Flying Finn Posted February 21, 2018 Report Share Posted February 21, 2018 We have a 2001 Volvo 770 with a Cummins ISX equipped with a 3 stage engine brake. It doesn't always work when I flip the switch. I have had the ECM programed so that the brake should work with or without the cruise control being turned on. Sometimes it works going down hill or slowing for an exit ramp. Never know until I try it. Before I take in for repair was wondering what you guys think could be the problem. Thanks Brad Link to comment Share on other sites More sharing options...
DesertMiner Posted February 21, 2018 Report Share Posted February 21, 2018 Sometimes the brake or clutch engage/disengage switch(s) will get old.....or the pedals are not returning to the right position. Try putting your foot under the clutch pedal and lift up to engage the switch and see if cruise will engage. Try the same on the brake pedal. You may have to hold both pedals to engage the switches. Some folks have used a small bungee cord to "lift up" on the pedal(s). Link to comment Share on other sites More sharing options...
chooseopen Posted February 21, 2018 Report Share Posted February 21, 2018 I actually implemented the "bungee" trick on my 2007 VNL670 brake pedal to keep the cruise-control on. I know that there is a procedure for adjusting the brake pedal on the foot valve. Below is what I found online,. If anyone can verify this procedure, I would be thrilled to get rid of my bungee! There is a procedure for brake pedal height adjustment. The adjustment screw is at the top of the foot valve. it is an allen head screw with a 13mm locknut. Screw it in till you have .16 to .32 inch of free play.. That should fix it. Make sure your air pressure is up when you do it.. I had to do mine cause the guys in our shop were gonna go the spring/ bungee cord route.. There is a right way to do most things and a wrong way to do everything. 2007 Volvo VNL670, Singled, Air ride hitch Link to comment Share on other sites More sharing options...
Showme Posted February 21, 2018 Report Share Posted February 21, 2018 Jake's are usually set to disengage at 1100. Are the revs below 1100 when you let off the throttle? Throttle must be at no fuel. Engine temp above 110. Brake and clutch full up position. Just my 2 cents Volvo VNL / Missouri Titled RV Ved12 425HP Super 10 Spd 37ft KOA Fifth Wheel Jeep Rubicon Toad Link to comment Share on other sites More sharing options...
Bob A Posted February 22, 2018 Report Share Posted February 22, 2018 Engine brake should still work with brake applied but clutch pedal has to be up rpm above 1100+- engine temp up to operating temp 2014 jayco siesmic 3914 1998 volvo 610, singled short ( bought in 2005) 14 speed volvo tranny 2014 Toyota yaris Link to comment Share on other sites More sharing options...
rickeieio Posted February 22, 2018 Report Share Posted February 22, 2018 To the left of your Jake selector switch is the on/off switch. Be sure it is working properly too. KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
beemergary Posted February 22, 2018 Report Share Posted February 22, 2018 Time to get out your voltage tester and do some backtracking. On my older Pete with a Cat. (doesn't matter) there's a switch on throttle and clutch. Link to comment Share on other sites More sharing options...
jenandjon Posted February 22, 2018 Report Share Posted February 22, 2018 19 hours ago, DesertMiner said: Sometimes the brake or clutch engage/disengage switch(s) will get old.....or the pedals are not returning to the right position. Try putting your foot under the clutch pedal and lift up to engage the switch and see if cruise will engage. Try the same on the brake pedal. You may have to hold both pedals to engage the switches. Some folks have used a small bungee cord to "lift up" on the pedal(s). Sometimes you have to do that with new trucks too. Farmer, Trucker, Equipment operator, Mechanic Quando omni flunkus moritati-When all else fails, play dead I'm a man, but I can change, if I have to, I guess. Link to comment Share on other sites More sharing options...
Pete Kildow Posted February 23, 2018 Report Share Posted February 23, 2018 Seen one fixed 2 weeks ago. His was doing that same deal. It was the on/off switch. It had gotten where it would be on. But not making contact. Tim put a new switch in for the guy. And told me they had 12 in last year. 9 of them were the switch, rest of the Clutch switch. But on those curse was acting up also. Link to comment Share on other sites More sharing options...
porky69 Posted February 23, 2018 Report Share Posted February 23, 2018 Is the ECM set so that the Jakes only come on with the service brakes? Only have to tap the brakes enough to activate the jakes then let them do the braking...you may not realize that you are doing that when they work..or it could be some of the stuff above. Link to comment Share on other sites More sharing options...
beemergary Posted February 23, 2018 Report Share Posted February 23, 2018 13 hours ago, porky69 said: Is the ECM set so that the Jakes only come on with the service brakes? Only have to tap the brakes enough to activate the jakes then let them do the braking...you may not realize that you are doing that when they work..or it could be some of the stuff above. Get a non computor truck (mechanical) and some straight pipes. You'll know if there working. Link to comment Share on other sites More sharing options...
Flying Finn Posted March 9, 2018 Author Report Share Posted March 9, 2018 Turns out it was the on/off switch. I ordered the on/off and 3 stage switch from Volvo. Total cost $100.00. Would have cost me $150 to have Volvo diagnose the problem and then add parts/labor on top of that for the repair. Many thanks to Pete Kildow. Saved me a bunch of money and aggravation. Link to comment Share on other sites More sharing options...
HERO Maker Posted March 9, 2018 Report Share Posted March 9, 2018 I like those things that get fixed for under a grand!!!! Way under. Rocky & Sheri Rhoades '01 Volvo 770 2016 DRV Mobile Suites, HoustonHERO Makers Ministry Link to comment Share on other sites More sharing options...
Pete Kildow Posted March 9, 2018 Report Share Posted March 9, 2018 7 hours ago, Flying Finn said: Turns out it was the on/off switch. I ordered the on/off and 3 stage switch from Volvo. Total cost $100.00. Would have cost me $150 to have Volvo diagnose the problem and then add parts/labor on top of that for the repair. Many thanks to Pete Kildow. Saved me a bunch of money and aggravation. Glad It helped out. So often shops charge hours and hours. To track down something, when it turns out to be the simple things. Link to comment Share on other sites More sharing options...
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