Jake brakes problems

[rip]

I am having an electrical problems with mt jake brakes on my 85 8v92. My jakes were working fine however going down the road they go off and on,mostly off.Once and a while the light for the jake comes on for a second then goes off.
  I am currently in Post Falls Id. and heading towards Washington then down the coast.Does anyone   have any suggestions where I can get it fixed.I checked and found I have power going back to the switch on the engine.
   Don

[opus]

I cant really make a suggestion but if you need it fixed quick, I suggest you look near Spokane.  There is nothing much to the west of there for quite a while.

[luvrbus]

Sounds like the buffer switch Hillsboro Diesel not far from Portland will fix you up Butch has been at it a long time and won't gouge 503-640-9464 if only a adjustment that's all one pays for and he knows the 2 strokes   

[Lin]

What gear is this happening in and what transmission?  If you have and automatic and are in first or second, it is because the transmission is dropping out of lockup. The Jakes will not do any good in those gears.  Further, even though you are going downhill, the transmission oil will be heating up since the braking is being done by the torque converter.

I had this issue before modifications to force lockup in low gears.

[tomhamrick]

I was having problems with the Jakes on my 8V92 when I bought this coach. Took off the valve covers and found that almost all the electrical spade connectors inside were loose and some were hanging loose.  Had to squeeze them with pliers and slide them back on the connector. Also had one master that everytime I touched the solenoid it would activate. After scratching my head for a while I found that the ground strap on the side of the solenoid had come loose and I had to solder it back. All is working well at the moment.

[sdc53]

Just went thru a similar issue, diagnosed with assistance from the guys at Hillsboro diesel.  My jakes were flaky, sometimes wouldn't work - other times would work well.  I thought it was the buffer switch, I had them replace that and it didn't fix the problem.

This was the fix for me: Use an ohmmeter and measure the resistance of the wires that go to each head separately - measure between the wire and ground.  You need to disconnect them from the buffer switch to do this.  I found the inner head shorted to ground.  That was causing both sides not to work properly.  Of course that was the least convenient side to get to, so I was able to disconnect that side and run on half jakes until I had time to pull the turbo and valve cover to investigate.  One of the coils was shorted internally.. again diagnosed with the ohmmeter.  Replaced the coil myself, and all is well again.

It could be any number of things, a short, an open, in the wire, a connector, or coil. The ohmmeter is your friend to find it.

If you pull a coil, there may be a small o-ring at the tip of it.  Make sure you know where it went - mine stayed in the hole.  I had to use a mirror and flashlight to see it.

Scott
'69 4107
Gladstone, OR

[luvrbus]

It's all how the things are wired he says he has a electrical problem I assuming when he has power they work, on buses one never knows how they are wired so many different ways to wire one besides the dash and buffer switch he may not even have a buffer switch who knows  

He can by pass the buffer and check that part if they work with the buffer bypassed using only the dash switch then it is the buffer switch I never saw both sides fail at one time when they had power

 If he has the Micro type switch like is used on the fast idle type they have a diode that will go bad a .60 cent part repair job