MACK321

Hello I have a 2011 Mack CXU613 I'm having a problem when I brake bobtail or driving empty my passenger rear axle locks up making it very hard to stop and I don't hard brake just a little tap to the brake makes the axle lock all my speed sensors are new brakes are new I replaced the brake chamber for the rear axle as my mechanic thought that was the problem turned out not to be anyone have had this issue before?

Hey guys it fixed the problem when replacing wheel speed sensor

Your the man onyx610 thanks for the support and advice I'll let you guys know on Monday gonna take a load and hopefully test it out

So picked up my truck from the shop brought it home went straight to the rear axle speed sensor found that the speed sensor is bad on the rear passenger side gonna wait Monday to get parts to replace it when I unplug it I lose my speed I hooked it up to the driver side and so far it hasn't messed up with the passenger side not hooked up hope that makes sense I'm not a handy guy but you guys made me work on my truck and big help thank you guys I hope this is the problem

Please thank you anyone that figures out my problem you will be gifted

Joey Mack i haven't done that I will check that for sure tomorrow

Onyx610 I have eaton fuller transmission 13speed

I have a 2011 Mack cxu613 w/MP7. I am having an issue with the Speedo randomly dropping out which cuts power. If stop & kill the truck & wait for all the instruments to turn off then start back up the Speedo then works until it randomly does it again. The fault light does not come on. If you are going down the highway when this happens I can just turn the key off until all instruments turn off then turn back on & it returns to normal until next time. Very random - 5 minutes, 15 minutes or maybe even 45 minutes apart. Replaced speed sensor and speed sensor harness truck been to 5 shops no one can figure it out couldn't get up to 45mph loaded please help me