Hi all, I'm on a remote job and am tasked to load equipment on barge. I am the crane operator and have no experiance with scrapers. We have a 615c that can't get brakes to release without draining air tanks , which is backwards to everything I know! I have tried all of the combos with air charge and air valve. Also, the service brake seems frozen and won't depress or release. Any help would be appreciated
Don't know what to tell you about the parking brake. But I know service brakes tend to not last long on a pan, and generally they are not high on contractors to do lists. Please be very careful getting it on or off that barge. Maybe if you have a big enough rig there, pick that 615 with the crane and set it on the barge?
I'm not familar with the 615, but it sounds like the treadle valve (valve under the pedal) is stuck on, which means any time you have air pressure in the tanks the brakes are on. I worked on 613's way back and I don't recall any spring brakes anywhere, no air pressure no brakes. If there's any way possible, get the brake pedal freed up or changed out, should solve your problem I think.
Sounds like a good possibility! I'd spray the peddle with penetrating oil and apply a bit of hammer action to it to see if it will free up. Tap it down and pull it back up. Or if you can unbolt the peddle from the valve and remove it. under the peddle there should be a plunger that works the valve it could be corroded in the top of valve. I was asked one time to do a side job of rebuilding a transmission in a 950 or similar sized Cat loader for a local junk yard. Guy said it was bad and would not shift into gear. Decided to do some quick checking before starting the project. Noticed the brake peddle was a bit stiff. Yanked it up good and all of a sudden the machine started to move. Soaked it with penetrating oil and worked it up and down a few times and it was nice and free. Did some laps around the guys parking area in forward and reveres. Then went in and told him there was no problem with the transmission. I think he was shocked that I got it working in less than ten minutes. I think he paid me $50.00 for a ten minute job that did not involve turning one bolt, just a squirt of penetrating oil, and I "borrowed" that from my day job!
I took a look at SIS and the 615C I checked on shows a drum type parking brake on what looks like the rear of the transmission with a spring brake chamber connected to the lever. If you know the actual S/N I could see what it shows for that one. The one I saw was a 5TF prefix A little info off SIS, there is a Secondary brake system description as follows: The secondary brake control valve has control over the supply of air to the secondary brake pilot valve and the scraper relay secondary valve. When the engine is first started and knob (1) is pulled OUT, the lines to the pilot and relay valves have no pressure in them. There is no pressure air at the scraper relay secondary valve or scraper reservoir so the scraper wheel brakes are not activated. There is no pressure air at the control passage of the secondary brake pilot valve so pressure air goes to the air chambers of the tractor wheel brakes. The tractor wheel brakes are activated. When knob (1) is pushed IN, air pressure goes to the scraper relay secondary valve and on to fill the scraper air reservoir. Air pressure also goes to the control passage of the secondary brake pilot valve and stops the flow of pressure air to the tractor air chambers. The tractor wheel brakes are released. Then all of the air reservoirs on the tractor and scraper are full of pressure air, the secondary brakes at all four wheels will now be activated by the secondary brake control valve. Now, when the knob is pulled OUT, the flow of pressure air from the control valve is stopped and the wheel brakes are activated.