View Full Version : Cat 257 parking brake issues
06-03-2011, 11:06 AM
Recently replaced the alternator on my 257 and I noticed yesterday when you hit a bump or any kind of sudden jaring actiion it will engauge the parking brake. Doesnt matter if the machine is moving or not. Not sure the alternator has anything to do with it but it wasnt doing this before I swapped it. Has anyone experienced this?
06-04-2011, 09:13 AM
Same thing was happening on that boat anchor 450CT I used to own.
First I thought it was the saftey switch on the seat and messed around and messed around with that because it only happened when the machine took a good jolt, but that wasn't it.
Took awhile to track it down but I finally did.
There was a saftey switch that activated when the cab was raised. The problem was that the switch adjustment was maxed out at the factory and barely being activated so when that machine took a good jolt the cab or switch would move just enough to activate the parking brake. Had to weld a taller tab to activate the switch more fully since it couldn't be adjusted down any further.
Just one of the many, many reasons why I hated that machine.
I don't know if Cat has a safety switch between the cab and the frame or not but you could check there or check the safety switch at the seat and at the door if you have an enclosed cab.
06-04-2011, 10:35 AM
There is no saftey switch for the Cab on CAT ... We have had it happen where there was a loose battery connection even tho the machine did start fine but the park brake engaged intermitent just like you say :cry: maybe check the Battery connections .
06-04-2011, 11:36 AM
there is also a saftey switch on the lap bar that could need adjusting...
06-04-2011, 10:43 PM
parking brake has a solonoid that may be acting up. Also the PLASTIC gear piece between the pump and the engine could be stripped out. both have happened to me. hopefully it is the solonoid
06-05-2011, 07:55 PM
Thanks guys. It was the ground wire on the back of the anti theft switch loose. Tightened it up and didn't have that problem all day
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