View Full Version : 1947 d7 3t caterpillar pre crank check ??????????
06-23-2011, 11:00 PM
just needing to know the to do list before cranking engine after this fix.
does oil need to be primed and any certain way to do?
what about fuel any certain way?
would you adjust valves before or after crank or both?
what about antifreeze is there any priming to it? any certain type?
certain type of oil? some say don't use detergent oil in diesel and why?
just want to be sure I'm doing things right.
I do have the books, just you guys have the tech tips.
06-24-2011, 04:49 AM
You are inquiring about valve adjustment and oil priming, so we need to assume you tore into the engine?
1. Adjust the valves before you crank to verify correct adjustment to prevent damage do to misalignment.
2. Fill coolant using the bleeder valve on top of the pony motor to insure the least amount of air present in system.
3. Fuel system priming is a chapter in itself, do a search for previous threads on it.
4. Now your systems are full crank the engine with the run/start lever in the start position waiting for the oil pressure to buildup, this minmizes load on the crank/rod bearing because if the valves are properly adjusted, one set should now be held open.
In answer to the oil type, do a search on that subject also but Delo or Rotella are 2 of my favorite diesel grades of oil. As to detergent it will wash any crud out of the engine and may possibly plug the oil pump pickup screen or oil filter. But your questions are written in a way that we assume you worked on it so I say don't worry about it.
Also, we're assuming that any bearings you went into were reassembled with a good assembly lube or light grease, or at least lots of oil. That will protect them until the oil pressure comes up. I suggest cranking slowly--pony at idle speed--until oil pres starts to rise, or if you have one with the two-speed starter drive, drop it down to low speed for a bit.
My 3T doesn't have a bleeder on top of the pony. Don't spend too much time looking for it. The back mounted starters have them and in that case you'd better use them.
06-26-2011, 05:31 AM
Joke is on me, I was tired when I replied saying there is a bleeder on the pony. I thought it was asking about a D4-3T!!!! I just looked at the Forum this morning and noticed the startup on the D4 was gone but there was one on a D7???? :lol:
06-26-2011, 07:53 AM
The rule of thumb I've always been told regarding detergent oils in old diesel engines applies just as drujinin said, if you have an old engine that's never had it there may be sludge buildup on everything inside it - so when a healthy dose of detergent oil is introduced it begins breaking down the sludge and may cause too much of it to release too fast, clogging pickup screens, filters, or passages that results in damage. Never seen it myself or ever even heard of it happening to anyone else, but people say it can happen.
Now if you had the engine far enough apart to really clean the crankcase, oil pan, and most all of the internal parts inside the engine, the previously mentioned sludge should already be gone so a detergent oil shouldn't cause you problems.
06-27-2011, 02:17 AM
The chances of any Caterpillar diesel engine ever having been run on a non-detergent oil are very low. Even the earliest 3T and 7M D7's called for the use of "Superior Lubricants" Series 2 oil. The instruction book says If Superior Lubricants are not available oils meeting the requirements of MIL-L-2104A can be used successfuly when fuel sulphur content is less than 0.4% with a more frequent oil change period.
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