Jake

[mikke60]

I have a 2 speed jake on my 5a with an 871.was working fine las t season. First trip out today and it seems it is not working. Any quick fixes I should look for before I do a thorough check.? 

Thanks ,mike

[bevans6]

When you turn on the switch, make you are getting power to the common terminal on the buffer switch.  If the engine is off you can manually put the governor in No Fuel with the engine stop lever, and you should observe the buffer switch working and sending power to the solenoids.  If you are running the engine with the jakes turned on, you should be able to see the power switch on to the solenoids if you rev up high (like 1500 - 1800 rpm and suddenly close the speed control lever.  When the engine goes on over-run, the governor goes to No Fuel and the buffer switch should close and send power to the solenoids turning them on.  You should hear the rattle as the jakes decelerate the engine and it might stall, if they are working.

If you have power and no jakes, then time for a more serious look under the valve covers.  You can measure the resistance of the solenoids, should be a couple of ohms.  Dead open or dead short is bad.  If the switch is on and no power, then electrical troubleshooting 101 - start at one end and work towards the other!  I would start at the dash switch, I had one go bad.  Don't forget the clutch switch if you have a 4 speed.  You might just need to go down a long hill with them turned on, sometimes I think they can be lazy if they haven't been used for a while, and you do need around 30 psi oil pressure to make them work, as I understand it.

Brian