Early JD 310C brakes dragging

[RGM161]

Hello, I have a JD 310C hoe that is an early production VIN. I recently purchased it, during the check out the brake pedals were rock hard with no brakes. The seller stated they were blocked off and he would be fixing the brakes. The next week he called and said it was ready and dropped it off. The brakes were working unloading it off the trailer. After driving it to the barn, approximately ¼ mile the unit starting squawking horribly and wouldn’t hardly get up the hill in 1st.

I shut down and went back at it that weekend, started and worked fine, by the time I got it to the work area it was squawking again and would hardly pull. I called the fellow and received non-descript feedback…. From his sales pitch he had replaced the rear brakes and they were ok, from my inspection after the fact I see no indication the axle housings were removed.

So, I removed the brake lines at the brake valve/master cylinder and drove the unit around the field for 20 minutes with no concerns. Reconnected, bled per manual and the brakes worked great a few times then the pedal became hard right at the top again and the brakes started dragging. I removed the lines again and all was well.

I considered that the brake valve was leaking/bypassing internally building up pressure, but wrapping it in a bag and working the hoe shows no build-up of fluid so I don’t think the valve is leaking internally, looks like a spring loaded check ball would manage the return bleed and I can't imagine that it is seized, anything is possible....

I reviewed the manual and found there is an external brake piston adjustment, 3 screws in each axle housing and considered maybe he did replace the discs and there were too tight. Well, the screws in these axle housing are not at all like the manual, they are just short O-ring cap screws effectively that when removed allows the hydraulic oil to leak out, press the brake pedal on the corresponding side and it squirts fluid out properly so I'm barking up the right tree, but there is no adjustment pin and locknut here to set the piston internal clearance.

The axle fluid was nasty, on a lark I got the fluid hot and drained the axle oil thinking perhaps he had regular gear lube, it was quite thin so likely not but was black, smelly, and full of very fine metal powder.

I refilled with hy-gard and while the initial result seems better I still feel a drag when hot and believe as time allows me to use the machine the brakes will again lock up/seize.

So my questions are;

Does anyone from back in the day know why the brake piston adjustment screws are not what is listed in the manual?

Anyone have an idea about the brake drag?

Could the fine metal powder be an indication that the discs are shot and metal to metal and the drag is being created by that related to heat, or is this normal for an old machine with wet brakes?

Is there any way to inspect the brake condition without removal of the axle housing?

I’m not scared of fixing anything on this machine but time is limited and if it is down for repairs it is not being used. I have a decent amount of hoe work that I can do while I learn about this but will reach a point where I need the loader and with the terrain I have not having brakes will be unsafe.

 

[mg2361]

If your brakes drag when connected to the master cylinder and do not when disconnected then the master cylinder pedals need to be adjusted. See attachments.

 

[RGM161]

Those are the bolts that are not installed, this unit has plain cap screws with orings. I’m hoping to find an old jd tech that knows why and if they are something that can be converted, or need to be.

On the brake valve I need to study the adjustment bolts a bit more to understand what I’m doing but did not consider working with this adjustments, I will review thanks

 

[mg2361]

I am an old (and current) JD tech. Sounds like the service brake update kit was installed eliminating the brake retractor stop screws. See graphics below. Let me know if the hole size has been increased or not (3rd graphic). The easiest thing to check when checking if your master cylinder pedals are adjusted properly or not is to disconnect the lines to the brakes and you should have oil running out of the lines constantly (emptying the brake reservoir) and when you push the pedal down a 1/2" the oil coming out of the line should stop. OH, by the way...Welcome to HEF!

 

[LarryH]

I have a 310A and according to John Deere Parts the master cylinder for the 310C is identical to the 310A model. I have completely rebuilt the master cylinder on mine and had similar issues with it. It sounds like you need to adjust the pedal travel at the master cylinder. There is a certain procedure for doing that. If that doesn't help then the problem is probably internal to the master cylinder. There are pins and springs located inside (No. 12 & 13) in the illustration that must function correctly and be in adjustment with the plungers. Adjustment of the plungers is accomplished with the capscrews and jamb nuts (#18 & 19). The problem you are having is in the hydraulic system and most likely has nothing to do with the pads and disks. The 310A has no means for adjusting the actuators in the axles and I suspect the C model doesn't either. The hydraulic pressure is relieved in the system when the pedal and plunger are returned to the rest position. This is accomplished by the plunger #7 contacting the pin (#13) on return and tipping it slightly thus allowing fluid to return to the reservoir. If this doesn't happen then the system stays charged and the brakes will drag. The tech manual doesn't explain the system very well and I figured it out by trial and error. I hope this helps.

 

[RGM161]

Guys this is a huge help, mg awesome, now I understand the why of the adjusters and that feedback could only come from a tech, nothing in the net told me there was an update. I am not going to focus on the 5/16 hole yet as I can verify I am not getting oil dripping out the master cyl outlets.

Larryh, you confirmed the hydraulic circuits that I have traced out today trying to understand the why. Thanks. I am 100% now that overhauling the brake valve is time and money well spent.

Now, can either of you recommend where I can get an overhaul kit as a kit as opposed to going to the dealer and piecing it together.

 

[mg2361]

Google search Brake valve kit AT184432 ( Deere list $217.77) for s/n 747742 and up. AT184433 ( Deere list $290.38) for s/n 747741 and down.

 

[RGM161]

I need the 33 part number, x2 wow, didn’t expect that kind of price point

 

[Tags]

Welcome to HEF! I admire the fact that you're attacking this problem head on and not going after the seller who may or may not have "fixed" the brakes, even though it sounds like he needs a kick in the jewels.

Don't take this the wrong way, but if you think $290 and change is expensive to get your brakes in proper working order then you better hope you don't blow a hydraulic line or need a cylinder rebuilt....I do get that parts are expensive and we never really expect a simple rebuild kit or seal kit to be so much, but it always seems to end up that way....hope you get the brakes squared away.

 

[RGM161]

I bought a 35 year old piece of heavy duty construction equipment with 5084 hours on a broken hour meter. I’ve been in the auto industry since 1984, I have realistic expectations. I also run a Porsche service department, I get high dollar parts... stinker of it is it takes two kits to overhaul, $600 is steep. I had always head JD parts were lined with gold, I’m thrilled I get to experience it first hand!

And I’m thrilled to have picked this forum to join, I have spent weeks working and thinking on this problem,I was out of everything, in one weekend I learned everything I was stuck on and have a firm direction on a repair regardless of the cost. Not a bad use of the internet.

 

[LarryH]

RGM
The expensive kit you are referring to only consists of two pieces if I recall. That is the pin and a conical spring that holds the pin in place. Since I’m cheap, I ended up making two new pins from a grade eight bolt on the lathe. I had one good spring left to use as a pattern so wound two new ones also. It wasn’t that difficult and you can spend the money you save somewhere else on the machine. The only other parts you need are a couple O rings and seals on the plungers.

 

[mg2361]

I need the 33 part number, x2 wow, didn’t expect that kind of price point

That part (#33) is obsolete through Deere but can be found here https://www.vpartsinc.com/search?ma...Search=t122169&x=4&y=3&searchMode=starts_with

 

[Deon]

That part (#33) is obsolete through Deere but can be found here https://www.vpartsinc.com/search?ma...Search=t122169&x=4&y=3&searchMode=starts_with

RGM161, I have a 310D. I went through the same brake lockup situation you have. My master cylinder looks just like the ones in the photos above. The two pins LarryH has in the photos also look the same. It’s been a while but I’m quite sure those pins get damaged by installing them with the brake pedal in the up position. You need to hold the pedal down to install those pins. In my case, my brakes would start to drag and then stop the tractor after 10 minutes on the road. I remedied that by setting more play in the brake pedals. On mind it’s a very fine adjustment to get the pedals adgusted so they don’t drag and have brakes on the first apply. If too loose you need to pump the pedal and if too tight they drag and heat up the shoes and jam up. When adjusting, start loose and only turn the set bolt 1 flat at a time between test.
Like LarryH, I also built my pins on the lathe for just a few pennies.

 

[RGM161]

LOL, love you guys, so what you are saying is instead of $600 worth of JD parts I need to spin it to the wife as I spend $1000 on a decent small bench lathe, but of course that could save me $1000's over the next decade.

After 30 years she is quite used to these type proposals, this one might just fly!