I have a 977l that quit steering altogether so I checked pressures and it was making pretty much 0 so that led me to replace the steering pump, after replacement I am still having the same issue which is the brake portion will stop the machine but if you press the left pedal to brake it stops both tracks and the right pedal does the same thing. I am at a loss any help would be appreciated. Thanks Noah
Are the peddles coming all the way back to the stops? If the bearings at the bottom of the peddles (older L's) get rusty you have to reach down and pull them back to get full drive power.
Yessir they are coming all the way back up, was steering fine one day then just quit with no signs of anything.
I'm guessing the clutch packs are good probably a control issue. I don't have any experience there. I'll take a look at the books tomorrow or Tuesday and get back to you. I need a little study time! Maybe someone else can help. Best of Luck
Please do follow up. Friend of mine has one of these on a farm and it's setting right where it ceased steering almost a year ago. I was going to put new chains and sprocket segments on it till this happened.
IIRC if apply the center brake it disrupts/bypasses the oil flow to steering on the Ls, if is sticking partially down may be dumping control oil. Strainers are a known issue for clogging on these as well.
See if you have pressure to the steering clutches when pedal is fully depressed
The stering cluch streaner should be block by some small brake band
Took a look. I'm stuck on what to would be a good next step so I barrowed a little help. Touch back and maybe things will work themselves out. Best of All the Luck
sounds like you have a blown steer clutch piston seal or two,one per side..there is a hydraulic piston behind the clutch that pushes the steer clutch in to steer..the foot pedal controls the steer valve on top of the rear housing,this valve sends trans oil to each side steer piston down inside the case to steer the loader.These seals ride on a shaft that has bearings that support the cross-shaft that the ring gear and input pinion gear from the transmission.When the bearings go bad they allow play in the shaft which takes out the steer seals and allows the steer pressure to leak past the seal and back into the case.When the oil gets cold sometimes the loader will steer due to the oil viscosity being thicker and it allows some steer pressure to the clutches then.When the oil warms up then it blows past the seals and you can't steer. You have to pull the whole back end of the machine off,(ROPS/Cab,fuel tank,operator station,hyd tank,etc) remove the top covers to the rear compartment,pull clutch packs and use the Cat hyd tooling to remove the clutch piston guide to change the seals,Better to replace the bearings too while you are in there.There was an bearing upgrade for this,we discussed it elsewhere on this page,Nige supplied the dealer upgrade info-awesome!) Anyway the piston presses on the tapered ends of the crossshaft with the Cat hyd Push/Pull tool,about 20T pressure to pull it off and reseat the piston guide back onto the shaft. Get qualified help and the proper tooling(Cat push/pull tool, and a 2-5/8"socket+drive for the shaft nut) or you will be doing it again. A 15/16 ratchet box end wrench makes getting the steer clutch mounting bolts out easy once you break em loose) My machine(977K) has the same issues I havent dug into it yet.) It sounds like your machine has the same problem.
Thank you all for the information. Haven’t made it back out to the machine in a bit but it does sound like I have a steering clutch piston issue.
to verify the clutch pack seals are leaking in the clutches. under the seat you'll see a valve body has two metal lines coming out of it going into the top of the cover to go down to the clutches loosen those two bolts and put a thin metal shim between them on both sides and bolt back together you can test the pressures now. at the top of each line is a plugged so you can plug in your gauges and check your pressures. If the pressures are good then your clutches are leaking If not it's most likely your boosters which had a habit of stick
Welcome aboard old cat mechanic! Always good to have someone New Help with these Old Treasures!