Caterpillar Part No.7F5225 Break-in Powder

Since there have been discussions of this, I went and looked it up in the stacks of manuals in my collection for old caterpillar tractors and its as follows:


Besides honing or etching the cylinder liners, a third method has been used to hasten the seating of new rings to worn liners. This method uses 7F5225 Break-in Powder. The procedure is as follows:

After assembling and starting the engine, loosen the air cleaner to allow a gap between the flange and the inlet manifold. Rune the engine at about 800 RPM and allow the powder to be sucked slowly through the gap and into the engine. Use 1 1/4 teaspoonfuls of powder per cylinder and then tighten the air cleaner. Run the engine at 800 RPM for thirty minutes, and it is then ready for service.


This method of break-in has been used successfully when facilities were not available for honing or etching liners. It has also been successful when, for some unknown reason, new rings and liners have failed to break-in in a reasonable length of time. If the first powder treatment is not effective, a second one may be. However, if the second treatment is not effective, a thorough investigation should be made to determine the cause of oil consumption.


This was taken from the Caterpillar Serviceman's Reference Book for Diesel Engines (5 3/4" BORE 4-CYLINDER) D8800 Industrial, D8800 Electric Set, D8800 Marine, and D7 Tractor.

Form FE031238-01

The book is a product of Midland Press, whom was printing for CAT at the time, I would need an original book to determine the publish dates, however I believe this applied to the era of their naturally aspirated engines like the D8800 which was in production from the 30's to the mid 50's, with about 50,000 units produced for tractors alone.

This should dispel any rumors or mis information about the use of Break-in powder by Caterpillar.

"new rings to worn liners."

That's the part that is just plain silly. :>)

Allan

Calm down Allan. IHC did the same thing with used liners & rings :lol: :lol: :lol:

It sure is, stood out like a sore thumb when I read it. There was a lot of trials and tribulations with oil and such in those days, this was part of it and I have seen some errors in these old books, funny you picked up on that too, I cannot even visualize it working, worn liner and new rings, always thought you can't have one without the other.

This book contains more specific details about the engine, then the 3 original books that came with a D7 tractor. I did not look in any of those manuals to see if this section was also in the engine section of those, might just appear in this particular book, maybe common knowledge in those days to the engine shops/mechanics at Caterpillar dealers, have to wonder how people reacted to this practice when it was first used.

We bought a new 766 in 1974. Supposedly the rings never seated on it. It was using a gallon of oil per day. We were not happy campers.

The dealer took it in and rebuilt it. Only had a couple of hundred hours on it.

It was OK after than, but still not what you like happening to a brand new tractor. And in those days we didn't get much brand new.

Gene

That was back before we became a "throwaway society".
Loren, the Acg.

Why is that silly? The work involved to remove and rebuild the engine in a large piece of earthmoving equipment is far greater than the labor to do the same in the average farm tractor. Too, back then if a part wasn't worn out the idea was to reuse what parts you could and only replace the parts that were worn beyond factory specs. CAT, for one, has always had a guide showing what was acceptable and what wasn't, along with the standard 'out of service' limits on their pieces. That said if you tore an engine down, say in an old D9, and the liners weren't worn beyond specs, why replace them? In a case like that what you do is hone the liners to get them ready for a new set of rings, clean the pistons (if they aren't damaged), install new rings, and put it all back together.

Regardless of the engine size, what it sll comes down to is exactly what I said before, why replace parts that aren't worn out. Unfortunately, nowdays alot of the thought on reuse vs replace has to do with the cost of labor. In other words the new part is cheaper than the cost of the labor involved to clean and reuse the old ones. In a case like that, then yes, new parts will always be used. Thing is when it comes to the large engines that isn't always the case and the reuse of 6 $500 liners, that only take $120 each in time and labor to reinstall with new seal rings and hone, actually makes good sense.

In the end I'm all for using new parts in a rebuild when necessary, but when the old parts aren't damaged and are well within spec, why waste a customers money when youm don't need to? In fact I'm currently having to do this on a 6 BT Cummins because a customer decided not to go with a reman engine, against my recommendation, and instead went for a repair. They had gotten someone else involved in the 'repair' and I got called in a month later to complete the deal. Now I've got to 'repair' the repair, which has already cost them close to $4000 and do it within their budget. One cylinder has already been bored and sleeved to standard and has a new piston, but to get them back and running now means pulling the other 5 pistons (that had been allowed to set with water on top of them for several days), replacing one of the pistons that has pieces of debris imbedded in the crown, honing the cylinder walls, and reringing the remaining 4 pistons and reinstalling them. While this line of "repair" grates against every bone in my body, but it is the only way to get this engine running again short of throwing the money already spent away and starting over. True it's still got old bearings, seals, etc, but what will be done is as close to doing an 'inframe' rebuild as I can get them, and at this time, unfortunately, it's about their only choice. However with the 'used' cylinder walls properly honed, the old, undamaged pistons, and a new set of rings it's really no different than the conditions you'd find in new/reman engine.

Forgot to mention it in my other post, but a liner is not really any different than the bore in a cylinder block. Think about it like this. If you tore your engine down and it didn't need to be bored oversized, would you bore it just to say you had a 'new' bore, or simply hone it get the necessary roughness needed for a new set of rings to seat? This is no different than reusing an old liner, just as the book suggests doing.

I'm with you, Allan! If you are going to open a "can of worms", do the whole job while you"ve got it open. Why go half way, and then have to open it again? Or, as my mechanic grandfather used to say, "Why is it that people who don't have the time or money to do it right the first time, always seem to be able to find the time and money to do it right the second time"?

In the early spring 1976 I was in training as a Heavy Duty Mechanic. The Caterpillar service manual that was applicable to the Caterpillar engine we were using as the class 'guinea pig', gave a part number for break in powder, and immediately following that number was the words (Bon Ami) in brackets. Thats right, plain old ordinary household Bon Ami.

I can't remember what engine it was other than it was a Caterpillar stationary engine and the service manual was Cat as well, not some after market I&T type.

We didn't employ the process on the engine. The instructor just though we'd get a kick out to of the fact that Caterpillar sold Bon Ami under a specific part number.

People around here that used to have problems with ring glazing on new overhauls (usually from putzing around and not working an engine hard) used to puff Bon Ami powder into the intake. Just a little bit would cut through the glaze and cure the burning oil/slobbering problem.

Silly ain't the word for it.

Cylinders wear in the shape of a bell or an oval when viewed as a profile. Rings new or old cannot expand fast enough in the worn areas to seal and prevent oil consumption. When they expand outward to seal the worn part of the cylinder walls this creates a bigger gap between the ring and piston allowing more oil to sneak by from that side.

Posted this before I saw the Bon Ami post furhter down the page!

I would agree with what you stated about rebuilding and not having to replace a liner if it checks out to be within tolerance, but the word, "worn", to me would mean out of tolerance, or at least a noticeable degree of wear, "worn out" would be an obvious typo, so maybe its just the language/choice of word, what they really meant was along what you said, however a worn liner and new rings, even with a honing, if the liner is beyond or very close to the specification for acceptable tolerance, I don't believe it would perform, could be problematic, ( you would know more than I about it) but say they meant what you said, lack of means to hone or etch the liner, new rings, liner is within tolerance, but has appreciable wear, and is difficult to get oil control, only then did this method become viable or was one employed for the stubborn to seat rings overhauls.

Its kind of interesting to consider how they arrived at doing this.

It is just Bon Ami powder; works well but studies show it reduces ring/cylinder bore life about 33%. So it works but there is a cost.

Billy, Hodeon! If you have a problem take the tractor out and hitch it on to a ton or two of something and haul it around untill the oil stops blowing out the stack. Then you have the tractor ready to go to work and stay to work.
Later Bob

Whoa, LOL!, I don't have any plans for doing some housekeeping ie; engine dusting with a little bon-ami, thats kind of like nails on the chalkboard to me, but thought I'd quote the book, relative to the recent discussion and your are right, no harm in lining up to a big ole stump or pile of dirt, use it for what its meant to do, heated up, should clear out, if not, has to be another way, take it back apart, you would know more than I on that. I've never had either of my old cats wet stack, tried not to idle them long for the most part, but sometimes a little, does not seem to take much to clear em out either, those old 4 cylinder slow rpm motors seemed to run fairly clean when in good shape, under a load, seems when they idle too long its just not good.

Billy NY,

Question: "What does it mean: Run the engine at 800 RPM for thirty minutes and it is now ready for service"?

Does it mean, ready for service as in change the oil and filter. Or, does it mean, put the engine in service, no oil or filter change required?

Thanks in advance.

Funny no mention of an oil change after, likely meant to put it in service as in oil control should be achieved by doing this.

Possible service meant maintenance, but I believe it was an old practice that came about for whatever reason, in the era of those non turbo engines, at some point it was discontinued.

These were slow turning engines, 800 was getting close to max rpms.