulic motor, filled the system back up and SHE WORKS!!!!! The chain spins, the hydraulics do what they are supposed to do. I don't have the digging chain back on, but the drive chain works perfect.

I only have one other issue and the the front backfill blade, still does not work. I dug into the unit pretty far and I found that the steering pump and the backfill pump are the same. Both features take pressure from the same pump, one works, one doesn't. So, I think the spool is no good. Not really interested in tearing into the spool again. I am thinking that if I get the system nice and hot, I wonder if the spool will loosen up enough to do something. If not, I think I will have to swap it out.

I also had a terrible thing happen upon the first start up after a couple weeks of sitting. I started it up, ran for about 10 seconds and I heard a loud ping come from the front of the engine and I saw the upper radiator support bolt fell out of it's hole and the fan hit the bolt, making a tiny hole in the radiator. Over 4 hours of sitting, it made a puddle the size of a silver dollar. I am thinking that I best off putting some stop leak in it, use it for now and look for a rad. There is a shop not too far from me, but I just got this thing together and I would like to run it for a while and then take the radiator out in the late fall once the machine is put away for the winter.