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RetDA · (This post was last modified: 09-22-2013 08:19 by RetDA.)

(09-22-2013 00:23)davidbrady Wrote: Tommy,

There is a Webster Relief Valve in your hydraulic circuit. When neither the power steering nor the hydraulic fan is calling for pressure the relief valve redirects fluid back to the reservoir. I'd look closely at this valve. If it's failing to open pressures could build to excessive and damaging levels. Here's a schematic of your system. In the drawing item number 37 is the Webster Relief Valve:

My theory is that the pump worked fine as long as you were moving the steering wheel, when you stopped the pressure built and the shaft failed. When you stopped, the pressure had no where to go most likely due to a faulty Webster relief valve.

David, thanks - all of this is is slowly increasing my "mental database". FYI my last conversation with Glenn Rogers and John Hughes, they said in all their years, they have never seen such a failure as his. Being the 'vanguard' of a new bluebird issue sucks. But perhaps what I have experienced may save somebody else a lot of grief.

David - Just thinking, as the opposite of a failure of the relief valve resulting in extreme and damaging pressure; another hypothesis: could a failed or failing relief valve, result ln allowing the power steering to continue to work, but a greatly reduced flow of fluid to the fan motor?

That was exactly the "symptom" for the first operational test following the installation of the new pump and the new hydraulic fan motor. Power steering was "1 finger lock to lock", but only 750 RPMs at the fan.

Disconnected eveything, hoses, fittings checked for restrictions, reinstalled, third operational test indicated no pressure at pump, fan motor and no power steering. We went back to the hydraulic pump and removed it discovering the pump shaft separation.

David, please forgive my convoluted thinking, but maybe we missed the boat on this one - since there appears to be only one relief valve in the system, perhaps we should have started there in the analysis of the problem.