Shop Floor Talk

Shop Floor Talk (https://www.shopfloortalk.com/forums/index.php)
-   Mechanical & Electrical (https://www.shopfloortalk.com/forums/forumdisplay.php?f=36)
-   -   3 Point NO lifty lifty Case David brown 885 (https://www.shopfloortalk.com/forums/showthread.php?t=50228)

Ironman 12-16-2018 10:34 AM

I know you have gone over all that stuff, but do you understand it's function, and can you visualize and run it in your mind?
I have the ability to run something and cycle it and usually when I am asleep at night and wake up to piss, the answer will show itself.
That does not mean every time this works.
The JD Model B was a case in point. I spent a year tearing into every aspect of the oil pressure and pump and filter system and removed and inspected them all, and every pipe and passage.
At last resort, I pumped oil into it from a pressure tank through the oil pressure gauge line to get lube to the bearings to prevent bearing damage from every time I fired it up dry without pressure.

Then it started pumping oil, and I'll never know why, but it took a year to succeed.

If you cannot clearly visualize how and why a hydraulic circuit does act in normal usage, I suggest you find a mentor who will help and explain what and why the thing does that.
I'm sure that in my case if I had somebody who was familiar with a JD B tractor he could have told me the answer in a heartbeat.

You need to find that guy. And the first question he will ask you is what is the system pressure that is produced? You need to know that. Not what it should be, but what it actually is.

MetalWolf 12-16-2018 06:31 PM

Well got back in to it and have a broke line inside the axle housing and that ain't no fun! :( double the trouble an no fun what so ever to do on these things.... I tell you if shit can go wrong it will go wrong.... you will know what I mean in the artic cat thread

MetalWolf 02-10-2019 01:27 PM

Well getting back to the selectromatic hydraulic system on this Case David Brown...

Took it all back apart last night and going to go through the valve body again, odd, part is I have hyd. pressure going to the axillary.
but no hyd. fluid or pressure to the valve body I'm guessing I'll have to rip the pump out and see what's going on in it

wondering if there are two sides to the pump that supply the circuits if they are separated.

MetalWolf 02-13-2019 07:42 PM

2 Attachment(s)
I'm not sure but I might be looking at this all wrong but it appears that the auxiliary valve body supplies the fluid to the TCU valve body then the TCU supplies fluid to the 3 point piston and then back to the low-pressure line to the pump.

I'm a bit confused and not sure if I am seeing it correctly on the piping diagram
I'm going to need to walk away from it for a few as it is just frustrating the crap out of me... but it does appear the high from pump runs through the auxiliary control valve before it reaches the TCU valve body that then supplies fluid pressure to the 3-point...

anyway I met my match on this one it just keeps kicking my ass I fix one thing and something else is fudged up:(

but by chance, I could be looking at the piping diagram wrong or am I?
here is a diagram of the piping I have 1800 psi going to the auxiliary control valve but I have no pressure actually no fluid going to the TCU and I'm thinking the auxiliary control valve works in three positions
Attachment 149365Attachment 149379

MetalWolf 02-14-2019 06:46 AM

3 Attachment(s)
Attachment pics without the gibberish piping and TCU valve and auxiliary control valve looking at it look's like fluid is going through the auxiliary valve first then to the TCU valve which sends fluid to the 3-point piston cylinder.
Attachment 149384Attachment 149385Attachment 149386

MetalWolf 02-16-2019 05:13 PM

Ok now I have the issue figured out the problem laid in the auxiliary control valve being it is a three-way directional valve and bypass, it was stuck in a manner it appeared to be a two way only.

But would not have known unless it was taken fully apart... which turned out to be not just one issue with this thing but just one of three, the cam to the TCU draft control was sheared off.

The TCU valve was full of garbage and some rust from water sitting in it and then the auxiliary valve was in position for the bucket attachment and the internal parts were bent from it being forced, And so the actuator and spring were seized in the actuator positioning housing.

So now I have ripped it all back down and in doing so I found loose bolts to pump shaft and PTO shaft drive socket coupling just ready to fall off into the bull gear housing.

But I did find the broken stud bolts and nuts from the lift arm camshaft...

So now tomorrow, Is another day and will be putting all the crap back together and hopefully, I have no issues like before getting the feeder line attached back to the TCU valve.
It is the worst part of the repair 6" curled bent tube to fit in a space only 2" wide not an easy thing to do. And no simple easy way to do it...

Whitetrash 02-16-2019 06:05 PM

Quote:

Originally Posted by MetalWolf (Post 730848)
Ok now I have the issue figured out the problem laid in the auxiliary control valve being it is a three-way directional valve and bypass, it was stuck in a manner it appeared to be a two way only.

But would not have known unless it was taken fully apart... which turned out to be not just one issue with this thing but just one of three, the cam to the TCU draft control was sheared off.

The TCU valve was full of garbage and some rust from water sitting in it and then the auxiliary valve was in position for the bucket attachment and the internal parts were bent from it being forced, And so the actuator and spring were seized in the actuator positioning housing.

So now I have ripped it all back down and in doing so I found loose bolts to pump shaft and PTO shaft drive socket coupling just ready to fall off into the bull gear housing.

But I did find the broken stud bolts and nuts from the lift arm camshaft...

So now tomorrow, Is another day and will be putting all the crap back together and hopefully, I have no issues like before getting the feeder line attached back to the TCU valve.
It is the worst part of the repair 6" curled bent tube to fit in a space only 2" wide not an easy thing to do. And no simple easy way to do it...

That bastard is just going to fight you to the bitter end. I know you'll be a happy camper when it's done.

MetalWolf 02-16-2019 06:26 PM

Quote:

Originally Posted by Whitetrash (Post 730852)
That bastard is just going to fight you to the bitter end. I know you'll be a happy camper when it's done.

It has! but I don't give in that easily ;) and once this part is done it's on to addressing the engine and cooling issues. although those are things that are not really horrible issues. and are just serious leakage that needs to be addressed... If not they are at the point of becoming a critical failure of the machine as well.

And to be honest I am not sure why I have had so much trouble with this system two hardest things to do is adjusting the TCU Valve as it has to be done with a dial indicator and be within a half thousandths of an inch on one valve and the other three thousandths... making the tool for the other adjustment wasn't hard I just gave the diagram to my buddy at the machine shop and he made it...:D

And getting the TCU valve back into the hole with the heavy lift rod attached to it and the connection tube that goes from the TCU to the ram piston with little to hardly any room to get it in there is a total pain in the ass.

But once it's done then the other pain in the ass has to come in and put the hydrostatic trans in the bobcat do all the flushing and pull the drive motors off and apart to ensure there is no debris of any kind...

but if someone asks me to take in another one identical to this well they might better brace their self... :eek:
They are going to need some deep pockets for parts for this thing, they are not cheap by any means of the word.

Whitetrash 02-16-2019 09:44 PM

The projects where you walk away and go to bed pissed off right before you just want to throw a railroad flare in the MF and cheer while they burn. I don't miss them. But, I miss that feeling of satisfaction when you finally unravel the puzzle and get to declare victory when they roll out of the shop. :D

MetalWolf 02-17-2019 05:19 PM

Quote:

Originally Posted by Whitetrash (Post 730867)
The projects where you walk away and go to bed pissed off right before you just want to throw a railroad flare in the MF and cheer while they burn. I don't miss them. But, I miss that feeling of satisfaction when you finally unravel the puzzle and get to declare victory when they roll out of the shop. :D

you weren't kidding about this POS fighting me all the way.
I got back out there about 12ish and fought with that dam spool valve seal seat
trying to get it unstuck, and it took me about three hours was getting to the point I just might have had to cut it out on the mill but it's an obsolete part and I would have to turn one out on the lathe... but then I ended up getting it out with my piolet bushing puller and some heat with the plastic welder
I use the plastic welder in sensitive places as I can direct the heat in more precise spots or places it runs 1800 deg. which is enough for the expansion of small objectives... but it's not done yet got one more but its a bushing sal with the wipe so need to be much more careful with it...

so I'm calling it a day being have a surgical procedure tomorrow morning again...:( will be down for a couple days only I hope and then I can get back to being pissed off at this thing once more:rolleyes:;)


All times are GMT -5. The time now is 11:30 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.