How to bleed hydraulics

Not sure what tractor you are working with, but a lot of these systems will bleed off on their own when you cycle them a few times. Extend all cylinders as far as they'll go, top off your fluid and then cycle it several times over. Check fluid with rams extended and fluid warm. You'll probably need to add.

might check LINKAGE ???  ... read here

steve(ill) wrote: <span style="color: rgb0, 0, 36; : rgb254, 252, 212;">Was about 1000psi going up, hit 2000-2100 at peak. Then quickly dropped to 1000.</span> I think this is the D15 tractor.... You should have around 3200 psi i think. That is what the B -C- WD pumps put out.. HIGH PRESSURE, LOW FLOW... I "THINK" the D15 is similar.....Your guage should be working right.. but you could take the hose off to the cylinder and put the gauge ON the valve and dead head it... Should hit the PEAK PSI as it goes over relief. <span style="color: rgb0, 0, 36; : rgb254, 252, 212;"> </span> <span style="color: rgb0, 0, 36; : rgb254, 252, 212;"> </span>

Dang, that blue text is next to impossible to read on a phone! Gotta hit quote just to make it easier!

Apologies for not putting all the info in.

It is a D15 Series 1.

I am using the internal pump.

Trip bucket loader taking fluid from the line going into the remote block on top of the lift arms under the seat.

Tested the pressure using a gauge plugged into the remote.

The low lift power on the loader is what keyed me into the issue.

The tractor hydraulics to to a selector valve, out of the valve into the remote. The loader is hooked to the selector valve.

I'm about 99% sure the lift/lower is adjusted right in the center. However, using the detents is slow up or slow down. In order up get full speed I need to go passed the detents. This seems to jive with how the manual says it should be. But I would feel more confident if the "swing" between the two was shorter.

I didn't think about adjusting the lever to check pressure. But in my mind that would only effect speed/flow, not pressure.

On the older D-series, the "HOLD" range is quite wide. There isn't a "detent" like a WD/WD45. If you release the lever anywhere in the middle of the range, it is automatically in HOLD. To lower (depending on how you adjusted the lowering screw) you have to go below horizontal in the lower window. Fully RAISE should be when locked in the upper window.

Sounds like a tired pump as the max pressure should hit over 3,000 psi like 3400-3700 psi top spec. Nothing can be done externally and if it lifts what you want it to lift, keep using it as-is.

Are the hydraulics quiet when you see maximum pressure or is the system squealing loudly? Seen many a relief valve spring break from fatigue and the pump be fine after this is replaced and system calibrated properly. Got an Acura MDX in the shop now brought in after the dealer said pump was bad. Gauges prove otherwise and the steering rack is defective. 

Codger wrote: Are the hydraulics quiet when you see maximum pressure or is the system squealing loudly? Seen many a relief valve spring break from fatigue and the pump be fine after this is replaced and system calibrated properly. Got an Acura MDX in the shop now brought in after the dealer said pump was bad. Gauges prove otherwise and the steering rack is defective.  Water coming out is not good any way it's looked at and you probably have a worn out pump but still worth checking over.

That "rattling" is cavitation of the fluid. Change this first before any effective troubleshooting can take place.

Forgot to thank you, Doc.

It'll last me this winter. But if she gets a break this summer I'll take it apart and put it back together and see if that helps.

Thanks for sharing your knowledge!

Generally, springs and balls and Orings and a couple of gaskets are all that is needed and they ARE available from AGCO.