Bobcat 853

Twankie said:
My miller the plastic spindle for the spool rides on a 5/8" steel shaft. Pull off the plastic and you can slip a 1-2# spool on. Is the Lincoln that much different?
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That was the first thing I tried. The metal shaft was too big to fit the spool on. Could have drilled it out, but since I do have a spool gun I figured i'd preserve it for when that gets set up.
 
Well, nobody's posted what the silver bullet is for excessive crankcase pressure, so this is what I've been up to:

Recall that the thing is puking engine oil out the dipstick tube, worse when revved up. Stops when valve cover oil fill plug is removed (obviously...).
No noticable smoke or mist coming from PCV tube or oil fill plug when removed (blow by isn't visually apparent).

Checked the PCV valve, looks fine, not plugged, ordered new one anyway.
Pulled the glow plugs and did compression test using a gas engine compression gauge that goes up to 250. All four cylinders buried the gauge.
I guess I could do a leakdown test, but don't have the setup for that, and can't find any friends that do either.
This engine isn't going to get thousands more hours on it, so I just want to limp it along for another few hundred.

My thoughts were to attach the PCV breather tube to the intake (currently it just vents to atmosphere) but then I read that since diesels don't have a butterfly to choke the air, they don't make intake vacuum, so that's not gonna help suck out the extra crank pressure.


I've found a part number for an auxilliary crankcase vent, and have found a spot on the crankcase that's cast like it's meant to be punched out and tapped for this extra vent. Engine starts and runs fine, even when very cold outside.


What's the next step (assuming the new PCV valve doesn't help).

Should I just cut the diaphram out of the old PCV and let the engine vent more? I think I'm mostly concerned with keeping the engine from puking out all it's oil when the dipstick leaves the chat.
 
Road draft tube.

But that seems excessive. Get a compression gauge that goes up high enough to get a real reading. If the cylinders had 250psi or less it might not even run.
 
If the engine was worn out you would be starting it from a can and it would be hazing all the time. Unless you have only one cyl bad, but you should hear the miss

I think you have a vent problem or overfilled oil. Ditch the pcv and just use a draft tube.
 
Dethmachinefab said:
If the engine was worn out you would be starting it from a can and it would be hazing all the time. Unless you have only one cyl bad, but you should hear the miss

I think you have a vent problem or overfilled oil. Ditch the pcv and just use a draft tube.
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Thanks! That's what I'll do.

It's not overfilled. I filled it by volume using the manual, and confirmed with the dipstick.

It's got a submerged dipstick tube, and the level is checked in the tube. This is where the issue lies, because the crank pressure pushes down on the oil, and it gets pushed up and out the dipstick tube.

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Got the chinkanese PCV valve installed, but reused the old spring because the new one (that came with the valve didn't fit:shaking:). Put it all back together and fired it up and it's no longer puking oil. Tried it cold at idle and cold half throttle and it's good. Tried it warm at idle and warm half throttle and it's good. Tried it warm at full throttle and it's good.

I'm speechless, but somehow the new rubber is slightly more flexible than the old???

Watched a few more youtube videos, and one suggested opening the oil fill cap when running and feel the air coming out. It should feel like a hairdryer. If you're feeling a pulse then you've got one cylinder bad (bad rings, hole in piston, etc). I did that and it felt fine.

Still have to find the radiator/hose coolant leak and weld up the hole I just found in the spark arrester drain plug.

I'm a happy lad.
 
Shoved a 2.4 through the garage door track and loosened the hydraulic cooler lines. Lifted and suspended the cooler so had access to the water rad.


Cleaned out all the schmoo and used the laproscopic camera to see the leak was from the upper area of the rad. Drained it and pulled it out. The brass (or copper or whatever rads are made from) on the side was worn through from the hydraulic line rubbing on it (line on the right side in the pic).

Sending it to the rad guy tomorrow for a fixup.

Also pulled the muffler again to weld closed the little drain plug on the bottom.

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I still haven't gotten around to adjusting the drive levers. Used it this weekend but it'd be a bit better and faster work if it drove right..

I'm not sure I have a good way of getting rear off ground. Unless a regular floor jack will lift it. My pos tractor is too small to lift it. I hated pulling trigger on it knowing it was smaller than what I wanted but it was a hell of deal.
 
NDCjeepsmith said:
I still haven't gotten around to adjusting the drive levers. Used it this weekend but it'd be a bit better and faster work if it drove right..

I'm not sure I have a good way of getting rear off ground. Unless a regular floor jack will lift it. My pos tractor is too small to lift it. I hated pulling trigger on it knowing it was smaller than what I wanted but it was a hell of deal.
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Drive the back wheels on some boards or anything to cheat a little bit, then put big cribbing blocks under the rear counterweight. Then use the bucket to push down, lifting the whole machine pivoting on the rear cribbing. Add more cribbing as needed to be safe and adjust the speeds.
 
Was wondering if bucket would travel enough to raise rear if I cribbed it. I know I can get front up that way.

I've got a few handfuls of railroad ties I cut into foot long sections for cribbing.
 
I need to figure out the Plan B method of getting this thing going if it stops in the bush.

My questions:

How to I turn on the fuel solenoid so cranking it will start it? I don't think it's got the big 'ol solenoid that pulls a lever to turn on the fuel that you can just hold open with a ty-rap.

How do I bypass the safety module so the boom will function even if the seat or cage bar safety proxy switches faily?

I haven't gotten into the brakes (park brake?). Do I need to worry about this thing fucking off down a steep hill while I'm driving it? I think that for it to freewheel downhill it needs to flow oil though the valves so I should be able to stop just by moving the hand levers to the middle...
 
Well, since nobody spoonfed me the answers to my questions, I got off my ass and found them myself. :flipoff2:

First pic is the mechanical fuel pump. The black thing beside the hose clamp is the "fuel shutoff solenoid" and when I unplug it the engine dies. So it needs 12 volts to keep running.
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Next pic is the boom/tilt function valve bank. One of those solenoids is the one that unlocks those functions. Still need to prove which one it is.
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Third pic, unknown solenoid pointing straight up from the chaincase. Guessing it's got something to do with brakes or park brakes. Still gotta get into that.
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I'm going to order a spare solenoid for both the fuel and functions, as well as a spare solenoid fuel pump. I don't think it's original to the machine, but helps once the mechanical fuel pump gets tired.
 
Muckin_Slusher said:
Well, since nobody spoonfed me the answers to my questions, I got off my ass and found them myself. :flipoff2:

First pic is the mechanical fuel pump. The black thing beside the hose clamp is the "fuel shutoff solenoid" and when I unplug it the engine dies. So it needs 12 volts to keep running.
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Next pic is the boom/tilt function valve bank. One of those solenoids is the one that unlocks those functions. Still need to prove which one it is.
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Third pic, unknown solenoid pointing straight up from the chaincase. Guessing it's got something to do with brakes or park brakes. Still gotta get into that.
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I'm going to order a spare solenoid for both the fuel and functions, as well as a spare solenoid fuel pump. I don't think it's original to the machine, but helps once the mechanical fuel pump gets tired.
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there's a black rubber plunger underneath the fuel solenoid, pull that out and reassemble and it'll run without 12v
you'll have to stall it to shut off though, I don't think that topcover has the manual shut off lever but you might be able to stall it out by backing out the idle screw all the way, dunno, just pinch off the intake hose

the one on the chaincase is indeed the parking brake wheel locky one, it has a high amperage "pull" coil and a low amperage "hold" coil, just like a starter solenoid, or a lot of fuel shutoff solenoids (the one on your injection pump only has the one coil)

the hydraulic function one will be easy enough to figure out which it is with a test light
 
Welded the new lip onto the bucket. Lip was a painted blade edge from an 8 foot truck plow. Not sure what kind of steel it is, but it's harder than mild.

Clamped two buckets together to force them straight during welding. I did this last time and the heat from the welding made the bucket take a set, and stayed straight after.

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Been driving this thing a bit lately.

Full throttle full speed on pavement will seriously fuck you up when you try to stop.

I know how to operate equipment, I know how to handle controls, but this thing is impossible to be smooth with.

Tomorrow I'm going to check the steering shocks. I assume that's the problem.
 
Muckin_Slusher said:
Been driving this thing a bit lately.

Full throttle full speed on pavement will seriously fuck you up when you try to stop.

I know how to operate equipment, I know how to handle controls, but this thing is impossible to be smooth with.

Tomorrow I'm going to check the steering shocks. I assume that's the problem.
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tighten your seatbelt and rest your forearms on the lap bar
removes a lot of the herky-jerky

kinda like bracing the side of your foot on the transmission tunnel while gas pedalling in a car
or just snapping the throttle hard to WOT then tapering back in a car with a very jerky clutch
 
[486] said:
tighten your seatbelt and rest your forearms on the lap bar
removes a lot of the herky-jerky

kinda like bracing the side of your foot on the transmission tunnel while gas pedalling in a car
or just snapping the throttle hard to WOT then tapering back in a car with a very jerky clutch
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Just lifted the cab, one steering damper is missing, broke the bracket and dissapeared.

Other is plumb worn out.

Ordering parts today, two dampers, and two rod ends.
 
I thinned a piece of 3/8 steel to 5/16 to weld on the steering bar to attach the damper. Did a real nice job, held in place and the tack didn't hold. No problem, I'm upside down needing three hands.

Set up again and tried another tack, still didn't hold.

Grabbed a magnet and, yep, the bobcat part is aluminum.:homer:

So I made a thing. I didn't want to drill yet another hole to further weaken the aluminum, so I welded a washer onto the shock bolt to help retain the thing. Seems rock solid, we'll see. The bigger hole is sized just right to fit over the existing nut on the other ball joint, so it can't slide off. If it doesn't hold I guess I'll set up my spool gun.

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Took her out for her maiden voyage on the Victoria Day weekend.

Got about 3 hours of popping out trees and moving sand. I was getting at those trees pretty good. Ended up blowing the gland end seal out the tilt cylinder. Had to disconnect the hose and put a cap on it to keep from continually losing fluid. Ratshit strapped the bucket up and drove it back to camp. I didn't put a cap on the cylinder side of the fitting I took apart.

Then I released the ratshit strap and let the bucket fall to the ground.

I look up and the whole fucking cab is dripping hydraulic fluid. The seat, the ceiling, the windows, everythiing, sprayed out the cylinder fitting I didn't cap. :lmao:

Anyway, I can now add "cylinder rebuilder" to my list of job's I can fumble through.

Got another set of tilt cylinder seals coming, as well as a couple lift cylinder kits. Might as well do them while this thing is back in the shop.

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Forgot to mention, I'm 100% happy with the goofy two tooth bucket, it's great for grubbing out trees and stumps, as well as stabbing and dragging trees.
 
Well I finally dove into it today.

My tiny pos tractor won't lift one end of a gutted Ford ranger so I improvised and put boxblade 1/2 way up, threw my trailer ramps on it and backed up it enough to slide two chunks of railroad tie under the rear. Front I just raised with bucket and did same with more RR tie to block it.

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Basically just did adjusting on neutral and it is way easier to drive.

Still creeps a tad and the right only goes 50% in forward but I noticed the horizontal linkage at valve has play in it so next step is new "shocks", cables, and springs/bushings at the valve.

The left valve is either sticking or the spring is wore out and doesn't have enough force to return to neutral.

Can stiction eliminator be ran in hydro to try and unstick stuff that moves but maybe not 100% freely?

I also bypassed the seat sensor by drilling out the center to 3/4" , doing away with the shoulder that it rests on the seat pin with and duct taped it in a spot that was seen by sensor. Which is roughly an 1/8" of full OD of white body showing after the neck down.

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:smokin:
 
Mine has a big old single spring that pushes onto a concave shape on the left and right steering (one spring for both). Because of this, if you have one stick pushed away from neutral, the other one loses it's spring centering. I think they did this so you can push both sticks forward, then just hold them both there as long as you're holding onto one stick (easier to pick your nose).

Also, the "shocks" end linkages are riding lawnmower steering ends. Mine was 3/8 fine thread X 3/8 fine thread, while most for sale are 3/8 X 5/16.

New shocks were amazing difference on mine.
 
So, the new shocks have made it much easier to control and be smooth while driving.

Just finishing up installing a winch on the boom of this thing after doing a job where we had to hand drag boulders and busted cement to the bucket (no way to turn as I was on a sidewalk beside a retaining wall.

I've got two lift cylinder hoses to change and would like to replace the clamp that holds the steel hardlines on the cylinder. Original was a bolt welded onto the cylinder.

Any issues with welding on a bolt without disassembling the cylinder? Will it hurt the chrome or cause issue with the fluid? Just talking about one small 5/16 or 3/8 bolt.
 
Muckin_Slusher said:
Any issues with welding on a bolt without disassembling the cylinder? Will it hurt the chrome or cause issue with the fluid? Just talking about one small 5/16 or 3/8 bolt.
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Welding to the body? No issue. Just make sure the cylinder is extended or retracted to get the important shit on the piston as far away as it can be.

I was always told to prop up the implement in question and hold the valve to that side of the cylinder open so that the oil has somewhere to expand to but that was in the context of repairing a mount and I don't think you need to do that for a simple bolt for a line clamp.
 
I would not weld to the cylinder, you will distort the bore if you really go at.
 
I'd be hesitant to weld to body also but a few tacks on a bolt isn't going to warm it much. Just don't go throwing a bead around it.
 
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