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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: silversport on August 09, 2021, 08:39:51 PM

Title: Fast idle cylinder/Jake buffer switch issue
Post by: silversport on August 09, 2021, 08:39:51 PM
Still chasing down oil leaks, today I discovered that the fast idle air cylinder that attaches to the governor housing was loose, to the point where the shaft & housing threads are worn away. I have Jake’s & air throttle, Jake still works, not the fast idle. It looks like I’ll need to try to get a helicore into the housing (if there is enough room). My Jakes are wired with the buffer switch on the fast idle and there is a switch on the air throttle, my Jacobs instruction manual shows nothing on a switch on the air throttle. I do not use the fast idle very often so eliminating that is an option. With all my research not sure if the buffer switch and switch on air throttle do the same thing. If so I have an option to seal the fast idle hole in the housing and just use the air throttle switch as the buffer switch, I spitballing here, any input would be welcome. I only activate  my Jakes when I want to slow down. DD 8V71
Title: Re: Fast idle cylinder/Jake buffer switch issue
Post by: richard5933 on August 10, 2021, 02:43:25 AM
Have you ever had both fast idle and jakes functional? Or has the fast idle never worked for you, only the jakes?

There is a particular piece of hardware that mounts the jakes in a way onto the fast idle cylinder which allows both to function. You setup looks to be a workaround for someone that didn't have it.

Any photos of the rest of the set up (fast idle cylinder, etc.)
Title: Re: Fast idle cylinder/Jake buffer switch issue
Post by: luvrbus on August 10, 2021, 07:33:59 AM
The screw in stem is for a buffer switch ,the switch is gone and your jakes are wired direct .you control the Jakes  OFF and ON right ?
Title: Re: Fast idle cylinder/Jake buffer switch issue
Post by: silversport on August 11, 2021, 09:45:06 AM
I am not sure on how the Jakes were wired, fast idle and Jakes did work (not sure if Jakes were working properly to begin with, now that I'm reading the instructions manual). They may have been working just on the on/off switch since I've owned the coach.
In all my reading of the manual (Detroit Diesel) it looks like the fast Idle was an option on the 71/92, so I think eliminating that switch and plugging that hole may be an option. Just not sure on the Jake buffer switch if the air switch on the throttle is/was a replacement for the buffer switch (that was not working?). I am spitball here, still looking into a helicore to replace all switches the right way.
Title: Re: Fast idle cylinder/Jake buffer switch issue
Post by: richard5933 on September 17, 2021, 03:40:07 PM
Here's what mine looks like. Hope this helps. The switch brackets are still out there if that's the problem.
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