Jeremy Rowland wrote:ididntdoit73 wrote:Hi,
About this Priestman excavator there is a pedal on the floor in the cab am i right that its the pedal for the pecker? As its piped up for one.
Thanks.
I think Fred 'Fowler man' may be best able to answer that question?
Jeremy
Hi,
If the pecker circuit was original Priestman fitted it would have been opperated by a button in the top of the right hand control lever,
The machine could easily have been retro fitted with a pedal control, there should be an isolator switch on the pannel somewhere, if you find it and switch it on you should see the pecker pipes pulse when you opperate the control either way.
Some of the earlier priestmans had a straight line travel pedal though in the "Two" series this feature was usualy opperated by a button on top of the travel lever. This was to allow the opperator to have full power to both tracks when using the front end equipment for debogging the machine.
You said in an earlier post that the machine was slow and lacked power, This is not typical.
Priestmans used their three pump system which gave full flow from the three pumps for maximum speed under light load. When digging and the average pressure in the system increased to 1,900 p.s.i., the output of the third pump was dumped, effectively slowing and gearing down the hydraulics. As soon as the bucket came out of the dig the pressure drop would bring the third pump back in and return to maximum flow and speed. This system worked very well.
The problems you discribe could be caused by any number of things. Perhaps the servo pressure, (350 p.s.i.), is low and not fully opperating the spools in the valve blocks. perhaps the demand valve is not cutting the third pump in, pressures may be down, (M.L.R.V. 3,000 p.s.i), (S.L.R.V. 3200 p.s.i), filters may need changing or maybe the pumps have had their day??