4240 No Left Brake,update, next step

Ken11487

Member
4240 no left brake function update (Tim?)
to recap.  1978 4240 Quad 7000 hrs., pulls 8 row planter 100 hrs per yr. no heavy work. Some grain cart duty. Bought new in 78.
Late in spring work we lost function on the left brake.
As advised on here I capped the line from the pedals to the left brake and the pedals then had a firm press just like the a neighbours 4230. I figure the problem is in the rear end.

I wonder about the axle bearings as well so we jacked up the tractor with a dial indicator to measure axle radial play, got .003” play on left side and .007"  play on right, measured at the axle housing end . Right side shows slightly leaking seal.  Is there a spec for refurbishing the axle? Should this be addressed while we're in there.

So, now we remove the axle housing and inspect/replace the brake piston seals? Any tricky parts to watch for as we go??

Anything else to do while apart???

Any reason to suspect the opposite brake will need service soon??

I have the JD service manual and expect most of the work to be like my 4320 restoreation 8 yrs ago.
thx Ken
 
Rarely do the brake piston seal fail, you need to pull that finaly drive and beging the search,, you can mail if you want for help as you go..
 
Are those models using a rubber piston seal or something made of metal ? If rubber I'd sure replace them when in there. I had the ones in a 2440 go bad before.
 
So do you make a lot of tight left hand turns with the planter ? Just wondering if it could be worn out ?
 

Port output pressure ? The internal check valve balls, springs and seats can stick or fail. Will the brake operate if the pedal is pumped.
 
Also there is a chance that the bleed screw on that side got backed out a bit.. make sure it is seated,,in fact I have seen the 1/4" ball get lost out during a repair and there would be no brake on that side,,I am assuming that this has not been torn down since the failure started,,and when you capped the line the pedal felt normal,,,"and" there is no apparent leakage on the line from the valve to the final drive..
 
I had the right side brake on a 4020 that was slow to release. Put a pressure gauge on the pedal valve to make sure it was working which it was. I took the final drive off and took to the local deere dealer, we get along pretty well. Anyway we couldn't see any real obvious problems but went ahead and relined the pistons, put new axle seals in, reset the load on the axle bearings and I put new piston O-rings and backup rings in before putting the final drive on. Seemed to solve the problem even though nothing struck us a odd.
 
It was working fine one day and not the next.
Not a lot of hard turns either way, usually just slight brake pressure.
No activation even when pumped. If both pedals are pressed at the same time it seems like the bad brake drains pressure from the good one. We had to try to use only the good pedal to get through planting.
Bleed valve is tight with no leaks at it or in the line to the pedal.
With line capped pedal feels "normal". Tractor has been in the shed since it finished planting, handy we got a 4430 from my uncle for a spare tractor.

I wonder if there is enough hydraulic line to hook it up with the final drive open a few inches and look in to fins the leak?
Ken
 
You will have enough line but the pistons will pop out..., plus all your oil will be gone..
 
You could make a fixture that would lock the pads in place and attach an air hose to the line fitting,, would only be 150 or so psi, but that and a squirt bottle of soap and water may help Identify the leak..if it don't show up well..
 
Got the axle off today. Made fixtures for the pistons and applied air pressure to the hydraulic brake line port. Air and oil fog came out the axle shaft bearing hole. Air leak sounds came from inside the case. It could hold no pressure at all. Fished around a bit with the bore scope but haven't found it yet. Any ideas.?

Also five of six brake pads were loose and could slide back and fourth on the rivets. Any source for rivets and pad???? I hear they are NLA at Deere, but new back plates and probably pistons are available.

Can the rockshaft cover be removed with the cab on?

Ken
 
Also the axle shaft outer seal does not leak but the radial bearing play measured .003 to .004". Can I just tighten up the bearings to zero end play and have good radial play? I think the goal is .001" radial play?
Ken
 
Brake pads and rivets are still available,, and the leak still sounds like it's going through the bleed port,, remove the bleeder screw and make sure the ball is in there and make sure the screw is seating it,,Yes you can get the rockshaft off,, but the only thing that can leak into that area is the bleed circuit...,,and a cracked trans case...and we don't wanna think about that..as far as the end play it may tighten up enough to take that little bit out..
 
Aha, right again, Tim. Looks like the bleed valve was passing oil. I know we checked that last spring but I was the guy in the cab, not on the wrench. Anyway the leak is stopped, and the bearings and brakes need service.

The brake pads measure .110' thick. How thick are new pads?Deere shows only backing disk and piston plates with pads installed, pads only seem to be NLA.
I see A&I has pads and rivets that look the same.
Do you get pads and rivets from another source?

What kind of sealant do you put on the axle housing gasket? and do you use a goodly amount?
Ken
 
You didn't waste your time looking at the brakes,, Yes the new pads are made from a Cevalare type material, you can get them from Deere or A&I, pay attention to ordering the pads and rivets correlate your parts to the casting # on your plate, different size pads and different lengths of rivets, post the casting number off your plate and I will help you with it. And I will post a Hill billy way that I replace them...as for the gaskets I set them in place and it seems that I always need to trim them a bit so that they don't "Pucker in" as I slip it together, I use only sticky grease to hold it in place,, I have a bucket of Red grease here that is so sticky that it will follow you around all day... I was leaning to this being your problem from your first post...
 
A&I says their fiber pads replace my originals.

Just tried to measure end play with the axle housing hanging from the fork lift. Couldn't get any movement when tapping or lifting on the axle end. It must be fairly tight anyway. thinking of turning it by hand and tightening the bearings one setting and see how it feels. I did get .003' radial on thistle and.007' on the other one.

We have some Lucas Red & Tacky that is real sticky here.

Will work on the brakes.
Looking fwd the the 'Hill Billy' method.!
Ken
 
One of the reasons for gaining end play is the outer bearing works into the "Spacer" that is behind it on the axle, side to side thrust from use eventual wears into the spacer letting the bearing creep out a bit giving too much end play, there were 2 methods of torquing the axle bearing, one from just tightening to the correct torque the other is to tighten to shims,, if it's not so loose as your seems I would tighten it up more and go on with just servicing the brakes. I pull a lot of final drives here just to look at the brakes, most times all is okay but the only way of knowing for sure is to pull them and look...
 
Matched my brake back plate # R60116 to use 2593R and R708R rivets and piston plates to D1761R rivets.
Tested torquing up the special bolt, seemed like it was right, then removed axle from housing to refurbish seals. The outer seal was a bit brittle so felt it was time. I hope to just re-torque bearings to 170 ft.lb and reuse bearings which look real nice. Axle housing had a fair bit of oil in it and I don't like leaks!
Found inner seal at bearing dealer, shoes and rivets at A&I and the rest from Deere.

So Tim...What is the "Hill Billy" rivet method?

thx
Ken
 
I haven't forgot about you,, I got busy loading up a couple to return in the morning..What I do is drill an old steel top bench I have here using a pad for a template,then I drop some small hex head bolts into the holes (seems like these are 4.5mm), these bolt heads keep the rivet tight against the pad then I slip a new pad across from the pad I am doing to keep the housing level, I then use a bolt and a piece of metal to clamp the housing tight on the pad, then with a blunt punch peon the rivets. I thought I had an old housing here to show you better ,,but it's in the bottom of the scrap pile..but you can kinda see what I'm doing,, you need to keep the rivets tight on the new pad ( the bolt haeds0 ,,clamp the whole thing down firm,, and keep it level as you go. For the piston pads i have an old.Old (40's) foot operated rivet stand that works well for them, but the big housing won't fit into it..I some times ding the rivets a bit so that they stay in place when I flip the housing over to place it on the bench..
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Thx for the idea Tim, eyeing up my heavy bench right now.

Meanwhile we are changing the seal on the axle.
Do we have to remove the bearing to change the seal? How would we not damage the bearing. There seems to be a ridge about .005'to.010' higher than the seal seating surface, that the seal would have to slip over to go on from the outside . Don't remember this ridge from the 4320 tractor but it was bearings and all.
Ken
 
Dry the bearing off with some brake cleaner and a blow gun and warm it up with a heat gun, or a torch but keep the flame back a bit so you don't toast the bearing, replace the spacer that the seal rides on,, they take a beating and that is where your end play started..
 
I see the new spacer measures 15 mm, my old one appears to be 12 mm. Will this make a difference if so? Maybe new stock old stock thing.
Will this affect the bearing preload setup?
 
No it should be okay, just make sure the housing spins on the axle okay,, There is a procedure to set them up I can explain it over the phone if you want,, too much to type..Darn it.. 740-743-1085
 
It wears into the lip on the axle, taking the clearance away from the bearing set. call me tomorrow and i will fill you in...
 

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