As if I don't have enough projects and maintenance to deal with, we just picked up a well-used 1956 Cat D4 7U that I've nick named Old Smokey for obvious reasons. I got it cheap enough considering delivery up to my mining property. It runs "well enough" despite lots of smoke and blowby of oil in the exhaust but I drove it down the 1 mile dirt road to our operation. It has a number of problems that I'll deal with in order of importance and am even considering doing a rebuild of the motor eventually as long as everything else remains reasonably serviceable. The water pump has a slow drip coming from the water pump shaft and appears to be a bad shaft seal. Is there a source for a rebuild kit or am I looking at having to replace the pump? A source for either solution would be most appreciated! Thanks, -Tom
Work it hard and the smoke may clear up. They start slobbering oil when they're just idling around.
Yes, I noticed that I was at high RPMs and travelling down our road the smoke wasn't visible, and when I throttled down at the end the smoke came back. After shutting it down the visible oil from the exhaust stack flange is what suggests lots of wear and blowby. But as long as it still moves with some authority it will serve it's purpose for us. It lost the pony motor and has a hefty 24-volt starter with new brushes on the bell housing, undercarriage is fair, pads and grousers look very good, clutches and brakes seem fine, it travels straight, and is a kidney bruiser due to no cushion on what's left of the seat! It's an old farm tractor that has had some hard use with a grafted adjustable angle blade that had required trimming the pads a little with a gas axe in order to clear the blade anchor towers. Looks nasty but for the $$ it's worth the investment. I just need to keep my welder and ample stock of rod handy " just in case" ! Thanks for the encouragement. This is my first Cat, though I once had an old International TD-9 that I kind of wish I still had. But this machine is a little heavier and has the wide tracks.
It is hard to put a good constant load on a tractor dozing. If you could hitch it to a disc and pull it hard for a few hours it might clear up just fine. If it runs nice and even and oil consumption is not too bad I would not think of tearing into it.
Advice from members of this forum is always helpful, and thank you for yours! I'm operating a placer gravel mine and am moving overburden and gravels that cap slate bedrock, so running a few hours at a semi-constant rate is a bit problematic, though I can try by doing some brush and dirt road clearing and leveling at first. It's going to be a new learning curve for me, just as it was when we got our abandoned excavator finally up and running after almost a year of "learning"! Thanks again. -Tom
All of the water pump rebuild parts are still available. The impeller shaft can get pitting after 65 years, especially when a cooling system has not been maintained. As far as the smoke goes, you can set the individual injector pump height to make up for wear and it will run better too. You need a service manual or somebody might come along and post the procedure on how to do it. It doesn't take long to do if you have another person helping. All kinds of help at www.ACMOC.org...that's the antique Caterpillar website. Reset the valve clearances while you're at it.
Much appreciated d9gdon! I'm balking at the near-$300 price of the full manual kit from Jennsales at the moment, but it DOES include a Cat shop rag as a bonus! I got manuals from them in the past when I was working on the shuttle for my Ford 555 and have no complaints at all. But a shop manual and parts manual certainly are a necessity for Old Smoky. I'll take your advice and link up with ACMOC. Many thanks, -Tom
$300 is a cheap investment in the long run. A service manual and correct parts book can save a lot of time and aggravation if you have minimal experience with a machine
They're only $30 on Ebay... https://www.ebay.com/itm/272938291766?hash=item3f8c63d236:g:TZIAAOSweM1aDfQP
Thanks for the link but the "Serviceman's Service Manual" listed appears to be just an overview and not comprehensive enough to be useful to us. Guess Im I'm leaning toward biting the bullet and going with JennSales manual kit. The manuals I got from them in the past for our Ford backhoe were excellent and clean reproductions. -Tom
I ordered a service manual, operators manual, and parts manual off eBay for my 1950 d4 7u off eBay last week... got all 3 for around $100 total. Service manual is 166 pages and covers everything besides engine overhaul. Parts manual is 320 pages and has way more info than you'll ever need. Thinking about taking it apart and removing all the pages that don't apply to my serial number actually. Operator manual has basic maintenance stuff like valve adjustment and the like. Just so you have an idea of what's on eBay. I assume you would need to order a manual for that specific Cat engine, not the tractor, to get more detailed engine overhaul and adjustment stuff.
Thanks for the lead, Matt. I see that the Parts book you have is for the earlier serial number machines while ours is 7U38240. So I'll check on eBay though know that JenSales has the correct ones. Many thanks! -Tom
Hi Tom. I've been wondering how you're doing the past year and a half. As stated, eBay will be your best bet for manuals. Just look for the CAT manual that covers your serial number. As for your oil issue, add some Marvel Mystery Oil to the fuel and engine oil before you tear into her. MMO frees stuck rings. Loosens up the carbon enabling them to function properly. Spitting oil is a pretty common occurrence for those old girls. I thought I broke a ring on our first 7U. An old mechanic friend of ours told us to use MMO and that fixed the problem. We still add maintenance doses when they're sitting for a while.
Hi CB. I've been doing great and eventually mastering issues with the various mechanical beasts including the Ford backhoe and the big excavator for my mining operation. My search on eBay for manuals wasn't especially promising, so for the sake of a quick and confident solution my equipment partner and I have decided to go with the deluxe manual set from JenSales in PDF format and download so that each of us will have a full copy of the manuals for our machine. The manuals I got from them when rebuilding the shuttle on my Ford backhoe were perfect, and I couldn't have gotten the job done without them AND assistance and tips from members of this forum during the process. Thanks for your input too! -Tom
You might check with Peacefull Creek manuals ,if it's available from then they have very good manuals and prices.
Thank you for the lead but I went ahead and downloaded the PDF versions of JenSales' deluxe manual kit because I need to get into this while I'm still motivated and don't want to wait for delivery by mail, plus my equipment partner can have a copy too. It works out to an initial cost of $201 for the Operator, Service, Parts, and correct Engine manuals with an additional equipment serial number manual as a bonus. I don't think $50 for each is too bad a deal, especially since I can copy the files to my laptop for when I'm in the field and for multiple backups. Regards, -Tom