1973 CAT 930A wont budge

[Seans problems]

This thing was parked about a year ago from what I hear and they dispatch it the other day. The operator goes to start it and nothing happens, Okay. Jump the batteries after I checked them and this thing turns right over and starts. I put the jump box back and operator says he shut it off by accident and it needs jumped again. Simple enough, I hook up the cables and have him turn it over but I get nothing. Poop. I test for power and the starter has it but it just quit on me. I need a day to get this one rebuilt because no one has this style in stock near me. So I put the batteries on charge and go about my other broken chores.

I got the starter back and slapped it in along with the batteries and it starts right up now but even after building pressure in the tanks it wont go in any gear, reverse or forward.
It shifts fine but it seems like the parking brakes are holding it up but they open and close Like I believe they should.
Do you guys have any tips or tricks to free this thing up?

 

[kshansen]

You say it shifts fine, I'm not there so a little more explanation of what that means would help. Does the lever move but you don't hear or feel the engine come under any kind of load? Does it sort of jump a little when shifted say from forward to reverse?

Actually probably the first thing that would help is a serial number or at the least a prefix like 41K, 71H, 73U, 79J a complete number would be best!

Do the foot brake peddles work nice and free, especially the left one? Believe there is a line from the left peddle to the transmission that if it has any air pressure in it from a sticky brake valve will hold transmission in neutral.

If this has been parked with parking brake on for a year it is possible that the shoes are stuck to the drum with rust. You could try chocking the wheels so it can roll then with parking brake released and motor off give the parking brake drum a wake-up call with a big hammer and try moving it again.

Just be careful as if the parking brake does pop free there could be damage to the shoes and it may not hold after it's free.

Good Luck, work safe!

 

[Seans problems]

Hey kshansen,
Thanks for the reply.
The transmission shifts into forward and reverse and lurches forward or backward (depending on what you put it in) about a half inch. the peddles are free and don't feel stuck to me. I thought about the hammer time method but figured I'd wait for you guys to give me some ideas. The only other thing I can think of is that since it was parked on a decline the fluid may be low. I don't have a manual for it to tell me what kind goes in. I'm guessing here in Washington it'd be 15w40.

The serial number for this one is :41K4480

Thanks again,
Sean

 

[kshansen]

Hey kshansen,
Thanks for the reply.
The transmission shifts into forward and reverse and lurches forward or backward (depending on what you put it in) about a half inch. the peddles are free and don't feel stuck to me. I thought about the hammer time method but figured I'd wait for you guys to give me some ideas. The only other thing I can think of is that since it was parked on a decline the fluid may be low. I don't have a manual for it to tell me what kind goes in. I'm guessing here in Washington it'd be 15w40.

The serial number for this one is :41K4480

Thanks again,
Sean

Not sure which "fluid" you are thinking might be low. Have you checked the transmission oil level?

If it is lurching when shifted into both forward and reverse, kind of sounds like the parking brake is stuck. Have you tried giving it some throttle to see if it will move with bucket off the ground?

 

[Seans problems]

Yeah, sorry. It smelled like 15w40 was what was in the tranny. I gave it throttle like I was sending into space and still nothing. I chained it to my excavator to see if I could free up the wheels after hammering failed. I got nothing out of this thing.

 

[kshansen]

Okay how about this idea. Can you pick the front wheels off the ground by putting down pressure on the bucket?

If so with front wheels off the ground try rotating the wheels by hand. Unless it has a locking differential on the front end you should be able to, with a good tug on the tire, rotate them. One will turn one way and the other the opposite direction due to the differential. If that much turns at least you know the problem is not the front brakes!

Now if you had something big enough to safely pick the rear wheels off the ground you could try the same at that end.

Trying to diagnose this from the other side of the country is tough!

Some of the ideas I may have need one to be very careful and understand the dangers as they can cause the machine to no longer have working parking brakes so if that is a danger due to were it is presently located I would be hesitant to have someone unfamiliar with the machine try them.


You could try removing the center driveshaft to see if machine will move with that out as that should let the rear wheel at least pull the machine backward if you raise the front wheels off the ground. One problem of trying to remove the center driveshaft is it could be under tension if the parking brake is what is holding it. So be very careful if trying to remove the drive shaft!

I may have one or two more ideas but will wait to see if any of what I already suggested gives some useful information or maybe someone else will chime in with thoughts of their own.

Is there any chance of getting a video from a safe distance that would show the center drive shaft and parking brake area? Preferably with the brake being applied and then released and then with the transmission being shifted from forwards to reverse? Like the saying a picture is worth 1,000 words and a video is probably worth 1,000,000. Something that would take me hours to put into words and you another hour to try to answer could be solved with a 30 second video.

 

[Seans problems]

Sorry, I have been pretty busy working on a couple other things that took priority. I will try to get to the center driveshaft tomorrow. I had someone release the parking brake and try to move it forward and backwards while I looked to see if anything was seized up. I saw the center driveshaft twitch as if it wanted to move in the both directions but then I got called out to a service again.