Hello: New to this forum and new to skid steer machines. I'm a small time farmer with a small 16 hp tractor with front end loader witch leaves me with the feeling of wanting more. I thought I'd like, one of them there Bobcats. Keep my eyes open for one and finally found one I could buy(that be cheap). Which brings me to this repair forum. What I got is a 853 with 8200 hr on her(thats what the meter says, who knows),the motor has newer rebuild. Lots to fix here, but before I get into all that can someone tell me anything about the ser. number, is there anything to be learn from it. (ser. # 512816692 ) Also is $75.00 the going rate for a service manual and best place to get one. Ok back to the one thing keeping me from digging in the dirt. The 3/8" plate steel lugs that the tilt cylinder attach to on the boom are gone (not the lugs on the bobtach,I think that's what you call it). I'm going to scab on some new steel plate for the rod end bore. My question is where to place the bore, with the rod all the way in should there be a gap between the bobtach and the loader arms (and how much if any) or is it right up next to the arms. I would think a gap but I do not know. Any how this will get me started , thanks for any help you can give and God bless America
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I would work on about 1/2", thats what i did for mine, you want it as far back as possible to give as much back tilt as you can. The manual price is about rite, there is a guy on e-bay that sells them, some dealers have them for very close to the same price! so call your dealer too.
You will find your machine is a mid to late 90's
You will find your machine is a mid to late 90's
skidsteer.ca
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If the locking levers on the bobtach don't look all bent and twisted, then unlock them so the levers point straight up, and with the cylinder fully retracted the levers should almost touch the loader boom crossmember.
I don't have mine here right now or I'd go measure somehow, but I can tell you I should have had mine a hair further back because when I got to lift the backhoe of the hooks on each side of the machine, I can't quite roll it back enough. I ended up taking the grinder and trimming the hook about 1/4"
Ken
I don't have mine here right now or I'd go measure somehow, but I can tell you I should have had mine a hair further back because when I got to lift the backhoe of the hooks on each side of the machine, I can't quite roll it back enough. I ended up taking the grinder and trimming the hook about 1/4"
Ken
Exactly, you want it as far back as possible, not just for a hoe but if you use forks you need to be able to tilt as far back as possible. The only thing you may have a problem with when you make the gap real tight is as the pins wear a bit the bobtach will touch the arms every so often causing you to rub the paint off. This is also due to slight flex in the bobtach, its nothing to worry about but just keep it in mind.
Ok, I got the plates for the cylinder end mounted on the machine. I used six 3/8 grade 8 bolts on each side, do you think that do the job. I was thinking it could be welded if need be, but will wait to see how things work before I do. Is there a procedure for hooking the hyd. lines, do they need to bleed or something or do you just hook them up and drive on. What about the hyd. oil, I'm sure it will need some but don't know what's in it now. Can I mix and match different kinds of oil, or is there a -one fits all- oil I can use. Thanks for all your help and will see what happens next!
skidsteer.ca
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You will need to weld the cylinder mount, the bolts will be ok for testing it and thats about all.
Hook up the lines, add oil so the reservoir is full and fire her up, cycle the functions back mand forth a few tmes to get the air out and back to the tank. Top tank back up. 10/30 motor oil or a simular grade of hydraulic oil is fine, unless your in a real cold climate and you plan on starting it in sib freezing weather.
When you get a chance check the big 3v or 4v belt that drives the pumps for tension, cracks and wear.
Also under the cab is a aluminum angle drive gear box that runs the engines fan off a single v belt. Check the oil level in the gear box case,
In the front center of the machine above to tie down loop is another plug to check the level and condition of the chain case oil. This oil often get water contamination from the covers on top of the chain case leaking. Look for milky colored oil.
The 853 are a fairly bullet proof loader, but at 8k hours let hope not all of them were hard ones.
Being new to loader repair and me without a manual, I was wondering about normal operation of the hyd. system. After replacing the tilt cyl. and running it back and forth about five or ten times, I noticed something like a foam in the hyd. tank (that there don't look right). Now is that just air being purged out after the cyl. replacement or is that normal anytime or is it something else? I will say that the tank is low on fluid though, I put five qt in before replacing the cyl. I'll get some more oil and top it off, and see if that makes a difference. How low dose the tank have to get before the hyd system starts to act up. Anyhow I'm off to the store to get some oil, have a good one and I'll talk to you later.
skidsteer.ca
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Foam is not normal during normal operation, but it is normal after opening up the system, when oil runs out, air gets in. You fix the leak and the air is trapped inside and has to work its way to the oil tank and rise to the top.
If the tank gets to low you will hear the noise as the pumps suck in air and feel the lift, tilt or wheels surges and skip as the air goes though. That is the sound and feel of parts headed towards a early grave.
Lowering the pressure in the sytem reduces the destructive force. Don't push things if you think air is in the sytem, best is to jack the machine off the ground (next best a leisurely drive on flat ground) and run the wheel under no load, then the pressure is at its lowest while the air is working its way back to the tank
Same is true for the lift and tilt, reduce the work it must do to move, remove the bucket, don't bottom the cylinders out as this forces the pump pressure to maximum. Just cycle thing back and for 95% of the stroke and the air will work out.
If it does not quit foaming after 2 or 3 cycle and rest periods (to let the air rise out of the oil in the tank) then you have other problems.
Ken
Good news, bad news on my quest for a Bobcat in working condition. Good news first, the repair on the tilt cyl. is done and seams to be working fine, although I'm still waiting to see if the air in hyd. oil will go away. Bad news, I go to start the loader up and the battery is low and won't start. Turns out that the water pump pulley(same belt turns the alt.,thus the dead battery) is split down the middle half way around and leaning to one side like the shaft is bent or broken. All I have done is look at so far, but I know I'll need a pulley and most likely a new water pump. Any help on part numbers and where to get them would be great. Also, is the water pump replacement about the same as on a car or truck or is there more to it then that. Thanks again and off to work I go.
Had to put the bobcat repair on hold till I could get some other concerns taken care of, but now I'm back to work on it. The water pump problem I had was that the shaft on the water pump was broken in two places. Then what happen ( my best guess) is the pulley fell down and spun on the housing, still being driven by the belt. The pulley wore away at the housing till it hit a bolt head then the bolt cut into the pulley till it split in half, that's when the belt got loose enough to stop spinning the alt. and let the battery go dead. Who know how long that went on for, you would think it would have made a racket of some kind for somebody to notice, but I guess not. Any how, I called bobcat dealer for the parts. 1) water pump 307.00 2) pulley 35.00 3) o ring for pump 7.00 ------ plus tax and shipping (not in stock). No way I'm paying that. Ended up getting the parts at a Isuzu motor rebuilder 1) water pump 189.00 2) pulley 21.00 3) o ring, came with water pump---- no tax, 12.00 shipping, that's better. I got the parts about 3 weeks ago and got them put in yesterday. Still need some antifreeze to finish the job. Then I'll see what else needs fixing before I can get some work done
skidsteer.ca
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Yes you want to go to the engine mfg for engine parts. I learned that on the water pump too.
If I had known you could wear them out that far, I should have run mine anoth 500 hours, it was just starting to leak a little coolant out the seal!
Ken
Sure is! i get all my engine parts from my local Kubota dealer. They handle after market parts too that sure help on cost, the quality is just as good.
Thats an awful lot of damage! i never would have thought you could have that much power through a belt to do that much damage!. Glad you got it all sorted out though.
The water pump is up and running. But as I was looking for a water leak I noticed a different kind of leak. Looks like fuel seeping out from behind a football shaped plate held on by two bolts on the injector pump (see pic). Can someone tell me if I can just remove this plate and reseal it or is there something behind this plate I need to be concerned about, like a spring or high pressure fuel or something else. Thanks for your help.
mllud
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Im not sure your if your talking about the lower one or the one on the side. I have been working in my pump. I have a different brand. on mine the upper plate is just a cover. In some applications there would be a fitting where that little circle is in the center. I would feel fairly safe in removing and resealing that one. The lower one i dont know. Being flat as it is it looks to be just a cover. What ever you do , if you seal it be sure you use a sealer that is compatable with diesel fuel.Use any sealer modestly. any excess sealer that squezes to the inside could get loose and get into your injectors or internal valves. a gasket only would be best. check the bolts maybe theryr loose. Wisful thinking. Mike
skidsteer.ca
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You would have to talk to a injection pump shop to know whats under there. Us mortals don't normally touch them. But I'm sure you can reseal that plate ok. Just use care as Mike said.
Seen as you just made a donation to Isuzu, you could perhaps ask them.
I can't see how that cover could be retaining anything too difficult.
The Bobcat 853 manual only show removing the pump and timing it.
Ken
I still don't know what's under that football shaped plate (lower shape in the pics, earlier post ), but I'll worry about that later. I think I may have found another problem or sub par repair, the engine mount on the right rear doesn't look right. It has a square nut that looks like it slid out from it's mount. A easy fix I thought, just slide it back in and good to go. I should know better on this Bobcat. That area is so worn or that's not the right set up, that square peg don't fit that round hole. My question is, is that square nut right or is their a barrel nut or something else that secures the motor mount.-- 2 nd pic. is that the crankcase oil fill. Just want to make sure before I dump in two gallon of oil.
The square nut is correct, on mine it was like that so you didn't need to use a spanner on it as it was large enough to not move inside where it sat. I hope that makes some sense.... But yes, yours looks very wrong, it shouldn't be sitting at that angle. It looks like it has been rattling around a bit.
skidsteer.ca
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Yep thats the engine oil fill, mine also has on on top of the valve cover but good luck getting anything in it.
Ken
I just had another look at the engine mount, it looks like the bottom of the housing has broken off? Hopefully its just the way i'm looking at it. Even if it is broken, i'm sure you can work out something to make it hold down tight.
