Long time lurker.. first time posting. I have an issue with the tilt not holding on my 773G. It only has about 1300 hours and is used around the farm. I've owned it for 5 years and only had to do minor maintenance on it in the past. The lift holds solid with no drift but the tilt bucket drops fast enough to watch the decline. There isn't any leak that I can find and it doesn't matter whether it's running or not. Just drops faster with a load. I just put in new spool seals (very thankful for willie59's guide) and new seals in the tilt cylinder (I had already did the other cylinder a few weeks earlier) and I'm not sure which could be the issue. I thought it was something with the spool seals I put in since it dropped so quickly and the other cylinder wasn't touched on the tilt. I wouldn't think with 2 cylinders on the tilt it would drop so fast if it was the new seals on the tilt so I took the spool seals out and inspected those again today and everything looks good from what I could tell. Also no leak around that area as well. Could it be a problem with the one cylinder with oil getting by to drop that fast or I have some bigger issue? :Banghead I guess I can take the cylinder apart to see if anything inside is messed up but I'm hoping someone can give me a little guidance to prevent me from messing something else up. This kind of work isn't my day job and I just piddle on the side for enjoyment.
i'd pull both tilt rods check the piston seals and make sure the piston nut is tight. :drinkup
I'll give that a try this week. Appreciate the help.
Well crewchief, I finally got a chance this past weekend to pull the cylinder back apart and check the piston nut on each one. Both were tight (I even tried to tighten them more and couldn't) and the seals all look good. I looked for any visible leaks again and didn't see anything. So... any other ideas to check?
Does the bucket tilt drift down just the same if the lap bar is up?
Yeah, it seems to drift the same either up or down. It just drifts much faster with weight in the bucket or forks.
Hmm, curious indeed. The reason I asked that is the bucket tilt circuit has a relief valve in the control valve for the rod side of the cylinder. A fault with that relief valve could cause the bucket to tilt down with a load. However, if the lap bar is up the BICS lock valve blocks the circuit to the relief valve, locks the oil in the circuit going to the cylinder. If it still drifts down with the lap bar up (BICS locked out), seems to still indicate a problem with one of the cylinders. Let's try this, stack two 6x6 blocks on the floor. Load your bucket. Lift the loader arms a bit and drive to the blocks. Of course with it drifting down from the load you'll have to work the pedal to keep the bucket tilted up fully. Once you get to the blocks, drop your loader arms to rest the cutting edge of the bucket on the blocks and relieve the load on the bucket. Shut the machine down. Now, disconnect the hydraulic lines going to the rod side of both tilt cylinders, use proper JIC plugs/caps to cap off the open hose fittings and cylinder fittings. Once you get the hoses and fittings at the rod side of both tilt cylinder plugged and capped, start the machine and lift the loader arms to lift the bucket off of the blocks. If the bucket now still tilts down, problem with at least one of the tilt cylinders. It it doesn't, I'm back to scratching my head.
Actually, the more I think about it, it would probably be better to plug/cap the connection where the rod side supply line Tee's off and goes to both of the tilt cylinders.
i wonder if the bolt that holds the centering spring is loose, or the tilt bonnet is loose..... :beatsme :drinkup
I'll try the plugging/capping of the cylinder and lines tomorrow hopefully. Got rain this afternoon. Appreciate the help as it def has me scratching my head as well.
I plugged and capped the connection for both cylinders like you said and it doesn't drop at all. I left the arms up for about 4 hours and no droop. I then tested out each side by itself leaving one side capped and the other hooked up just being curious and neither side had any dropping. So I'm guessing it must be back in the pump instead of the cylinders right?
What/where is the tilt bonnet exactly? I'm not familiar with that but will check try anything at this point.
the aluminum "cap" on the back of the control valve. it's held on by 2 allen bolts. if its loose, the spool can move slightly to the rear, causing a cyl drift. when the TILT bonnet is removed, you can access the retainer (allen head) bolt that keeps the spring tensioned properly. LIFT bonnet is longer and contains the detent springs :drinkup
................. I realize that this is an older post, but the way to check this problem out is THIS: DON'T GET STUPID AND TRY THIS ALONE. HAVE SOMEONE HELP YOU WITH THE WRENCH WORK!!!! Raise the loader's boom. STAY INSIDE THE LOADER and have someone else remove the top "down" hoses on the boom cylinders one at a time. If you see hydraulic fluid coming out of the hose the cylinder is bypassing internally and needs to be rebuilt. If it's not bypassing you have another problem - most likely a control valve or pressure regulator. I've had both problems happen to various skid loaders I've owned.
Well..I had a major delay as I had to have knee surgery and have been completely out of commission. The 2 micro-fractures in my knee were actually as frustrating as this bobcat is here lately. I started checking the tilt issue again and then the push to operate light was going off every few seconds. I went and purchased a new switch. I originally put everything back in the lap bar but couldn't get the light to stay on. Hooked it up by itself by just taping the magnet in place at first and it worked at first. It then started kicking off very often. So....back to the dealer to purchase a new magnet and bushing. Talked to the main mechanic about the seat bar and the tilt issue. He said the seat bar should be good to go with the new parts and he said the tilt sounded like the aluminum cap wasn't aligned correctly or had something catching the spring. Told me to take it off and check for any burrs inside and then put it all back together. WELL...this is where I have really put myself in a pickle. I took the first cap off and didn't really see anything out of the norm...so I decided to just take the other off and check it .....WRONG THING TO DO! I forgot about the detent spring and ball bearings.:Banghead. I had everything clean below so was able to find the spring and ball bearings. Now I need to take the spool back out to get the spring and bearings back in. Problem 1: I can't get the push to operate light to come on at all now. All new switch, magnet and bushing doesn't fix it. Checked the voltage on each wire. 2.39 volts , 2.53 volts and 0 volts on the 3rd wire. Checked and cleaned the connectors. Checked the wires for breaks or shorts...can't find anything. Over the last week I'll get it to come on, then can't get it to stay on...even when I wasn't moving. Problem 2: Without getting the PTO light on, I can't get the spools out...can't get the spring and ball bearings back in. Needless to say...I'm stuck! I do believe it may be time to sell my bobcat....lol. I have some other equipment and I've never dealt with anything as frustrating as this thing.
Anyone got any ideas on what to try with the seat bar safety switch? Grasping at straws now.