2001 753G Bobcat, bought this when it was one year old, now has about 550 hours on machine. Spool valves leaking from rear. I've rebuilt auto trans many times over the last 40 years or so. Replaced the leaking spool valve orings. Used youtube vids as reference and correct service manuel for parts and instruction. took pix of spool valve "seal" direction before disassembly. All was working before replacing leaking spool seals.... service all filters and belts. Engine runs, wheels move, spool valves no longer leak.... but lift and tilt are frozen in the up position. All lights are on when running including the BICS light. One long beep when starting, no error code. Spool valve solenoids are unlocking.... Replaced the BICS stem valve and solenoid, verify by using the old valve with solenoid in my hand when engine running, I can feel the valve activate/de-activate when I slide solenoid off the stem valve. When pedals depressed the rams move about 1/2 to 1 inch, i can hear the engine load up, but I feel resistance like there is something blocking the hydraulic circuit ram circuit?????? I'm stumped???? anyone have any ideas??
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753G Bobcat 2001 no lift no tilt
- Thread starter lonfu
- Start date
main rams are fully extended and arms are raised with the safety lock in place. yes, pedals move, the spool valve lock solenoids are unlocked and the spool valves can be moved. when I try to lift the arms to free the safety lock or try to change the tilt angle, the rams move an inch or so and the motor boggs down. most of the hoses are stainless steel and difficult to switch. which ones would you suggest?
Only other thing that comes to mind is the BICS valve not releasing, this would cause it to act like that.
Sounds like you have verified the coil and stem are working, so would almost have to be internal, did you have any plugs/ springs/ shuttle valves etc out?
And not that I think you're confused. . . . but the Bics valve coil is the one in the middle on the side of the main valve, buried in the steel pipes. Bare stem is visible towards bottom of your second pic.
Sounds like you have verified the coil and stem are working, so would almost have to be internal, did you have any plugs/ springs/ shuttle valves etc out?
And not that I think you're confused. . . . but the Bics valve coil is the one in the middle on the side of the main valve, buried in the steel pipes. Bare stem is visible towards bottom of your second pic.
yes, thank you for responding. yes, I have the correct valve. on the valve body there are 5 electric solenoids. the center one is the BICS valve. Unless, I have totally flown the coop, it is the only stem valve that is on the valve body. because it works, both on the unit and off the unit is what throws me. ohms test good on the coil but I've bought both a new stem valve and solenoid. thought perhaps the old stem valve was clogged, but no it seems to be clear.
yes, thanks for responding.... any help is good help... So I went back out and reinspected my hose installation and just couldn't see any possible mixups.... I did not need to remove any of the stainless steel pipes. the only rubber hoses that I removed was the manual release valve but I left those in place so I would not mix them up. I did not need to remove the valve body, only rotate it in place so I could the extra long spool valves out! I have before pix and after pix and they look exactly the same... aren't digital pix fantastic!!!! these are the before pix and the after pix are exactly the same... can you see anything that I'm missing???
Attachments
The continuing story of my woe... so, replaced 9 year old batt thinking that low amperage could be the culprit, but no... still have problems. pulled out hydraulic schematic and none of my hoses seem to be cross connected. Ok, so turns out that the bics stem/solenoid valve controls the (bic's locking valve) the stem valve is the pilot valve that controls the actual valve that does the work. there are 2 Pilot operated valves, one in the tilt circuit and one in the lift circuit. both of these are controlled by the Stem valve and solenoid which allows a hydraulic valve to operate... So, I'm back where I started. logically it would seem since both are not working then the electronic control pilot valve is out? But no, I've tested the solenoid and stem valve. I can feel it activating out side the tractor. but I replaced them anyways. the only other things that are in the hydraulic circuit are these hydraulic operated valves that are controlled by the stem/solenoid valve.
spidermike
New Member
Reading this with much interest. I'm working on a 953 with fuel problem, luft cage and remove inline filter, dry,pull fuel sending unit and find suction line laying on bottom of tank.Getting new one tomorrow but running machine off jug with fuel to move inside and once I lowered cage and tried to move boom and tilt bucket things got weird. Goes up but not down with main and tilt will go down but not up and I didn't mess with any hydraulics.
yes, about 10 years ago I had that problem. the fuel pick up tube rotted off and fell to the bottom of the tank. 325 hours. At the time it made me suspect the quality of Bobcat parts. I left the pickup tube in the bottom of the tank and installed a new one. So far it has lasted 10 years with out problems. Now with all the leaks in the ram seals and spool valves, I'm beginning to believe that they have quality control problems in their parts department. Bought this unit when it was one year old, and have kept it stored inside it's entire life. It has 532 hours on the clock. sounds like your hydraulic valves have become clogged like mine. the electric solenoid on the BICS valve operates a stem valve much like a propane gas valve. This stem valve operates 2 hydraulic valves further down the line. these valves do not use electricity, but use hydraulic pressure to open and close. this pressure comes from the BICS stem solenoid valve. Service manual suggests that I replace the Oring set on both pilot operated (hydraulic controlled) high pressure valves. Bobcat seems to want $125 for one set of orings???? Are you kidding? Needless to say I am very disappointed in the quality of original Bobcat parts. I know that I will never buy another unit no matter how good the price.
spidermike
New Member
Hey what a "Dah" moment, talking to the service tech at dealer,he's perplexed for awhile then the light comes on! The aux lever is ingaged, that's your right hand forward reverse lever.move toward outside to engage and inside to release.
Huh???? not sure what you are writing about??? Pix???
You have a G Series, with the auxiliary controls on the right hand handle switches. Electrically controlled. Spidermikes post would only be revalant on the older machines with manual aux controlled by moving right stick in and out. If stuck on would definitly affect loader control.