Cat track loader purchase

[ippielb]

Molded plastic of Fiberglass?

the roof is made out of molded plastic, so I repaired everything I could with the plastic welder. But the hole that’s left I wasn’t able to find the plastic pieces, so I’m going to try and fill it with fibreglass. You can visually see the hole from in the cab it would absolutely drive me up the wall if I left it.

 

[DMiller]

Would Rough glass it on the underside, then finish it on the top side to keep from developing a low spot water puddle leak point as it will eventually break loose.

 

[ippielb]

Would Rough glass it on the underside, then finish it on the top side to keep from developing a low spot water puddle leak point as it will eventually break loose.

Yeah, i was watching some videos on youtube, some people have put tinfoil tape on the visible side, and then fibreglass on the inside. then finished it with some body filler on the top. I'll probably try that method. I have some CAT yellow paint as well i can cover it to make it look half decent. I'll have to try and seal all the other cracks with some as well or else if the water can get in it will just crack it more.

 

[ippielb]

Time to do some maintenance on the loader. I have to repack one of the tilt cylinders. Got a quote from CAT for $2,400. Looked at the quote. $350 for the parts, the rest is labour, honing, and polishing.

I haven’t rebuilt a cylinder on a piece of heavy equipment before but I have on smaller farm implements and a power trim tilt cylinder on a boat.

My biggest concern is getting the rod nut loose And back tight. I don’t know the torque spec on them.

Now, I have all fresh hydraulic fluid ready to change all the hydraulic oil when I’m done. But I want to do one of the lower lift cylinders as well because I see it is starting to leak a bit.

Should I just support the bucket in the air and remove both cylinders at the same time?

 

[Welder Dave]

I wouldn't be surprised in the cylinder nut/bolt is 1200 ft./lbs. or more on a 973. Depending if the cylinders appear to be in good shape, you may be able to just take the rods out and have a shop change the seals for you. Cat cylinders are a lot different than farm implement cylinders. If the machine is your primary money maker get the cylinders completely rebuilt. If the machine isn't used daily to earn a living with then you can probably get away with just changing the seals if the rod and barrel look in good shape. Cat will want to do a complete overhaul and pressure test the cylinders so they can be warrantied. Just having the seals changed won't have warranty if they leak but will be substantially less expensive so is a bit of a gamble. It would be the same if you did the seals yourself but they would have all the proper tooling and know-how to put the seals in and tighten the piston nut/bolt. I just had the seals changed on my 931B 4 in 1 bucket without any problems. Seals were about $100 per cylinder and they charged me an hour labour each to change them. This is taking just the rods to them. The tilt cylinders I took in complete and they cost $1750 to have both done but they said the chrome was bad and they had a slight bend. I'm not sure what all is involved with the quote you got from Cat or if that is just a rough estimate until they actually see the cylinder(s)? I also think some hyd. shops are no different than some automotive shops that tell you need stuff done that you don't. In the future if I take a cylinder in I want them to show me what all is bad other than the seals instead of just taking their word for it.

 

[Nige]

I wouldn't be surprised in the cylinder nut/bolt is 1200 ft./lbs. or more on a 973.

Off by a factor of 100% - it's actually 2300 ft.lbs.

Should I just support the bucket in the air and remove both cylinders at the same time?

With something of the size of a 973 you need to make double sure that everything is supported correctly if you plan on removing multiple cylinders at the same time.
https://www.heavyequipmentforums.com/threads/bobcat-arms-fall-accident.85537/

 

[Welder Dave]

I was going to say 2000 ft./lbs. but I knew they'd be ungodly tight. I think you'd pretty much have to have a cylinder bench to loosen and tighten them properly.

 

[DMiller]

As heavy as that loader frame is, I would DROP the bucket if at all possible then set a STEEL Frame to support off the pivot bores to pull Both at same time, and YES takes a puller to remove the bucket pins.

 

[Nige]

.....and YES takes a puller to remove the bucket pins.

Not exactly. The bucket has collet-type pins so they use three fine-thread extractor bolts. The problem is usually that no-one plugs the extractor bolt holes and so when you want to use them they are either blocked up with crud or the threads are corroded, or both. Bearing that in mind I'd vote to leave the bucket on.

 

[ippielb]

The quote for the tilt cylinder was $2,400, and it was a repack, hone the bore and polish the rod. $1,400 was labour.

I had a feeling the cylinders would be quite different from any farm cylinder I’ve done.

I do not want to remove the bucket not w standard pin as Nige said.

I was going to take a round bale Or two side by side under the pins on the bucket and let the bucket rest on the bale at the heel of the bucket so it can’t roll back.

the next issue. The rear tilt pin is only removable when the loader arms are down because the pin removes to the outside of the machine. And with the loader arms up it blocks the pin from being removed.

I was hoping I could remove the tilt cylinder pin, and the oil is not transferable between cylinders When under pressure so one could just support the loose cylinder and then lift the bucket on the bale to remove the lift cylinder.

 

[Welder Dave]

Looking at a pic. of a 973 you may be able to lift the boom enough to retract the lift cylinder enough to get it out and also be able to remove the pin for tilt cylinder. The other thought I had but not sure if it's possible is leave the bucket down to pull the pin from the tilt cylinder and then put the pin back in (or another temporary pin) from the inside just so you can lift the boom enough to get the lift cylinder out. I think you only need to lift the boom a foot or so to have enough room to get the retracted boom cylinder off. It wouldn't have to be way up in the air and you could use proper blocking to hold the boom up.

 

[DMiller]

Am thinking the Lift cylinder will drop at the front enough to slip forward and out Boom Down and solid. Just have to situate lifting mechanisms appropriately. MUCH Safer than balancing acts with the boom Up.

 

[Cmark]

Personally, I would do them as two separate jobs. Tilt cylinder first, then lift cyl. Lifting the loader with a tilt cylinder removed is going to cause you all sorts of trouble getting it back together, along with oil loss unless you get creative with blocking plates for the hoses.

And don't underestimate the removal of the lift cylinder head-end pins. Approach the job with the attitude that you may have to pull the rod out and leave the barrel in the machine.

 

[DMiller]

If that is the case place bucket in dump position sit teeth on a piece of steel to keep from settling into soft soil then pull pins for lift Cylinder

 

[ippielb]

So I opted to do the jobs separate. I didn’t want to risk any kind of accident.

took the cylinder off today, which wasn’t an issue at all, heavy SOB though, used the tractor and put it on a pallet.

found a local guy that use to work for CAT as the head hydraulic specialist. Dropped the cylinder off at his shop he has a cylinder bench to rebuild them on.

right away he got me the cylinder number off the cylinder to take to cat and then I’ll go get the seals for him, he grabbed the rod and spun it by hand and he said the cylinder bore might have to be taken in to get honed because he doesn’t do that.

said he could rebuild the cylinder for half of the quote. So let’s see how it works out. If that’s the case then I can afford And justify to get the two lift cylinders done as well while I’m at it. Get them out of the way so hopefully I don’t have to open the hydraulic system again.

the part that is crossing my mind is if I should be getting rubber o rings to fit around the pins to take up the slack side to side on the cylinders when installed.

 

[Welder Dave]

There were wiper seals on the ends of the cylinder eyes and if I recall shims on the barrel end on my 931B.

 

[Nige]

The 973C linkage doesn't call for any sort of shims on the cylinder pins either lift or tilt.
All the cylinders should have wirper seals to act as relief valves for grease in the joint (see illustration - Item 5). Replacing them should be part of your cylinder rebuild. Make sure the lips face outwards as per the illustration.
Rubber O-Rings in the gaps wouldn't do diddly squat as regards taking up play. Even if the linkage was well-greased they would tear up and fall out in short order so IMHO you are wasting your time with that idea.
Also bear in mind that where linkages are concerned they need some sideways float to compensate for any misalignment that there might be. The only pins that really need to be shimmed to reduce side float to zero (or almost) are those between the Lift Arm and the loader frame (circled). Any play there and with a full bucket up in the air effectively you have a 20-ton hammer banging from side to side. That's what cracks things.

 

[CM1995]

FWIW the only shims on my 953C BBX series is from arm to bucket pins. 2 years ago had the Cat house replace P&B's on the bucket and tilt dogbone as well as repack two cylinders. They re-shimmed the bucket pins as well.

 

[ippielb]

I do have side to side play in that spot you mentioned. There is no shims there at all. Does one buy special thrust shims or just use any shim will do?

The hydraulic guy I dropped off the cylinder to last night tore it apart this morning and called me to let me know he’d recommend a rod polish. So I went and picked up the rod and I’ll be taking it in to get polished. The barrel crosshatching was just fine.

the seals were completely worn out he also said, after 20 years of use I think it did well.

 

[Nige]

The Parts Manual doesn’t list any shims there. Right where the pin marked F-F is, measure how much space you have between the outside surface of the lift arm and the inside surface of the machine frame on both sides and post the measurements.

Probably be something like 5-15mm on each side