Reviving an old Jake

[Ryan B]

Hey folks,

Just got myself a beautiful 1981 MC9 for my conversion There is a jake brake switch up front and the company thinks the brakes are still there but stopped being maintained quite some time ago. Needless to say they don't engage at all. Anybody have an idea where I would start diagnosing them? Though I guess my first step should be checking to make sure they're actually still on the block...

Cheers!

[luvrbus]

That is where I would start

[Utahclaimjumper]

Its as simple as removing the valve covers.>>>D ( And you only need to do the easiest one)
(The "company" may have removed and sold them, they bring big money used)

[robertglines1]

ck the switch.  see if it has continuity.

[sdc53]

See if you have power to one side of the buffer switch when the dash switch is turned on.  Of course this is after you pull the valve covers to see if they are still there.  Probably an electrical problem.

[luvrbus]

If they are there it will be a electrical or oil problem for sure only the 2 things it can be fwiw like anything they wear out and need rebuilding new control valves,o-rings and springs a kit cost around 125 bucks from a aftermarket supplier lot of buses have the switch with no Jakes is that a 8v71 engine ?