JD 300B

Hey everyone. You'll never believe it but I've got tractor problems. Lol. I bought a JD 300b last week. The guy was pretty up front about the issues he knew of. The main one was that it had been flooded. I'm down here in Louisiana and we had a couple big floods last year. The guy said when he found the tractor all he could see was the top of the backhoe. He drained the diesel and changed the fluids in the motor. He started it up for me and it sounds good. The problem is with the hydraulics. He said that when he fired up the tractor that everything worked but started to slow down then finally quite. So yeah there was water in the hydraulics.
Anyways we loaded up the tractor and I took it home and drained the hydraulics and changed the filters. I drained the lines from the backhoe to pump, the front half. fired up the tractor and everything works except the forward gears. It will go in reverse but not forward. The tractor has a reverser on it and like I said the reverse works but won't go in forward. Also the breaks won't work either. After that I checked the hydraulic fluid and as expected it was milky again. I knew I would have to flush the hydraulics several times to get it really clean. So I changed the fluids a second time and new filters. Also the first time I removed the hydraulic sump cover under the seat and flushed the thick gunk with diesel fluid and dried it before adding new hydraulic fluid.

So, does anyone have any idea of what the problem is? This is my first tractor with a reverser on it. My other tractor is a ford 1700. Any help would be really appreciated.

Welcome to YT
It's way too late now but IMHO hyd oil & filters should have been changed before engine was started. Check reverser linkage to be sur control is shifting correctly Did you check/clean hyd oil sump screen(key 19)? I'll also suggest to check hyd filter relief valve(keys 10-12) to be sure it's not stuck.

Hi Tim. Thanks for the ideas. I did pull the sump screen the first fluid change but I haven't checked filter relief valve. I'll check that today. I did check the linkage and it seemed like it was shifting correctly to me. I can watch it shift into reverse and back up.
Yeah he should of swapped all the fluids before starting it, but his mistake is my gain in a cheap tractor. Well depending on how this all goes for me. Might be a cheap tractor, might be an expensive pain in my :shock:

One might need to disassemble the reverser control valve to determine if any of the valves are sticking due to the flood water/grit.

I was afraid you might say that, lol. I did pull the plug on the front side closest to the motor yesterday after the first fluid swap and noticed water coming out. when I drained the fluids the second time I let that plug stay open to drain from the control valve as well. Fun fact, when I pulled that plug I got a stack 3/4" tall and a 1/4" diameter washers come out. I see a spring inside but I'm assuming john deere didn't design the valve with a stack of washers for a spacer. That plug was orientated on the side and was about a 1/2" in diameter.
I also found a 1/4" plug on opposite side but located on the bottom and pulled that one as well. I did get some thicker fluid but not a lot. That made me wonder if fluid wasn't traveling freely from side to side. It just looks like a giant pain in the a$$ to get to. guess I'll find out today.

I have the Deere factory service manual here in PDF for the 300B. If you need me to post any parts of it, let me know.
I love mine. Got it at auction 15 years ago for $2200 with a newly rebuilt engine in it and new rear tires. Had to fix some
steering slop in it but otherwise no repairs. Cab looks like a toll-booth but works.

I appreciate the offer on the pdf but I got a paper copy with the tractor. I think the book is from the early 80's, but it's in decent shape.

I did manage to get the pressure relief valve out on the side of the tractor. It looked pretty good. I was able to actuate the relief spring inside it. I didn't tear into the reverser control valve yet. But when I had the floor pan up I saw there was a plug on the top of the break control valve. I opened it a it was empty except for some used hydraulic sludge. Am I wrong or doesn't the break control valve get its hydraulic fluid straight from the reverser control valve? They're both bolted together. It that's the case then there has to be something I'm not seeing clogging the reverser control valve. I also undid a plug on top of the reverser control valve and it had a ball and spring under it. The ball rides on the linkage gear. it gives the linkage that knuckled in feel when you shift from forward to reverse. Anyways it had plenty of clean fluid in the valve.

So that's all I got today. Still no forward drive. I'll break apart the reverser control valve and hopefully I find something. Is there a rebuild kit for that valve? Could that be what I need? To put in some new seals?

Fun fact: Every time I try to post a response YT says I used a weird character and won't let me post. I have had to retype this because I have no idea what character it's talking about.

When posting are you utilizing an Iphone? If so look a "Site comments" below for thread referring to posting with Iphone.

Yes IIRC you are correct brake valve gets it's oil supply to keep brake valve reservoir full from trans pump via reverser control valve.

(quoted from post at 07:50:59 12/14/17)

Hi Tim. Thanks for the ideas. I did pull the sump screen the first fluid change but I haven't checked filter relief valve. I'll check that today. I did check the linkage and it seemed like it was shifting correctly to me. I can watch it shift into reverse and back up.
Yeah he should of swapped all the fluids before starting it, but his mistake is my gain in a cheap tractor. Well depending on how this all goes for me. Might be a cheap tractor, might be an expensive pain in my :shock:

Click to expand...

Regarding checking the linkage as recommended by TX Jim.

I think the linkage on yours is similar to my 401 there is a shaft that goes from the drivers side underneath to the reverser control on the pass side.
Roll pins are used to connect the tube to the shaft going into the valve.
I had one pin that was cracked, everything visually looked like it was functioning but the travel was just a hair short of what was needed.
Replaced the pin, problem solved forward travel returned.

I went and took a look at it. I undid the linkage and actuated the reverser control without the linkage and same deal. goes in revers no problem but not in forward. Basically I'm just dragging a$$ now. The thing is sitting outside and it's cold out there..Lol. I know I should go tear into it but I just don't want to.

TX Tim, when I pulled the plug off the top of the brake valve it was empty but the reverser control valve had fluid in it. What does that sound like to you? You think that maybe my whole problem is a clogged up reverser control valve? I did end up filling the brake valve through the plug I pulled and the breaks regained some feel to them when I pressed the pedal down. before without the fluid in there it just dropped down with no resistance. I would like the problem to be in the reverser control valve, we both know that is the easier and cheaper fix than splitting the tractor. But if I have to I will split it, I'd just like to narrow it down before I take that big of a step.

On a side note if anyone knows of someone selling an old stabilizer ram I'd like to know. The old owner did some creative repairs to the old one.

My knowledge of industrial tractors is very limited plus I don't have an ind tech manual to view. Maybe JDEM or some other tech will "chime in"?

Can u send me pdf of tech manual 300b? Send to [email protected]. Thanks!,,,,,