JDcrawlers Messageboard

I re-read the parts and service manual, and they refer to the pressure relief as "adjustable". Anyone know how it's adjusted?

I live in the boondocks, and a real JD dealership is 200 miles away. It would cost a couple hundred just to get it there. For my use, the slow hydraulics are more of an inconvenience. To my engineering mind, flow and pressure are pretty tightly connected. If my pressure relief is leaking or maladjus...

It's not quite that simple. The mechanic replaced the steering clutches, the brake bands, one of the drums, and replaced the pins and bushings on the 6-way, so the hydraulics were open for a few weeks. The tipoff that he wasn't literate enough to read a manual is that the float valve "somehow" came ...

My JD450 has "slow" hydraulics, and I'd like to figure out if it's the pump or the relief valve inside the 6-way. I figure the best way to isolate the problem is to put a Tee, gauge, and valve (on the downstream side of the tee) on the inlet to the valve and see how the pressure responds to the valv...

My factory parts manual has a page dedicated to each serial number generation, so it wasn't much of a catch

Unfortunately, just my desktop PC, taking everything apart and probing the problem fixed it. I did find a few more puzzles during the search though: 1) The bulkhead connector between the instrument panel and the engine compartment has ten wires on the engine side but only eight on the rear side. The...

My manual shows your configuration was on machines up to 354074. Later units had a spin-on filter and a sender for an idiot light. I guess I'll take the six-way relief apart and see if all the parts are there...wish the weather was a little warmer!

I'm unclear on a couple of the details. 1) Is there a filter "in the tank" that isn't described in my manual? I have a spin-on filter on the top of the tank that receives the return oil from the six-way valve. It was my first suspect and has been replaced. 2) Is there an adjustable pressure relief s...

I've decided the hydraulic action is actually a lot slower than it was before my recent service. During that service, the brakes/clutches were replaced, so all the lines were open for a few months (don't hire a private shop!). My fuel line ended up with a blockage, either from stirring the tank or a...

My start circuit isn't working right now. I can start it by jumping the solenoid, so I assumed it was the neutral safety switch, which was recently repaired by a shop. The machine is "on call" for driveway grading right now, so I hesitate to take it to too far apart. My 450C manual (for SN 355844) s...

I had already looked at the Surplus Center alternatives. Thought I'd wait until I get the thing out and make sure there's not a pinched line or obstruction. They have some lower cost units just under 2.0 cu in that might work, but without the fitting sizes, etc. it's hard to shop seriously. There ar...

I don't think the hydraulic return filter can offer much resistance, since it's plumbed in rubber hose from the six-way spools. If there's a filter "inside" the tank, I don't know about it.

My manual says it should be a 15gpm gear pump. It's not leaking or making any noise you can hear over the engine. Is there a way to test the volume/pressure? I just resolved a fuel line issue caused by debris in the tank, so maybe there's a blockage or crimped tube on the route from the pump to the ...

I need to rebuild or replace my hydraulic pump (works, but everything is very sluggish). Any one removed one of these things without removing the nose and radiator? I wish the JD Manual offered more detail than "remove pump"

In case someone else loses their detent bits, I was able to repair my old one once I understood the physics. Unfortunately, my education cost me a replacement detent. I just took a 1/8" diameter welding rod and bent it around an appropriate socket to create a 3/4" ID o-ring (slightly spiral due to o...