I recently purchased this older cat. I set both brakes. I can't get them to release and of course the machine cannot move
Are you pressing the service brakes at the same time as you attempt to release the parking brake..?
Thanks for te rapid reply Nige. Yes, I pull up on the release lever and stomp the pedals. I have many hours of experience on these old cats and kick myself for ever applying the brake. they are notorious for being hard to release If you forget which way to use the lever and get them too tight. But this is the first time I can't release them. the left pedal can be pushed to the wall with effort so mabey that's why I can't
Nige, the serial # is 6X612. It seems short for a serial#. She's a strong runner, great undercarriage, everything works. she must have had an easy life
check oil in ring gear and trans and ljnkage that is manual
Thanks dozr for the reply. I will do that.
Sorry, I wasn't aware that you had experience, it was never mentioned in your OP. Possibly a case of "some disassembly required" in the linkage, then set and adjust to spec maybe..?
Check your linkage, will bet have a pin frozen up.
See if these attachments are of any use.
Thanks for the great suggestions everybody. I am accessing the linkage hoping I can solve it there. The attachments are a help Nige as the manuals will take time to arrive. I would like to see a parts manual schematic of the parking brake mechanism. Thanks for all the help!
Just recently had a '74 7F that I couldn't set the park brakes. Had set outside all winter, was just rusted linkage pins. Tilted the seat and pulled 1 floor pan. a generous ammount of liquid wrench and was back in business.
The Parts illustration in in 3 sections......
Thanks sled dog I do Suspect linkage and have been applying lubrication and trying to work things as forcefully as I dare. Thanks for the parts schematics Nige, they really help. I'm going to start taking off linkage If nothing is frozen I'll take off those two front covers. I appreciate the help everybody
Remember to post photos........
You're right Nige I need to learn how to post pictures. I'm computer illiterate. My wife can probably show me how. I am disconnecting winch, blade, shift controls and will lift everything off for better access. there is no opening under the seat.
I guess I don't understand this much. All those machines I worked on just had the lever on the right side that linked to a dog under the floor boards. There was a rack that moved with the brake pedal linkage on the right side pedal. Pushing the lever forward moved the dog to engage the rack and hold the pedal in the down position. The problem when the brake wouldn't release, was the brakes hadn't been adjusted in a long time so the pedal was near the dash panel wall and wouldn't allow the pedal to travel far enough forward to disengage with the rack to release the linkage. On one machine I had to pull the floor plates and follow the linkage till I found the rack and dog. Had to use a bar to pry the dog out of the rack to release the brake. One other bit is that you have to pull the lever back when you step on the pedal to release the dog.
John C. I've got an old D7 with an external dog like you described. This D6D has Internal dogs on both brakes and the one lever sets either brake or both depending which pedal or pedals you hit. You were right about the brake adjustment. I was using the set and release lever the wrong way so got them quite tight trying to release them. Operator error. one pedal was hitting the wall so I could no release it. This dozer has no under seat access. so I lifted seat with all the metal assembly around it as high as the rollover protection allowed, about 3 ft. Then adjusted the throw on my pedals, checked my brake linings. all's good back together. Thanks to all for really great help