cat 3304 questions

[Walkerfarms]

i don know if this is the place to post this. Im going to be doing a major over haul on a 3304. This engine as a lot of hours and is getting antifreeze in the oil. I was wondering what kind of special tools I will need if any. Also if there are any thing i should be looking at or for. I will be sure to post some pics once i get started on it

 

[Nige]

What type of machine is the engine installed in..?

 

[Cmark]

On an ordinary rebuild, the only special tools needed are the installers for the front and rear crank seals. (Others will be of the opinion that you can get by without them by using punches and bits of pipe etc., but the seals are reasonably expensive and easy to bugger up and I prefer the peace of mind.)

As far as what to look out for, can you tell us your level of experience and skill in rebuilding diesel engines? What I'm getting at is that no one wants to type a 1000 word essay on, for example, checking liner protrusion for you to say "oh yeah, I know all about that. I've rebuilt hundreds of cummins engines".

 

[kshansen]

On an ordinary rebuild, the only special tools needed are the installers for the front and rear crank seals. (Others will be of the opinion that you can get by without them by using punches and bits of pipe etc., but the seals are reasonably expensive and easy to bugger up and I prefer the peace of mind.)

As far as what to look out for, can you tell us your level of experience and skill in rebuilding diesel engines? What I'm getting at is that no one wants to type a 1000 word essay on, for example, checking liner protrusion for you to say "oh yeah, I know all about that. I've rebuilt hundreds of cummins engines".

I'll second the thoughts on the seal installers, depending on the dealer and how much you deal with them they may lone or rent them to you. Or if possible you could take the engine to them to have them install the seals. Just thought of something else, timing tool for in injection pump. There are ways around that too, but would help to know more specifics about the machine/engine.

Now you did not say anything about the fuel system or much info other than 3304 so I have nothing to go by on what kind of injectors it might have. But if injection pump is going to be part of the project I would say that would probably be best left to an injection system shop, dealer or other.

Plus not knowing your past experience, as Cmark mentioned, would be good to know if you have basic things like a torque wrench and some micrometers. 3304 is about as basic as a diesel can get.

 

[Walkerfarms]

The engine is out of a 950 wheel loader, the sn is 3304pc I will give some back roud on the engine, last summer it started to lose power, I went out and checked it out found that there was coolest in the old and the head gasket looked to be leeking. We brought it back to the shop and I did the head gasket , sent the head to be looked it was OK, but the head gasket was bad. At that time I took an oil sample it came back with high levelschool of coolest not suprising, after 30 hours of running g I took another sample it was very hi in led and copper and still had coolent in it, and still did not have the powwer that it once had. I told my bosses it was time to rebuild it, its kind a ticking time bom. I do have 15 plus years of exsperance, I have rebuilt many engines just never a 3304, I'm going to send the fuel stuff out to another shop. I'm wondering if they are know to have any issues that I should look at take care of when it is apart. I told my bosses that if we rebuild it I'm not doing a half as job. They want to do it as cheep possible. I wanted to rebuild it the first time around but they said no.

 

[bteigrob]

I think you will need a special tool to remove the combustion chambers on that unit to replace the seals.

 

[Wes J]

You will need torque wrenches. I've never done this particular motor, so I'm not sure how big you have to go. You will need a tool to pop the liners out. If you don't have the correct puller, you can have a machine shop make a plug to fit the end of the liner and use some threaded rod to pull them. Then you will need a depth micrometer of dial indicator sled to check the liner protrusion. You'll need feeler gages to set the valves.

I like to tap the holes for the head bolts with a spiral flute tap. I'm not sure what size that engine uses. An engine barring tool is pretty handy as well.

If you plan on doing cam bearings, that's a set of special tools and not an easy job. If you want to do work on the head, you'll need lots of toys like the combustion chamber puller, valve guide drivers, valve seat grinder or cutters, and possibly a puller for the injector cups if it has them.

 

[Mobiltech]

The 3304 has 2 balance shafts that have to be timed when the oil pump is installed. It seems that this can be tricky for a lot of engine rebuilders because I end up going out to quite a few to remove the pan and retime the balancers due to " vibration after rebuild ". The trick is to not install the timing bolts in the balance shaft holes until after you have the oil pump bolted up. When the oil pump goes in it turns the shafts a bit.
You may also need to cut the block where the liners sit if there is any wear in that area. It can be cut and shimmed in frame.

 

[jaluhn]

I have a Cat service manual for the 950 loader for sale, should tell you what tools you need. Send me an email/pm if interested.

~John

 

[Former Wrench]

Something to think about; if you have the money and time. You said the engine was high hour. It may pay to take the engine to a good machine shop, have it boiled out in acid, then have a plug put through the main and cam galleys to make sure you are still in line. It might save a premature failure or worse, a broken crank.

 

[d9gdon]

Take the oil cooler apart and see what it looks like, likely needs cleaning. I'd blank it off and pressure test it just to be sure.

Check liners for cavitation pinholes if nobody has been maintaining the Supplemental Coolant Additives unless it's been changed over to ELC, it usually already has them in it.

Same deal with your pre-combustion chambers, inspect them as well.

 

[bam1968]

x2 on the balancing shafts

 

[gwhammy]

Buddy rebuilt mine about 6 years ago. He had never been in one but I have a shop I use that helped him on info. Wasn't bad I bought a new crank,rods,pistons,sleeves and head. Worked perfect till this morning when a piston let go and now has a rod with pin hanging out of the block. Just bad luck I think, had a 3306 bust a piston a couple weeks ago and window a block. Everyone says these are great engines but I'm not seeing it.

 

[kshansen]

No real experience with the 3304's but worked on many 3306's mostly in Cat loaders and the abuse the quarry people put them to hardly ever killed one under 10,000 hours.

Any engine if abused hard and long enough will fail, then add in poor maintenance or cheap parts and that's another story. Not saying that is what killed gwhammy's engines just saying I had good luck with the ones I worked with or on.

 

[gwhammy]

3304 had good parts but a piston cracking can happen to any engine, the 3306 I know nothing about. Bought it last year and put maybe 300 hours on it. I guess I'll kill the 963, those engines are getting hard to come by and high price when you do find one.

 

[OzDozer]

There are a lot of Chinese pistons and engine parts available for the 3304 and 3306. You install them at your risk. You get what you pay, they're cheap for a reason.
Buy top quality aftermarket engine components such as IPD and you won't have the problem of ventilated blocks.
Piston cracking most often happens due to overheating, another cause is contaminants in fuel causing hot spots.

3304 isn't difficult to rebuild, I rebuilt mine (in-frame) in my Cat 930 loader after it got dusted. If you want to do a thorough engine rebuild, then you need to do an out-of-frame on it. And ensure the cooling system is completely overhauled, along with proper cleaning of engine oil cooler and all oil passageways.

 

[tctractors]

Coolant in the oil on a 3304/6 is most common caused by the water pump, all the 3304/6's have a very fine mesh screen bolted to the oil pump that blocks easy, the result of running water in the oil can knock out the Main Bearings of the Crank quick enough, easy engine to work on if you have skills, the rods are marked for front, the crank and flywheel are marked, the pistons and block is marked, the timing gears to the Injection pump drive are NOT marked, you need to know your crap on them else they will fail fast, IPD make good stuff it's better than CAT, I think I posted pictures of the engine component marks etc in Shop Talk, the water pump is easy to fix for very low $$$ and very worth trying your hand on.

 

[Labrador-tractor]

Buddy rebuilt mine about 6 years ago. He had never been in one but I have a shop I use that helped him on info. Wasn't bad I bought a new crank,rods,pistons,sleeves and head. Worked perfect till this morning when a piston let go and now has a rod with pin hanging out of the block. Just bad luck I think, had a 3306 bust a piston a couple weeks ago and window a block. Everyone says these are great engines but I'm not seeing it.

I'm in same boat as you, place I worked back in 2010 had a 920, a 930 and a 936. 936 always had a miss in my opinion but it lived its life that way. I did the engine in the 920 after it decided one day clearing snow to send coolant out wherever it could on the head. then not long after I left the 930 died also.

my dad had a 1975 930 that blew a head gasket and then the same winter had a pre cup leak coolant into the oil once again.

my buddy had a 910 that vented the block, we swapped a cummins after that.

another good buddy has a old 922 with a d330 now sending a lot of coolant into a cylinder.

another guy I know has a D4 with a window in the block.

my own 920 is down with 1 hour on a fresh overhaul by the previous owner, drain plug fell out and a con rod bearing spun. crank couldn't take the heat and cracked it 2 places, bearing wasn't even that bad.

and my last job we had a pretty large fleet of trucks and equipment, new and old, cat was the minority engine we had by a long shot, and its what we worked on most. I wouldn't take a C7 or 3126 now if it was free haha.

maybe its just shitty luck but EVERY one of these older cats I've been around have an easy life now but been problematic. and maybe they were great 40 years ago and are just all worn out junk now. I will give my 3304 another chance at life though if I can find another crank, if not I have a 4BT cummins in a sea can waiting to breath new life in the ole 920.

 

[kshansen]

Another thread from the past. As the original post was March 2, 2016 and the last post from this person was March 3 of that year I'm thinking that project might not have come out good!