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56 Cat D4

Runninb

Member
Joined
May 3, 2016
Messages
5
Location
TX Hillcountry
Hey everybody. I'm new here so any help would be appreciated.
I have an opportunity to acquire a 1956 Cat D4 from my uncle. I saw acquire because he told me that if I could get it running I could have it as long as I did a little clearing for him at his ranch. He nor I know of anything wrong with it other than it has been sitting in the same place for about 6 years and that the pony ending was typically a little hard to get running. I guess my question is...is this machine something I should spend some time and possibly a little money to try and get it running. I have about 65 acres of mesquites and small brush that needs to be cleared on my ranch and thought this would be perfect to use since it would not cost me much to obtain it. Next question is, where would I start with this and if I needed parts where would I get them from.
Thanks in advance for any suggestions.
 

Don k

Well-Known Member
Joined
Apr 23, 2015
Messages
197
Location
bandera, tx.
I also live in the Tx. Hill Country. First I would look to see if there is any water or maybe a whole lot in the oil in the pony and main engine. Pull the plugs carefully and let out water until oil flows. Check the pony and main to see if they will turn over. If they will then you are 90% there. Drain the pony gas tank if it has any thing in it. Take the spark plugs out and hook up a battery and turn it over. If it does then add some gas to it and oven all the petcocks. Open the bottom drain on the carb. until fuel flows. Reinstall the spark plugs and choke the pony and see if it will start. If it does then let it run for a few minutes. Stop it. Check for water in the diesel tank. If none and it has diesel then restart the pony. I am not sure about D-4's but because I have a D-7. There should be lever that you pull up on the left side that engages the pony. Make sure the main engine throttle is closed. Pull up on the lever to engage the pony. The main engine should start to turn over. Let it turn for a minute or so then slowly advance the main engine throtle. I know there are many on here much wiser than I but this is a start.
 

Runninb

Member
Joined
May 3, 2016
Messages
5
Location
TX Hillcountry
Thanks for your reply.
I have watched videos on how to start that thing and it seems like you need four hands to get it all done. So I assume it's worth the time to see if this thing will come to life? Also, any suggestions on places to find parts in the event some are needed?
 

d9gdon

Senior Member
Joined
Feb 12, 2010
Messages
1,517
Location
central texas
Your local Cat dealer still has parts for it. Buy a parts book from Ebay or somewhere because the dealers don't want to mess with looking them up on microfiche and will slow walk you to the door.

Parts are available from lots of other places as well.
 

old-iron-habit

Senior Member
Joined
Nov 22, 2012
Messages
4,233
Location
Moose Lake, MN
Occupation
Retired Cons't. Supt./Hospitals
Thanks for your reply.
I have watched videos on how to start that thing and it seems like you need four hands to get it all done. So I assume it's worth the time to see if this thing will come to life? Also, any suggestions on places to find parts in the event some are needed?

If you start it according to the book or the correct video(by Sasquatch) you do not need 4 hands. Most of the starting videos out there on u-Tube make me cringe when I watch them.
 

Don k

Well-Known Member
Joined
Apr 23, 2015
Messages
197
Location
bandera, tx.
Like old iron habit says it is actually very easy. I have a D-7 i7A with a pony engine. I could start it with one hand if needed.
 

sealark37

Well-Known Member
Joined
Jun 3, 2012
Messages
120
Location
Davidson, NC
Occupation
Retired pilot, old equipment mechanic
The first place to look for trouble is the pony engine fuel system. Tank corrosion, plugged fuel lines, carb full of trash, are all possibilities. If you have the time to learn, your old D4, (7U, I presume) will do the job on mesquite and brush. Genuine CAT parts and after-market parts are available. There is also a kit to convert to electric starter. Good Luck, and Regards, Clark
 

old-iron-habit

Senior Member
Joined
Nov 22, 2012
Messages
4,233
Location
Moose Lake, MN
Occupation
Retired Cons't. Supt./Hospitals
And never use the kill button to shut your pony off. Its just for emergencies. Shut your gas off and let it idle until it runs out of gas. It will tell you this in every operators manual that Cat ever put out with a pony started piece of equipment. The reason for this is that the pony only holds a bit over a quart of oil. The juggling of the machine rattles the carburator needle valve and before long the gas is in the pony pan diluting that quart of oil. Not long after you have a failed engine. They are great old machines but they do have a few simple rules that need to be followed and they will run for another 80 years with little trouble.
 

D3DaveC

Well-Known Member
Joined
Sep 12, 2010
Messages
178
Location
Lake country
I'm sure you will need to clean the pony tank and carberator. If mag has no spark usually just need to file the points a bit to clean them. Good tough machine.
 

Runninb

Member
Joined
May 3, 2016
Messages
5
Location
TX Hillcountry
Took a look at it this weekend. Pulled what I figured was the oil plug for the pony and it came out pretty milky. Light was getting a little low and I couldn't seem to locate the plug for the main if there even is one. My uncle gave me his service manuals and parts books for it so that is a plus. Pulled what I was told was called a prefilter and it was basically a vacated wasp nest. My son said he could hear what he thought was wasps in the canister below that. I'm assuming that's the main air filter. Fuel tank on pony looked pretty bad inside. How would I go about cleaning that out. I guess I would need to remove it. Didn't look terribly difficult. Diesel tank had water in it but drain plug in rear loosened with minimal help and finally, fan belts on pony and main need to be replaced. Sorry for being long winded. I just have no one that I know that can help me with this thin and I can't see letting it go to waste. Oh. One more thing. I'm sure I can find it in the manuals but would I use just regular 30 or 40 weight oil for the pony and like rotella for the main.. I do appreciate everyone's help on this. Y'all have been great.
 

old-iron-habit

Senior Member
Joined
Nov 22, 2012
Messages
4,233
Location
Moose Lake, MN
Occupation
Retired Cons't. Supt./Hospitals
Took a look at it this weekend. Pulled what I figured was the oil plug for the pony and it came out pretty milky. Light was getting a little low and I couldn't seem to locate the plug for the main if there even is one. My uncle gave me his service manuals and parts books for it so that is a plus. Pulled what I was told was called a prefilter and it was basically a vacated wasp nest. My son said he could hear what he thought was wasps in the canister below that. I'm assuming that's the main air filter. Fuel tank on pony looked pretty bad inside. How would I go about cleaning that out. I guess I would need to remove it. Didn't look terribly difficult. Diesel tank had water in it but drain plug in rear loosened with minimal help and finally, fan belts on pony and main need to be replaced. Sorry for being long winded. I just have no one that I know that can help me with this thin and I can't see letting it go to waste. Oh. One more thing. I'm sure I can find it in the manuals but would I use just regular 30 or 40 weight oil for the pony and like rotella for the main.. I do appreciate everyone's help on this. Y'all have been great.

Go to the ACMOC sitem and register there. Few thousand of us old Cat farts there. You will get lots of help and may find some club members near you. Good way to clean your pony tank is to put 3/8th nuts in it and sppphake it for a few hours. Some have tied them to a tractor wheel and go do field work. Or tie to a cement mixer and let it spin a few hours. Let your imagination be your guide. After clean use Redcoat or a similar tank coating product if it has pin holes which is not uncommon..
 

Runninb

Member
Joined
May 3, 2016
Messages
5
Location
TX Hillcountry
The property is near a community called Doss. It's about 12 miles east of Harper if you know where that is. Harper is 20 miles east of kerrville.
 

Don k

Well-Known Member
Joined
Apr 23, 2015
Messages
197
Location
bandera, tx.
Yes, I go to Harper often to Razz Exotic Livestock Auction often. Drain all the fluids. See if the pony will turn over. See if the main will turn over. If it is in gear leave it there and release the clutch to see if it stuck to the flywheel. If all is good then put oil in the pony and its gear box. Turn it over and see if you can get a spark on a plug. It is going to be a long process. Do one at a time before spending a lot of time and money that may be wasted. Like the pony gas tank. Make sure the pony might run before cleaning out something you may not need.
 

farmerlund

Senior Member
Joined
Nov 22, 2014
Messages
1,237
Location
North Dakota
Occupation
Farmer/ excavator
If I was starting on your project I would check all fluids and figure out if the clutch is working. if all is good than I would pull start it and get the main running first, than you would know if its worth continuing to work on, plus you can get it to your shop or place to work on it. When you have it running you can check the steering and brakes to see if they need attention. They pull start fairly easy.
 

old-iron-habit

Senior Member
Joined
Nov 22, 2012
Messages
4,233
Location
Moose Lake, MN
Occupation
Retired Cons't. Supt./Hospitals
If I was starting on your project I would check all fluids and figure out if the clutch is working. if all is good than I would pull start it and get the main running first, than you would know if its worth continuing to work on, plus you can get it to your shop or place to work on it. When you have it running you can check the steering and brakes to see if they need attention. They pull start fairly easy.

Pull starting it works great but it is a good idea to pull it with the compression release pulled until you build up oil pressure. They are tough oud birds. Thesday of this week my BIL and I went to an auction which had a Cat 12 setting outside in Northern MN for at least 16 years. He bought it after we discovered we could turn the engine even though they said the main was stuck. On Thursday after insuring the injector pumps and linkage was free, the pony started in short order and beyond belief within three hours of arrival the main was running. An hour later the six flat tires were filled, the blade was lifted and it was drove 3 miles out of the dead end trail to the road to be loaded. But then a grader has no steering clutches.
 
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