Series 60 12.7 Jake Brake

Jcparmley · January 09, 2021, 03:13:20 PM

Hello

I have a MCI 102dl3 with a Detroit Series 60 12.7. I am looking for Jake Brakes. I was told that I need Jakes 790B for my engine. However, they are very hard to find. I continue to see 765A, 797B, even 790A. My question is, will any of these other Jakes for a 12.7 work?

luvrbus · January 09, 2021, 04:28:07 PM

Bus engines used the 760b,765,765A,770 and 790 only difference is the bus model Jakes are less aggressive than the 12.7 truck models and some housing cover more valves ? are you installing a 1/2 set or raising the floor for a full set on your DL

Jcparmley · January 09, 2021, 08:09:15 PM

I'm planing on installing a full set and raising the floor for the taller valve covers.

Quote from: luvrbus on January 09, 2021, 04:28:07 PM
Bus engines used the 760b,765,765A,770 and 790 only difference is the bus model Jakes are less aggressive than the 12.7 truck models and some housing cover more valves ? are you installing a 1/2 set or raising the floor for a full set on your DL

Jcparmley · January 11, 2021, 09:25:02 AM

OK, I just found the correct Jake Heads. It was not easy to find. Now I need to find the bolts, tall valve covers, and harness. Question, is there only one type of harness or are the wiring harnesses different for each type of Jake? Also, would any series 60 12.7 two piece valve cover work or are they specific to a particular Jake model? Thanks for the help!

Jcparmley · January 11, 2021, 03:09:47 PM

One more question. The Jake heads I purchased are 12 volt for the solenoids. Can I make that work or will I need to purchase the 24 volt solenoids?

richard5933 · January 11, 2021, 03:45:45 PM

Are you going to use the factory harness & power supply for the Jakes or running your own wires?

If your factory harness already has wiring for the Jakes, double check to see if it's 12v or 24v. Not sure about MCI but on my GM I'm surprised sometimes and find 12v devices I expected to be 24v.

If you're running your own wiring, then if you have a 12v source to tap into in the chassis system it seems like you could run with that. Unless someone knows a reason why not.

luvrbus · January 11, 2021, 05:12:43 PM

You are going to need 24v and it going to take some programing on the engine and transmission have Allison program the transmission where you have no gear drop droping from 6th to 4th sucks , you can wire direct with 12v but not a good idea with your drive train

Jcparmley · January 11, 2021, 05:41:09 PM

Clifford

Do you know if my bus already has the harness under the valve cover or do I have to purchase one? Also, can any tall 12.7 valve cover work, or is it Jake model specific? Thanks for all the help.

Quote from: luvrbus on January 11, 2021, 05:12:43 PM
You are going to need 24v and it going to take some programing on the engine and transmission have Allison program the transmission where you have no gear drop droping from 6th to 4th sucks , you can wire direct with 12v but not a good idea with your drive train

Jcparmley · January 11, 2021, 05:48:45 PM

I'm hoping the factory harness is already in my bus. Then I can install the Jakes and have the computers programmed.

I will check the voltage before I order more parts.

Quote from: richard5933 on January 11, 2021, 03:45:45 PM
Are you going to use the factory harness & power supply for the Jakes or running your own wires?

If your factory harness already has wiring for the Jakes, double check to see if it's 12v or 24v. Not sure about MCI but on my GM I'm surprised sometimes and find 12v devices I expected to be 24v.

If you're running your own wiring, then if you have a 12v source to tap into in the chassis system it seems like you could run with that. Unless someone knows a reason why not.

6805eagleguy · January 11, 2021, 06:02:33 PM

Jc there are 2 different tall covers that I know of, 2 piece like mine in the first pic and one piece like second pic not sure the pros or cons of each

luvrbus · January 11, 2021, 06:33:57 PM

You should be able to find a taller riser and use the same valve covers,I doubt you will have a harness, you may get lucky though

ktmossman · January 12, 2021, 06:32:47 AM

If you call MCI with the VIN, they can probably tell you if the wiring harness is equipped.

Jcparmley · January 12, 2021, 04:34:10 PM

Today I spent a couple hours trying to find some history on my Series 60 Reliabilt engine. I called multiple certified Detroit shops and gave them my engine number and no one seems to be able to pull up any info, history, specs, etc. Does anyone on this forum have a contact that can lookup the data on a Detroit Relibilt engine?

Jcparmley · January 24, 2021, 08:34:31 PM

It looks like my valve covers are the two piece version. There's not much room for taller ones. I found a spacer on eBay but I am not sure it's the correct height for jakes. Here's a pic of mine. Does anyone have pictures of their series 60 with jakes valve covers so I can compare?

6805eagleguy · January 25, 2021, 07:27:22 AM

Jc you need a taller top piece I already posted this pic but here it is again

As you can see my spacer is the same but it's the top cover that's taller