6v92 and jakes in my 70 ton crane. There is no remnants of any kind of safety cut off between the throttle and the jakes. It has a air throttle in the lower where you drive the crane from. The jakes are just on a 3 way switch in the lower cab. Off, low and high. I'm super careful to stay off the throttle with it when the jakes are activated, but I've got a new guy working for me, who may be driving it some. I think it will be a pain to install feeler switches, but if I have to I have to . I had a thought to install a air activated brake light switch- like on a air brake treadle valve, and plumb it into my air throttle on the lower. Air pressure on the line, as soon as your get into the throttle, would cut the 12 volt to the jake switch. Just like when the air pressure makes the brake light come on. Any better ideas or solutions? I just don't want the new guy accidently into the throttle with the jakes on.
The Jakes on a 2 stroke Detroit are also activated by a switch on the governor buffer screw that will shut them down when the rpm and load is off. Your switch may need adjustment. Find a 92 series Jake manual online. Its not that hard to adjust, but I cant remember how to explain it. But I can do it.
https://www.jacobsvehiclesystems.com/files/support/docs-pdfs/003879.pdf Page 5 of this manual shows a jacobs buffer switch for the governor. I'll look tomorrow, but I don't think my governor box has anything like that. I imagine it just acts like a prox switch in addition to the buffer screw, and the gov. arm has to be all the way back to allow the jakes to come on, and as soon as the throttle would move the gov. arm the switch would open, disconnecting the power. Thanks rzucker, I'll see what I can dig up. I appreciate it.
Looks like I'm searching for a 01-22351 for a new part #, looks like around $90-100 online. Its not really a prox switch, looks like a actual push button that is on the end of the buffer screw.
That's the one, To adjust it, turn it in 'til it just starts to increase the idle speed, back it out 'til idle is just back to normal and lock it there. Oh, you want the engine good and warm so it's not trying to do the "cold oil lope". With a two Jake stage switch the incoming power to the switch will have to go through that buffer switch.