Jake brake failure
 

Jake brake failure

Started by fraser8, July 11, 2009, 08:12:59 PM

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fraser8

I'm on a tour of the mountains of southern British Columbia heading for a Model 'A' meet in Cranbrook. Yesterday the jake brakes came on while the bus was parked at an idle, quite a racket, I solved the problem by turning the switch off, thinking that I could turn them on while going down hill. Now they don't engage at all. Any ideas out there, I can take it to a truck repair place in Cranbrook but if at all possible I would like to fix it myself. Not that I'm cheap but I've been known to be thrifty.  I miss the old friend while going down the long hills................
Fraser Field
Deroche, BC, Canada
Where the milk cows out number the people, but they can't vote
1972 Prevost, Detroit 8-71/740 Allison automatic, Jakes
Hobbies: restoring classic cars, www.oldambulance.com, arranging old car tours: www.coasters2010.com, www.canadiancoasters.ca
Retired Paramedic

luvrbus

You have a buffer switch problem check and make sure the lock nut is tight but be careful not to try and adjust it if you don't know anything about Jakes. Does your switch have the hi idle feature.      good luck
Life is short drink the good wine first

fraser8

I have a separate high idle switch, and the jake switch has a high/low/off position. I don't know a lot about the jake brake system but if I have an idea I can take it in and sound good and not get ripped off. thanks luvr, I appreciate the info.
Fraser Field
Deroche, BC, Canada
Where the milk cows out number the people, but they can't vote
1972 Prevost, Detroit 8-71/740 Allison automatic, Jakes
Hobbies: restoring classic cars, www.oldambulance.com, arranging old car tours: www.coasters2010.com, www.canadiancoasters.ca
Retired Paramedic

luvrbus

Fraser, you have the hi idle Jake buffer switch that is a very expensive switch and most can be repaired the pin falls out , the spring goes bad or the lever made of plastic breaks.A  little advance warning for you that switch cost over 600 bucks now. 
If you can do without the fast idle one will cost you about 230 bucks     good luck
Life is short drink the good wine first

Timkar

Saw you as you were leaving a fruit market in Keremeos yesterday. You're right it was sounding bad. As soon as the wife came out I tried to find you but you must have taken Hwy 3 to Ososyoos and I was heading up to Penticton on 3A. Hope you get your problem fixed. Nice looking Prevost...maybe we'll meet up next time.
Tim
Cawston, British Columbia

fraser8

I was wondering why I had no power, tough starting off with the jake on. Sorry I missed you. Fraser
Fraser Field
Deroche, BC, Canada
Where the milk cows out number the people, but they can't vote
1972 Prevost, Detroit 8-71/740 Allison automatic, Jakes
Hobbies: restoring classic cars, www.oldambulance.com, arranging old car tours: www.coasters2010.com, www.canadiancoasters.ca
Retired Paramedic

lostagain

In Cranbrook, take it to Inland-Kenworth, 816 Industrial Rd. #1, 250-426-6205. I take the hockey team's bus there every 6 months for the DOT inspection. Really good people.

Another good place is the DD dealer: Cullen Diesel Power, 601 Industrial Rd. #3, 250-426-8271. The manager John knows a lot about 2 stokes.

JC
JC
Blackie AB
1977 MC5C, 6V92/HT740 (sold)
2007 Country Coach Magna, Cummins ISX (sold)

TomC

In a pinch, you can jump the buffer switch, or any of the other switches to make the Jake work.  But then you can only turn it on when you have your foot off the gas pedal and have to turn it off before coming to an idle (in another words-work it manually).  If you do try to accelerate with the Jake on, it will tell you quickly with much smoke and no power.  Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

fraser8

Here we are on the road, Thanks all for the help, I'll fill you in on the out come....
Fraser Field
Deroche, BC, Canada
Where the milk cows out number the people, but they can't vote
1972 Prevost, Detroit 8-71/740 Allison automatic, Jakes
Hobbies: restoring classic cars, www.oldambulance.com, arranging old car tours: www.coasters2010.com, www.canadiancoasters.ca
Retired Paramedic

johns4104s

Luvrbus,

I do not have the high idle so my jakes would be less expensive.

John

Buffalo SpaceShip

Follow TomC's advice. To take it further, pop the valve covers off and check for power at the solenoids... then apply power to the solenoids one by one.  They will not move much w/o the oil pressure, but you'll definitely see if they're working or not. I was able to diagnose a faulty solenoid this way and pick up a new one at Stewart & Stevenson whilst traveling.

HTH!
Brian Brown
4108-216 w/ V730
Longmont, CO

JackConrad

Jakes can fail mechanically (O rings) as well as electrically.  Jack
Growing Older Is Mandatory, Growing Up Is Optional
Arcadia, Florida, When we are home
http://s682.photobucket.com/albums/vv186/OBS-JC/

Stormcloud

Darn nice looking runabout on that trailer, Fraser. Hi to Dorothy from us.

Mark & Donna
Mark Morgan  
1972 MCI-7 'Papabus'
8v71N MT654 Automatic
Brandon, Manitoba, Canada in summer
somewhere near Yuma, Arizona in winter(but not 2020)

fraser8

All is fixed. The wire running to one of the solenoids was scufffed during the installation years ago, inside the cover, it finally shorted against the block and shorted the solenoid out. I replaced the wire and the solenoid. Everything is working wonderful...
Fraser Field
Deroche, BC, Canada
Where the milk cows out number the people, but they can't vote
1972 Prevost, Detroit 8-71/740 Allison automatic, Jakes
Hobbies: restoring classic cars, www.oldambulance.com, arranging old car tours: www.coasters2010.com, www.canadiancoasters.ca
Retired Paramedic

johns4104s

I talked to a guy today that was against having Jake's,s he said that if there running they are good, but if they start giving problems they can be a nightmare, even damage your engine. He also said they have stopped offering them on the new trucks.

2 cents worth?

John