How hard is it to convert 1-stage Jakes to 2-stage Jakes?

[Mex-Busnut]

Dear Friends,

My current Jake system is just a simple ON/OFF toggle switch on the dash. And the Jakes appear to be working very well.

So how difficult or convenient is it to convert this to a two-stage system? Take into consideration I am based in central old Mexico, with tons of mountains all over.

Thanks in advance!

[luvrbus]

Does it have a buffer switch or is it hooked direct, takes it 4 wires from the front to the rear for a 2 stage Jake a waste of wire IMO  lol  


www.bernhardbus.com

good luck

[Mex-Busnut]

Thanks, mr. Luvrbus. What does a "buffer switch" look like and where is such a thingamajig located?

I will have to wait till Monday to check the switch and see if it has two or four wires.

[thomasinnv]

Buffer switch is attached to the governor. comes out the side with 2 wires attached. If you have 2 stage jakes your dash switch will have high and low and off. Single stage will just be on and off.

[TomC]

With a on/off single stage Jake, the wiring is relatively simple. You have power from the dash going through the on/off switch, then a single wire going all the way to the back to the buffer switch then the wire splits in two two to the two cylinder heads.  If you want a two stage, everything is the same up to the buffer switch, then you have to have another wire going back to the dash that feeds the high/low switch.  Then from the high/low switch will be two additional wires coming back to the engine-one wire for each head.  So instead of one wire, you'll have 4 wires like luvrbus said.  Good Luck, TomC

[bevans6]

Purely picking nits, as it were, the MCI way is to power the two stage jakes from the rear engine bay panel, to the buffer switch next, then up to the two way control switch, some fancy wiring up there, then two wires back to the heads.  That gets away with just two extra wires, total of three wires front to back.  The diagram is in the book with the stud assignments and everything.   I'd not worry about  it until you've driven it for a while and it starts to bug you.  As many gears as you have, if you are getting too much braking you can just shift up a gear and get a lesser effect since jakes are more effective at higher rpms.

I've always been curious - what kind of Doctor are you?

Brian

[busnut104]

I never thought that it was necessary for a 2 stage on a DD They do not hold back like the 4 strokes, this has been my experience. 

[Mex-Busnut]

Thanks to all for your input.

Since I already have my floor torn out, I m¡ght go ahead and run a dozen extra wires from the dash to the engine electrical panel to have as spares, and if I don't like the one-stage Jakes, I can go to two-stage.

I've always been curious - what kind of Doctor are you?

Brian

Doctor of Biblical Studies.

[TomC]

Busnut104- you haven't had your Jakes adjusted by Don Fairchild then.  With my bus weighing 31,000lbs, and pulling my car at 3,750lbs, I weigh in at 34,750lbs. Coming down the Grapevine going north on I-5, it is 5miles of 6% grade.  I am switching from 2 stage to single stage several times going down the hill.  If it were not for that, I would have to simply turn off the Jake periodically, which creates a bit of a rocking feeling in the bus.  With the Jakes adjusted properly, they are quite effective-actually more effective then the Jakes on my Caterpillar 3406B.  Good Luck, TomC

[lostagain]

Personally, I don't think you need 2 stage Jakes in a bus.

I had them in the D3, S60 and hardly ever used Low. Wouldn't miss that if it didn't have it.

Both my Courier 96 and my 5C have single stage Jakes, and that's all you need.

Going down a hill with them on, you just press the accel. pedal a little to turn them off. They only come on with your foot off the pedal at no fuel.

Good idea to install extra wires while your floor is up.

Just drive your bus with single stage Jakes for a while first, to see how they feel.

JC

[luvrbus]

Waste of wire Jakes depend on the gearing the low side on a bus with 3:73 or 3:36 rear gears and in 3rd or 4th on the transmission will do no good I don't care who adjusts it and Don Fairchild is a good friend just so many ways to adjust one, a 71 series you can get away more than on 92 series if you have the 71/92 housings  JMO  I tell Don to stop wasting wire lol but we do it our way we are all different it is almost imposable to stall a 2 stroke using Jake wired direct because of oil pressure not that way on a 4 stroke you can stall the engine with the Jakes  

good luck

[Bill B /bus]

V71 in a 4108. Set the Jakes up as two stage. Found a lot of downhills that one bank, first stage, would hold the speed nicely. Some hills. like the one on I 24, need all the Jake you can get. So my vote for a two stage Jake setup.

[luvrbus]

You have a 4 stroke Bill big difference in braking power compared to a 2 stroke

good luck