brakes won't disengage, engine running idle; 0 psi read from brake control valve test port with parking brake off or with service brake activated. main relief pressure reads 400 psi, engine idle no error codes concerning trans/brakes new solenoid valve for parking brake and service brake were installed, tested voltage to solenoid, key switch on, 25.5v to both parking and service brake valves were read. it was all we could have done today, not sure what else to check. Not sure if it has anything to do with the brake release, but the tachometer/gear display fills up & flashes zero's throughout the screen. Any advice would be greatly appreciated. Thanks in advance
just thought i'd update on this, managed to get it going yesterday; had to remove the brake control valve bank, just 4 #14 bolts to take out, then removed the proportional solenoid valve from the valve block, serviced it up since the coil and rod was corroded, also went ahead and disassemble the entire block by removing all the #13 bolts and carefully separating the upper & lower block manifold, strainer inside was clogged, spools were stuck, after re-assembling and starting her up got 400 psi when parking or service brakes were disengaged... all good to go.
Sounds like you did a good job getting her going, any thoughts why the valve was so dirty?
Yair . . . good one shinigamix2x . . . it is always good when folks to get back and post progress and how they resolved problems. As DPete mentions it would be interesting to know why that particular valve bank became gunked up and corroded. Cheers.
Wish i knew the history of this machine, it has over 8000 hrs and this is the first time I've ever worked on a tractor, i'm a new apprentice this week and from observation the oil was black and sooty in the manifold compartment, like carbon deposits. If i were to say any more i would be guessing, like mixing different grades of oil, asked around for info from others and heard mechanics swapping the solenoid brake valve assembly on top the brake a lot of times in the past, so exposure to dirt and moisture when they were doing that could contribute, poor maintenance and operation on the field is a norm here, so I've been told. Wanted to check the transmission filter and screen but the super told me as long as the machine moving there's enough oil passing through the filters to engage the clutches. Had to jump to another repair, can't get a chance to find the root cause of the problem, or a chance to appreciate the work. Sigh, it sucks but i'm really grateful for the experience i'll earn here.
I'll have to work again on this tractor concerning the "Tachometer/Gear Change Display" only showing "Zeros", will have to run through the harness and check the part number of this display to make sure the correct display was installed and wired properly. Apparently swapping parts here is the only way to repair an equipment.
Ah-ha - the good old "Fault Finding by substitution" method ................. keep changing things until it works, and it must have been the last thing you changed. Meantime you have all the parts you changed up to that point lying in a heap on the floor and you have NO idea what you're going to do with them ....... If you need a wiring schematic for the D6R PM me with the Serial Number and your e-maill address.
Haha, that's exactly what goes on here, Thank you for the assist Nige, i've read a lot of your posts, very informative and easy to follow. I have access to the repair manual at work, but i still lack the basic understanding of the systems operation and troubleshooting aspect of the repairs. Will take my time tomorrow, reading, understanding and making a list of what to check and then see what i can do, if efforts were successful i'll post my findings here.
Hopefully your Service Manual will still have the electrical schematic folded up in the back of it, they often go walkabout ......... Here's a tip. On the electrical schematic each part (like the tachometer/gear display you refer to, or a sensor for example) will have the part number marked right next to the item on the drawing. If the numbers are different between the schematic and the actual part it may help you to identify whether or not someone has installed a part from another machine on your "problem child". I've highlighted them on the attached diagram. Also if you look at each connector on the diagram below each one is marked E-C9, E-C10, E-C12, etc. That means the wiring harness feeding all these items is Reference "E". Somewhere on the schematic will be a table listing the Part Numbers of every harness on the machine, just look for "Harness E". It's often easier to find a harness number on the electrical schematic than it is to look it up in the Parts Book.
Is this for the D6R-II "FDT" Serial # prefix?, i'll just work with this info first thing in the morning. There were some stuff i wasn't aware of in the schematic that you pointed out, like the part numbers and the harness identification. Thank you again for this. Makes troubleshooting a lot more fun when there's less guesswork
I just picked a 6R Series II at random, I don't think it was FDT prefix.