4-150 hydraulics

Running out of ideas again.

Beginning to wonder if I can just stuff a spacer in there to prevent the unloader valve from opening. That might get me hydraulics, but it might get harder to start (oh well, small price to pay since this is my one tractor that will pull the v-ripper.)

Dan

The Unloader valve has been mentioned and that is the first place to check. The hose that it returns oil through is at the top of the control valve and is held on with a hose clamp. Remove the hose from the elbow and put a short length of hose on and run it into a bucket. Unhook the wire to the fuel solenoid so that the engine will not start. Have some one crank the engine and see what kind of flow you get from the hose into the bucket, it should be a large quanity. If it is, reconnect the wire and start the engine. As soon as the engine starts the flow of oil should reduce greatly, this is when the unloader valve closes. The specification for the flow while the engine is running is 200 ml/minute maximum, a 20 oz pop bottle is about 600 ml, that should give you an idea of how much leakage is allowed. If you are getting more flow than that the unloader is not closing. Did you pull the unloader valve and it's seat out when you were replacing o-rings?

That is the first thing to check, if the unloader is working we'll go onto the next check. WB.

As for hearing that click... Sometimes it happens, sometimes it doesn't. PTO spins freely for the first 5 seconds after startup, but after that it stops and responds to the controls. Checking brakes just now (I never use brakes, many of our tractors don't have good brakes) it pulled hard to the left once (tried to articulate the tractor), second time nothing. I went out and specifically listened for that click this time, didn't hear a thing. Can't speak for the 3-point, the arms were removed long ago. Lever is stuck in the cab, cable is gone.

Engine RPM cannot be determined, tractor tach was broken when the tractor was delivered and hasn't been fixed. During the direct-pump test, throttle was near the bottom of the range (just fast enough to run smoothly.) The pressure did not appear to increase with the throttle.

When we reconnected the valves and used the remotes, the cylinder showed no movement through the full throttle range.

We have not yet put the pressure gauge on the power-steering line; we aren't sure where we can get the proper fittings.

I am told that this tractor is equipped with mechanical brakes, not hydraulic ones. Our working belief is that this tractor's 4 hydraulic hoses at the hinge are for the oil cooler and power steering only (one pressure, one return each.) But, again, this may be inaccurate, I have no documentation for this tractor.