Author Topic: Jake Brake switchology  (Read 6138 times)

Mike Stuart

  • Guest
Jake Brake switchology
« on: September 18, 2017, 01:51:25 PM »
My Jake Brake switching protocol has changed on my 02 Marquis.
When I first bought the coach 2 years ago, the switch operated:
Rear position: Off
Center position: Low braking
Forward position: High braking

For some unknown reason (not connected to anything else changing or done to the coach), the switchology changed to:
Rear position: Low braking
Center position: Off
Forward position: High braking
Also, when this changed, the "Engine Braking" light comes on when the brakes are depressed with the switch in what is now the Off position, the center position.  The Jake Brake works and is effective with the exception of the change in switchology and the indicator light illuminating when the brakes are depressed without engine braking selected.

I have had a couple of dealers look at this and they don't really have an answer on how to correct.  One shop has suggested replacing the engine electronic control which I have not done, but nobody has any idea what caused the change.  To be sure, the Jake Brake works fine, just with a changed protocol.

I'm wondering if anybody has seen this problem or might have an idea on what caused the change.


Dave Atherton

  • BAC Member
  • *
  • Posts: 1015
  • Thanked: 877 times
Re: Jake Brake switchology
« Reply #1 on: September 18, 2017, 02:28:49 PM »
Mike, sounds like your problem can be in three places. First, connection atactuator solenoid
Under valve cover loose. Dirty connection where Jake brake wires leave valve cover at connection
For wire loom. Third dirty or loose pin on ECM or loose connector connection wire loom bolt is
Loosen up. I assume your service people checked out the switch on dash and found it good.
I can provide the wiring diagrams for your Jake brake if are trying to repair yourself, what would
help in providing technical support Engine Serial Number from what I can see so far that you
have a C-12 505 hp.   Dave Atherton Retired Cat Mechanic

steve zannella

  • Guest
Re: Jake Brake switchology
« Reply #2 on: September 19, 2017, 12:29:43 AM »
Mike
For what its worth my 04 marquis jake switch works the same as yours front depressed 6 cyl on middle position off back position 3 cyl. Dash light come on when jake switch is engaged and second light comes on jake valves are engaged.

Steve

mike groves

  • Guest
Re: Jake Brake switchology
« Reply #3 on: September 19, 2017, 03:02:48 PM »
My '99 Marquis also works as yours now does and everything I've heard/read says this is the "normal" operation and middle is "OFF", back is low, front is high braking.

I am surprised that dealers haven't said so as well.

Recently, mine failed to turn on the braking but I simply reset the wires on the relays and it now functions again.  I have since replaced both relays having to do with Cruise/Retard in the basement cabinet under the driver seat.   

If anything perhaps someone has moved those wires on those relays thinking they were doing something else.  My schematic doesn't exactly match the relay configuration.

Mike

Mike Stuart

  • Guest
Re: Jake Brake switchology
« Reply #4 on: September 20, 2017, 03:13:43 PM »
Thanks to all that have posted on this.

Joel Weiss

  • Guest
Re: Jake Brake switchology
« Reply #5 on: September 22, 2017, 05:26:24 AM »
After 55,000 miles of driving I'm pretty sure that on mine, rear position is full  Jake, forward is low (3 cylinder) and center is neutral.  That's what the previous owner told me and is how it seems to work when coming down steep hills.

David T. Richelderfer

  • David, Leslie, Jasper, & JoJo
  • BAC Member
  • *
  • Posts: 1676
  • Thanked: 497 times
  • OSU, Class of 1971, RVing nearly 50 years
Re: Jake Brake switchology
« Reply #6 on: September 22, 2017, 12:20:24 PM »
Our Jake works with Jake on low when the switch is depressed to the rear, Jake off when the switch is level, and Jake on high when the switch is depressed to the front.  When the switch is depressed to either low or high, there is a yellow light on in the dash.  With the Jake switch on either low or high, then the Jake activates to low when the vehicle speed is 2 1/2 mph over the cruise control setting and a second yellow light comes on at the dash.  If the vehicle speed increases to about 4 or 5 mph over the cruise control setting and the Jake switch is on high, then the Jake goes to high.  When cruise control is off, then the Jake always activates to whatever the switch is set to, low or high, at any speed.

On the SilverLeaf screen when the Jake is activated to low, then the "J" is green; when activated to high, then the "J" is red.  Interestingly, at 2 1/2 mph over the cruise control setting and the Jake activated, then the "J" is green.  But at about 3 or 4 mph over, then the "J" changes to yellow.  At about 4 or 5 mph over, then the "J" changes to red.  Actually, I don't recall at this moment if the Jake initially changes to high with the yellow "J" or the red "J".

One may wonder how I know all this detail because this stuff only happens when starting down a steeper hill.  lol  With the Jake switch on high I usually touch the brakes when the Jake comes on when going down a steeper hill to insure the cruise control setting is off and the Jake is always on high.  And I had our Jake programming changed to not cause a transmission gear change when it activates - a much better setting!
« Last Edit: September 22, 2017, 11:11:15 PM by David T. Richelderfer »
2004 Beaver Marquis Sapphire

I had a dream... then I lived it!

Mike Stuart

  • Guest
Re: Jake Brake switchology
« Reply #7 on: September 22, 2017, 11:11:05 PM »
Thanks David,
I guess my switchology (while changed) follows yours and others.  The only issue I have is that the Eng Brake light comes on each time the brake is pressed even without the Jake Brake selected. 

Your coach also has different operation as mine won't permit selection of the Jake Brake with the Cruise Control on; it trips the cruise control off and this is described as normal in the manual.  Also, your Silverlake system has a JB indication; mine does not.  I suspect these changes are the result of your 04 vs. my 02.


Dave Atherton

  • BAC Member
  • *
  • Posts: 1015
  • Thanked: 877 times
Re: Jake Brake switchology
« Reply #8 on: September 23, 2017, 04:24:34 AM »
Gentleman, reading all the above post about what go where on the Jake Brake operation
on your Caterpillar engine. Maybe I can provide some technical information on this subject
off Caterpillar Service Information system the way Caterpillar shipped the engine at build.
Will relate correct information than will post hard copy technical information on Ask Dave
Technical Information.  The way engine retarder switchs are moved to the following positions.
OFF - LOW - MEDIUM - HIGH, if the status of the switches does not correspond to the position
of the switches, refer to troubleshooting. Retarder ( Compression Brake ) Solenoid circuit test.
Dave Atherton Retired Cat Mechanic

Pat Long

  • Guest
Re: Jake Brake switchology
« Reply #9 on: September 23, 2017, 04:39:37 AM »
Dave,   Are you implying that All Cat's that have a Jake, have 3 stage activation and not 2?  My 2000 Marquis has a 2 stage as stated in other post.  My 2006 T800 KW Heavy Haul tractor with C15 has as you have stated, 3 stage Jake activated on the Smart Wheel.  My coach is on left side control panel, back low, middle off, forward is high. 

Dave Atherton

  • BAC Member
  • *
  • Posts: 1015
  • Thanked: 877 times
Re: Jake Brake switchology
« Reply #10 on: September 23, 2017, 05:00:48 AM »
Pat, the engine compression brake is used only in Caterpillar Wet sleeve engines ( C-10 and up )
Cat C-9 and down have what is called a exhaust brake. Going back to the position of 1 & 2 and
position 1 & 2 & 3 will depend on your horse power and Serial Number of your engine. What is
Going to be posted on Ask Dave will show 3 positions on switches, starting with engine Serial number
prefix 2KS. Dave Atherton Retired Cat Mechanic

Dave Atherton

  • BAC Member
  • *
  • Posts: 1015
  • Thanked: 877 times
Re: Jake Brake switchology
« Reply #11 on: September 23, 2017, 03:22:18 PM »
Operating the Auxiliary Engine Brake. The auxiliary engine brakeis controlled by a switch on the dashboard. Before starting the engine, ensure that the switch is in in the off position. After the
Engine has reached normal operating temperature, turn the switch to the on position. The switch may stay in the on position durning engine operation. The auxiliary engine brake will only activate when no fuel is supplied to the engine. The auxiliary engine brake will help slow the vehicle when no pressure is
applied to the throttle. The auxiliary engine brake can be programmed to one of three modes.
COAST, LATCH, MANUAL. The coast mode and latch mode required the cruise control switch to be in the on position. The coast mode and latch mode do not require the cruise control to be active. In
the coast mode or the latch mode, the auxiliary engine brake is activated by the service brake, using
the service brakewill deactivate the cruise control. However the service brake does not turn the cruise control off.  In the manual mode, it is not nessary to depress the service brake in order to activate
the engine brake. If the cruise control On/Off switch is in the off position, the auxiliary engine brake will activate reguardless of the service brake. Will post this technical information on Ask Dave.
Dave Atherton Retired Cat Mechanic

Lee Welbanks

  • Guest
Re: Jake Brake switchology
« Reply #12 on: September 24, 2017, 11:05:45 PM »
Dave, With my PT it is set to manual and I also had a shop up in Wash reprogram the Allison 4000 trans not to shift down everytime the engine brake comes on.

Pat Long

  • Guest
Re: Jake Brake switchology
« Reply #13 on: September 26, 2017, 04:10:58 AM »
Pat, the engine compression brake is used only in Caterpillar Wet sleeve engines ( C-10 and up )
Cat C-9 and down have what is called a exhaust brake. Going back to the position of 1 & 2 and
position 1 & 2 & 3 will depend on your horse power and Serial Number of your engine. What is
Going to be posted on Ask Dave will show 3 positions on switches, starting with engine Serial number
prefix 2KS. Dave Atherton Retired Cat Mechanic

Dave,   I have used a Jake Brake for over 40 years.   My understanding in previous post was that all of the switching being questioned was no 2 stages but they should be 3 stages.  My First was on a small cam Cummins, then  Drip Droits, and most recently C15 Cat.  When used in conjunction with the Cat retarder the 2 systems Will NEVER Be Outdated.  I could go down ANY 6 % grade with 130,000 lbs and NEVER touch the brakes, just need to watch the retarder oil temp.   To bad Cat is out of the Class 8 Truck Market.  You have mentioned 2KS in you last post and that is my serial number lineup.  Will watch for more info

Lee Welbanks

  • Guest
Re: Jake Brake switchology
« Reply #14 on: September 26, 2017, 05:24:22 AM »
Pat, Funny I'll bet not many in here know what a Cat retarder is, ran one back in the day in a Pete with a cranked up 1693TA, last one I had was a 3406B that had engine brake with the 3 stages. It works as 2 cyl, 4 cyl and all 6 in the third position. I never thought much about mine being only 2 stage on my C 13 was more irritated with the trans slamming into 4 gear when I took my foot off the pedal. Is yours set up that way where the trans downshifts when the engine brake come on?