I'm new to this forum and can't find an answer. I'm working on a D4H series 2 and the park brakes won't release. It will drive thru them but dragging very badly. The dozer is miles out in the back country and I'd like to release the brakes to get it to a lowbed and into my shop. On my 5B there's a bolt for each side under the seat for mechanical release, but this is a whole different animal. TIA. John 47
Any chance of a S/N? Always get the best answers that way! The only thing I'm seeing in a D4H II is a track skidder. S/N might get me to the right place! Just for kicks here is what it says on SIS for the D4H Series @ skidder, attached file:
It's definitely a dozer! Hopefully the I'd plate is legible.
Read through here HeavyEquipmentForums
That's the one I originally read through. I didn't see anywhere it mentions being able to cage or release the brakes on a machine that's not running. My theory is that if I can release the brakes on a machine that's not running then I can move it to a lowbed.
Dead machine... Block machine from rolling. Remove center from final drive cover. Extract sun gear (may need to rock machine to relieve tension). Once both sun gears are out, the machine will freewheel (no way to stop unless tethered or pushed).
What I want to do is release the parking brakes. If there's a way to release the parking brakes manually it can be driven. I wish there was a book available for me to look through but no luck on that. Almost every machine I've ever worked on has some sort of manual release or way to override. This can't be the exception,,,, I hope!
I dont recall seeing a brake release procedure. What I just described is simple, albeit you'll need another machine to push or tow it. I called the shafts sun gears, but technically, they are axle shafts. And, I dont believe you even have to drain the gearboxes. Shirley, someone else will join in and confirm.
Answered here - HeavyEquipmentForums The brakes can be pressurized using an external pump to release them.
Thanks for the research and the reply. What I was hoping for was a mechanical release of the park brake so the machine could be driven a considerable distance to where it can be loaded on a lowbed and brought into the shop.
I'm having a problem understanding this situation. Are you saying that the machine does run and move but something is wrong with the parking brake system that prevents it from releasing?
It's a long story. This dozer runs and drives. The brakes are stuck. It has sat for 6 months or better and miraculously didn't burn. It is miles behind a fire line in the SCU complex fire, now contained. The roads are trashed. I can't get a service truck to it. If I could get it to release the brakes in any manner I could get it into my shop. I can get a lowbed to the same spot as a service truck do bringing it in makes more sense to me. The linkages APPEAR to all be free. I'm heading back out there now to wiggle and beat on it some more. I wish I could get a truck to it but I can't and it's near impossible to pack everything needed to it in a damn jeep.
So I'm assuming you don't have another machine available to tow it? Actually would need two machines to be safe, one to pull from one end and one at the other end to act as the brakes. And they would need to be of the same size or bigger unless on perfectly level ground which I'm guessing is not the case. One question also would be why it has been sitting for 6 months, would it be because of the brake problem? I'm starting to wonder if there was some major failure in the brake system that could make it impossible to release the brakes even if you did have the pump to work them.
It just hasn't been needed. It's on a couple thousand acre ranch and there's other machines that are bigger and newer so it's been parked out of the way. I just got back from checking everything over AGAIN. Linkages ect. It runs great but the brakes are FUBAR. I officially give up! I'll build a new road down to it when time permits and bring in an outside Cat service to look at it. I really could put it to use for the angle blade but it's about a 4 on the priority level of 10.
I would think you could plumb in at the top of the trans filter and t it off to the two test ports for the brakes they should be the two inside ones on the steering brake valve. have you put a gauge into the brake test ports to see if they are pressurized if you don't have pressure to the valve you wont have steering either