Jake Brakes?

Jcparmley · February 11, 2019, 10:27:30 AM

I have a MCI102c3 6v92 Mechanical with a HT740 Trans. How do I determine if I have Jake Brakes? I have the switch on the dash but I don't know how to verify if I have jake's.

TomC · February 11, 2019, 10:30:39 AM

First see if the engine has the tall valve covers. If it has the tall valve covers look for the small single wire coming out of each head going to the engine governor for the cut off switch. Finally, pull one of the valve covers to see if you have the Jake units mounted above the rocker arms. Most likely, you have an electrical problem. Good Luck, TomC

Jcparmley · March 04, 2019, 01:18:01 PM

I made a journey out into the snow drifts to look at my valve covers. I don't believe I have the tall covers and I didn't see a wire. However, I was only able to see the passenger side cover because the other side of the bus is covered by a snow drift. I included a couple of pics to verify. If I don't have jakes I wonder why I would have a switch at the date? How much would Jakes cost?

chessie4905 · March 04, 2019, 01:35:52 PM

There could have been jakes on previous engine that was replaced with this one. Someone started to get ready to install jakes, but didn't get past switch and wiring.

richard5933 · March 04, 2019, 02:49:20 PM

Quote from: chessie4905 on March 04, 2019, 01:35:52 PM
There could have been jakes on previous engine that was replaced with this one. Someone started to get ready to install jakes, but didn't get past switch and wiring.

Could be exactly that - our bus has a switch installed and is waiting for a trip to the shop for the Jake install. Someone buying the bus right now would be asking the same questions you're asking. Wiring was already in place in the OEM harness from the factory and only required adding a few parts (relay, CB, etc.), and I bet you have something in your harness similar if Jakes were a factory option.

Cost? I spent about $1500 to round up all the necessary parts. Maybe a little more when you include the relays, switch, paint for the new valve covers, etc. Still will have to purchase the rebuild kits for the Jakes so they can be installed fresh, and then there is the labor cost if you're not doing the work yourself. Most of the parts are available, but you may have to search a bit for them.

chessie4905 · March 04, 2019, 04:18:46 PM

Watch on Ebay. They come up all the time. Be patient. The buffer switch is costly. Plan on getting rebuild kits for the jake solenoids and youll need new fuel crossover lines and it is recommended to go with the new oring style which require different stands to be compatible with oring type, plus they need longer hold down bolts. Try to get a complete set with all the small items included. 92 and 71 series are different. I believe marked 71-92 is what to look for.

lvmci · March 04, 2019, 04:52:16 PM

Here's a picture of a Jacob unit...

luvrbus · March 04, 2019, 05:37:09 PM

Those are not Jake valve covers he has the non Jake Covers

Jcparmley · March 04, 2019, 06:42:12 PM

Richard, do you know of a good bus shop in Wisconsin?

Jcparmley · March 04, 2019, 06:51:44 PM

Would 8v92 silver series jakes fit a 6v92? Is there a model number for the jakes that I should search for?

richard5933 · March 04, 2019, 06:52:36 PM

Sent you a PM.

luvrbus · March 04, 2019, 07:00:34 PM

6v92 and 8v92 use the same except you have one master on each side with 2 slave on each bank and different valves covers

Jcparmley · March 04, 2019, 07:38:54 PM

Luvrbus, I just sent you a PM.

Quote from: luvrbus on March 04, 2019, 07:00:34 PM
6v92 and 8v92 use the same except you have one master on each side with 2 slave on each bank and different valves covers

Jcparmley · March 05, 2019, 10:46:53 AM

Does anyone have a pic of the tall valve covers?

Jcparmley · March 05, 2019, 11:33:54 AM

Do these look like the tall covers?

Quote from: luvrbus on March 04, 2019, 05:37:09 PM
Those are not Jake valve covers he has the non Jake Covers