| Author |
Message |
Nick Russell (66.82.9.26)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 13, 2004 - 11:32 pm: | |
In addition to the earlier post on my air brakes, also have a second problem. Been sitting still most of the winter and on the road heading north now. My jake brake has stopped working. I checked the switch in back and have voltage at the swich, but when I try to use the jake, nothing happens. |
Bill Gerrie (209.50.74.21)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 14, 2004 - 4:35 pm: | |
Nick
There is a series of things that have to work for the Jake to work. There is a switch on the transmission that closes when the tranny is in lockup on an automatic. There is also a switch on the throttle. This can be a micro switch on the throttle or a switch in the govenor. Each one of these switches have to close to get the Jake to come on. You might want to bypass each switch with the bus sitting and the Jake switch on see if you have voltage at the wire on each head where it enters the heads. I had a problem where the wire broke off inside the head due to vibration. You can check the solenoids with an ohmmeter if you take a reading at the connector on each head after you remove the wire from the bus. You will get a reading if they are okay and no reading if the wire is broken off inside. Hope you can understand what I am trying to explain to you. Bill |
Doug (68.83.23.33)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 14, 2004 - 9:02 pm: | |
I have a maint manual if your interested. |
Buswarrior (Buswarrior) (64.229.211.226)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 14, 2004 - 10:01 pm: | |
Hello Nick.
Failure of electrical things after sitting is almost always ground or corrosion related.
Easiest to check all the connections first and try it again.
happy coaching!
buswarrior |
Alan Kline (4.235.138.41)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 16, 2004 - 3:42 am: | |
Hay there big guy call Howard he keeps that bucket of Bolts of yours operating :~)
Paco Xpress P S Hi Miss Terry |
J@ck5b (4.27.9.125)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 18, 2004 - 3:26 am: | |
Hi Nick,
I have a converted MCI5b(PrimeTime) and I'm having the same kind of problem (Jakes not working or works only sometimes). I have already replaced the Buffer Switch a few years ago with the P/N 14435 Rev "J". I believe my problem is again in the Buffer Switch. A Jacobs Service Letter 458 (December 1996)http://www.jakebrake.com/pdf/sl458.pdf made a change by replacing P/N 14435 with a revised switch P/N 14435 with the revision letter "J". This switch can also be identified without removing it because it is plated Yellow chromate. Another Jacobs Service Letter E456 dated Oct 16, 1997 http://www.jakebrake.com/pdf/sle465.pdf introduces a new Buffer Switch P/N 01-022351 that replaces the P/N 14435 switch. I just called Detroit Diesel in Kent, WA and they do not have any in stock and have them back ordered. The price is $112.88 when available!
At this time my problem is still unresolved, I plan on removing my switch and check it out more before resorting to purchasing the new one at $112.88!
Let us know what you do to resolve your "Jake Not Working problem". Best wishes, Jack Watson |
Richard Bowyer (Drivingmisslazy) (66.168.168.57)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 18, 2004 - 6:59 am: | |
To resolve the failed buffer switch syndrome, I reqired my system so that the buffer switch was only used to control a 30 amp relay. All the current for the jake solenoids passed thru these big contacts and never another problem with the buffer switch.
Richard |
TWO DOGS (63.185.73.108)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 18, 2004 - 8:25 am: | |
THAT.....sounds like the solution |
DrivingMissLazy (66.168.175.51)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 18, 2004 - 11:33 am: | |
BTW, those little cube relays are available at most auto parts stores for less than $20.00.
Richard |
J@ck5bPrimeTime (4.27.9.125)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 18, 2004 - 6:14 pm: | |
Thanks Richard Bowyer for your solution to resolve the buffer switch failures! Would you please explain in detail how to re-wire the buffer switch using a 12V 30Amp relay ? I am refering to the buffer switch that is installed into the govenor housing of an 8V71 engine. Jake has been having trouble designing one that will last and be more reliable. I have not purchased the latest P/N 01-022351 switch yet but if the old switch is not working then a relay would not be of any help. Thanks in advance for any more help you can provide. Best wishes, Jack |
Richard Bowyer (Drivingmisslazy) (66.168.175.51)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 19, 2004 - 3:35 pm: | |
J@ck, I no longer have a bus or the schematic of the Jake system, but I will try and describe what I did. Perhaps someone with an actual wiring diagram can provide more detail.
As I recall, +12 volt DC (on my 80 Eagle) came from a source that was hot when the ignition was turned on. This 12 volts went to the buffer switch. The buffer switch contacts are closed when the rack is closed and no fuel is being supplied to the engine. (BTW, the buffer switch adjustment is critical to assure proper operation). This is the only time that the Jakes will work.
Anyway, once the buffer switch closes, it supplies 12 volts to the Jake toggle switch on the dash (sometimes thru a switch on the clutch if manual tranny) and from the Jake switch, back to the engine, thru the valve covers and to the electrical solenoids on the valve train.
My personal opinion is that it is the solenoids that are causing the failure of the buffer switches. The switches are very small micro-switches and their current capability is very limited. I suspect that the continual closing and opening of the solenoids is causing a large current inrush that is damaging the contacts of the micro-switch.
I re-wired my system so that the DC voltage leaving the buffer switch went to a heavy duty cube type relay. When the buffer switch closes, all it has to do is energize this control relay, which only requires a few milli-amps of current to close. Definitely not enough current to harm the buffer switch contacts.
The control relay has 12 volts connected to one contact and the other contact goes to the Jake switch up front, just as the buffer switch wiring previously did. After making this modification I never again had buffer switch failures for the several years I had the bus after that time.
Hope some of this makes sense.
Richard |
J@ck5b (4.27.9.125)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, May 20, 2004 - 3:12 am: | |
Thanks Richard for your information, I have printed this out for future reference when I find time to check it out the system in more detail.
Thanks again, J@ck5b |