This is a bit of a long shot but I am hoping someone knows of something similar used on a machine - which would be cheaper. So I priced up a hydraulic pressure switch for the transmission system the other day for a tractor at home and the dealer price was close to 200 pounds (300 USD) - there's nothing fancy about it. ANyone who has had anything to do with the Case Maxxum 5100/5200 range will know this as the sensors in the shift manifold which detects off going and on coming pressure. This sensor has a 1/4 gas (NPT) thread, it is a normally closed switch up until 100 psi, after this it opens and is fully open at 120psi. The max. system pressure is about 300psi and has two wires off it to the harness. Does anyone know of something similar, maybe a firm that spe******es in them.
Is this the right one? http://www.ebay.co.uk/itm/410438A2-...254?pt=LH_DefaultDomain_0&hash=item35dca4b826 Should be easy to pick up a fixed or adjustable pressure switch, CAT for instance supplies a number of them. Any hydraulic supplier should have them also.
I'd reckon it would need to be a genuine Case one, for one reason - it doesn't apparently have a single pressure at which the switch status changes from N/O to N/C or vice versa, most pressure switches do, so there could be something "a bit different" about it. Note what the OP says - "it is a normally closed switch up until 100 psi, after this it opens and is fully open at 120psi". that's not like any normal pressure switch I'm familiar with, that basically opens at X +/- Y psi. I take from what was written to mean that it's a bit like a thermostat that starts opening at X degrees and is fully open by Y degrees. I may be wrong here, but all I have to go on is what the OP wrote.
Yep, part# would have been helpful
Ian, thanks for that, its the switch i was looking for - at a substantially reduced price.......I think our dealers in this country must have a heavy finger on the calculator.
Nige, Basically if there's 100psi or less in that powershift gallery then it sends a message to the module to that effect. When the gear is selected, pressure ramps up to 300psi, once it goes through the 120psi mark it opens the switch. So the 20psi threshold is the transition time. When changing from 1st to 2nd if the module reads pressure in both circuits (stuck switch or solenoid) then it won't allow the shift to complete, it stops the tractor and the warning light flashes twice to say that "off-going pressure was not detected". I hope I have explained it well enough. Its brother's tractor with this intermittent fault, I have swapped the switches around to see if the fault has moved but we haven't had a chance to get the tractor really cooking to recreate the fault......and know he would have coughed at the U.K. dealer price, but the e-bay one from Ian makes it a whole lot more palatable.