I am trying to figure out a problem with a D4 master clutch not disengaging immediately. I end up having to put a load on it for it to actually disengage, which isn't always convenient depending on what I'm doing, and it doesn't always take the same amount of time. Reading through the servicemans reference book I have from 1945, I have a couple ideas, but no real answers. the most obvious one to me is that there are supposed to be springs in the front pressure plate, that may not be springing.

There is no springs there to release but the rear metal plate my be hanging up and not releasing the pressure against the clutch disc. You should remove the inspection cover and work the clutch and see if you can pin point where it might be hanging up in there.

If it releases easier and faster when it's thoroughly warmed up, it's probably dirt, grease and gunk built up in the internal splines of the flywheel and is holding the clutch plate. You might try giving it a diesel rinse before you go any further. Shut the engine off after it's warmed up , and dump a couple of gallons of diesel in the clutch housing, put the lid back on and restart the engine. Then just engage and release the clutch for a while at an idle. .hopefully this will loosen and remove the gunk. Then drain it and dump some kerosene or solvent in and repeat. .drain it again and leave the top cover off and drain plug out with the clutch disengaged and let it evaporate for a day or two.

This might not be the "proper" way to do this but I had the same problem on a D2 and that was how I cured it. Hopefully, this will solve your problem too.

As Olielulu mentions, there are three sets of pins w/springs to assist in releasing the clutch. I've often wondered how effective they are as they seem pretty wimpy and in some cases froze up in the compressed position.
I would tend to agree that crud/rust etc. is more likely the culprit as most these parts are pretty loose fit when assembled clean.

Thanks for the info. After talking with one of the service techs at the Cat dealer out here, he also mentioned the rust/lack of lubrication on the clutch. I ran it with diesel to clean it out the other day when I initially started looking at it. so maybe when I go back up there it will be "magically" working again.
I did have the inspection cover open and watched the mechanism operating, but that was before I looked into the book or really new what to look for. I was hoping for something very obvious.
The tech at the Cat dealer did say that the springs on the front clutch plate are fairly useless, and only provide minimal assistance with releasing.
Talking with my father-in-law (owner of the cat) he doesn't remember ever oiling the mechanism (or doing any other routine lubricating) so I am going to look at it tomorrow and see what I find now that I know what I'm looking for.

Thanks again for the info, and I'll let you know what I find out.

The must lube items are oil for the clutch release bearing and the occasional greasing of the pilot bearing.

I think those springs in the clutch are just to keep the plate from rattling when it's disengaged. They're pretty easy to compress with just finger pressure so as far as helping to disengage the clutch itself, they're just about useless.

If your outlaw didn't do any greasing/ oiling etc during the time he had it, I'd say there's your problem right there. .rust and dirt buildup. I'd go with a diesel rinse. .it might take several days and several rinses to get it all loosened up and worked out.

Well, I went up and looked at the clutch today and the diesel wash helped quite a bit, but it was still not releasing. I ended up adjusting the clutch after looking at it and realizing that when I pushed the lever to release the clutch, it was not moving the mechanism all the way to the brake. I ended up taking up almost a half an inch of adjustment before it operated properly.
I put some degreaser on the clutch and pressure washed it, and will be testing it again in a couple days after it dries out to see how it operates and possibly adjust it to where he feels comfortable with it.

Thank you to all of you that have given me a good direction to go.

I hope that does the trick. .these old Cats are fairly high maintenance critters. To keep 'em running and working properly does take quite a bit of work keeping everything adjusted and lubricated.

You might get your outlaw a grease gun and oil can for Father's day. .