Cat 3126 Rebuild Odyssey

Topic: Cat 3126 Rebuild Odyssey (Read 3992 times) previous topic - next topic

Re: Cat 3126 Fail

Reply #50 – September 12, 2018, 10:45:59 pm

Quote from: gracerace – September 12, 2018, 08:35:41 pm

Ever so close. Maybe one more day. Picked it up with the cherry picker to turn it around. No issue's.

Looks great Chris. Nice job!

see ya
ken

Re: Cat 3126 Fail

Reply #51 – September 13, 2018, 12:07:44 pm

You won't believe this one, it's scary. See those 6 silver bolts. Those are smaller head bolts (40 lbs torque), that were never installed from day one. Had to go buy them. We noticed it while we were assembling the engine.

All the bolts were in groups cleaned. Never left the shop, checked my parts cleaner thoroughly. Neither of us remember them taking it apart.My shop is clean and organized, no way they were miss placed, especially considering the size and length of them.

While they do bolt the head down, they are not around the cylinder area, but they do hold the side of the head down.
May be why the head cracked, will never know! The Brazilian guy ( head say's made in Brazil on it) must have went on his coffee break while assembling the engine.

Bizarre.

Re: Cat 3126 Fail

Reply #52 – September 13, 2018, 12:21:10 pm

Have worked on hundreds of 3306,3304 never saw that before,looks like they don't have washers.

Re: Cat 3126 Fail

Reply #53 – September 13, 2018, 12:58:15 pm

Did you have to special order them? What a screw-up!

Re: Cat 3126 Fail

Reply #54 – September 13, 2018, 01:18:15 pm

Those extra lobes are for non-HEUI engines. They use mechanical unit injectors driven off that extra lobe. The injectors are still ECU controlled but use a cam driven plunger rather than oil pressure to operate.

The extra cylinder head bolts are a cat thing. My thought is they just help keep the gasket held in place on the unsupported side of the head where the pushrods come up. All the big 3500 series engines have that and many don't get reinstalled. Rarely does it even cause an oil leak. I stopped working on cat engines before I went to cat school to actually learn what their purpose is.

Re: Cat 3126 Fail

Reply #55 – September 13, 2018, 01:48:38 pm

Quote from: RvTrvlr – September 13, 2018, 01:18:15 pm

Those extra lobes are for non-HEUI engines. They use mechanical unit injectors driven off that extra lobe. The injectors are still ECU controlled but use a cam driven plunger rather than oil pressure to operate.

The extra cylinder head bolts are a cat thing. My thought is they just help keep the gasket held in place on the unsupported side of the head where the pushrods come up. All the big 3500 series engines have that and many don't get reinstalled. Rarely does it even cause an oil leak. I stopped working on cat engines before I went to cat school to actually learn what their purpose is.

Good info, thanks. No one could answer us. The head came from another engine. We called to see if my other head had bolt imprints or even holes, but they threw it away already.

This head had bolt imprints in it. Cat had the bolts, but would have been a few days. Went to the hardware store, and bought new one's. Only could get 8.8, but they only torque to 40 PSI, wasn't worried about it.

Washer are not shown in Cats engine parts diagram. Only for the big ones. The head imprint confirmed it.

Cheers

Re: Cat 3126 Fail

Reply #56 – September 13, 2018, 01:53:33 pm

Quote from: mike leary – September 13, 2018, 12:58:15 pm

Did you have to special order them? What a screw-up!

Western States Cat has everything, if not it's at one of their local 3 stores. They had one bolt in Hayden in one direction, 5 in Spokane in the opposite direction. All 6 in kalispel Montana.

They are really good on parts, I mean every little o ring and bolt. But everything is sold with no return. I even have an account.

They would have cost me over $40.00 with Washington tax, plus all the driving. I paid $15.00 at Ace 2 miles away

Chris

Re: Cat 3126 Fail

Reply #57 – September 13, 2018, 02:03:35 pm

All the Cats I worked on were the nat. gas models,used most of the diesel parts so for the gas everything was overkill,think the
head bolts were only 165.The nat. gas made working on the engine a lot cleaner.

Re: Cat 3126 Fail

Reply #58 – September 13, 2018, 02:16:15 pm

Quote from: John44 – September 13, 2018, 02:03:35 pm

All the Cats I worked on were the nat. gas models,used most of the diesel parts so for the gas everything was overkill,think the
head bolts were only 165.The nat. gas made working on the engine a lot cleaner.

It's fun now, everything is clean. Can wear my good cloths to work on it. Not so much pulling it out.

Re: Cat 3126 Fail

Reply #59 – September 13, 2018, 08:19:34 pm

Ready to go in. Lots easier working on it on an adjustable bench, then in the coach. But that's not all that bad either. If it was anything but a Foretravel, I wouldn't have attempted it.
1st engine I ever worked on, that I didn't end up with bolts left over. Actually had to go buy an exhaust bolt, sure it will turn up.
Glad I took lots of pictures before I pulled it, a few brackets were confusing.
Lets rock this thing
CW

Re: Cat 3126 Fail

Reply #60 – September 13, 2018, 09:02:24 pm

Quote from: RvTrvlr – September 13, 2018, 01:18:15 pm

Those extra lobes are for non-HEUI engines. They use mechanical unit injectors driven off that extra lobe. The injectors are still ECU controlled but use a cam driven plunger rather than oil pressure to operate.

All Detroit 2 cycles have the "extra lobe" to operate the unit injectors for each cylinder. The earlier mechanical Detroits had a mechanical linkage a.k.a "rack" to operate the injectors while all the Detroits 2 cycles that Foretravel fitted are electronic so a the ECU operates them. In other words, no rack to run that was labor intensive and required experienced mechanics to do it.

The Detroits have two camshafts, one for each bank and being a two cycle, operate at crankshaft speed not half speed like the CAT does.

Little tidbits.

Chris is doing this at record speed. Great photos and posts!

Pierce

Re: Cat 3126 Fail

Reply #61 – September 13, 2018, 09:21:43 pm

Nothing sexy'r than yellow and black. Great job on masking those valve cover decals. I'm guessing fuel bleed time is going to be tough and messy.

Re: Cat 3126 Fail

Reply #62 – September 13, 2018, 09:49:08 pm

Quote from: Old phart phred – September 13, 2018, 09:21:43 pm

Nothing sexy'r than yellow and black. Great job on masking those valve cover decals.
I'm guessing fuel bleed time is going to be tough and messy.

Thanks. If I was a rich guy, would have chromed the gear cover...LOL

It has an excellent hand prime pump, that works great. I also have a manual hand Vac pump I can suck it out of the rail with.
Have several idea's for the oil. It has always been an easy starter, everything is pre-lubed.
The lower end will have oil pressure before it start's, because the HUEI pump has to create much higher pressure before the computer will let it start, do to the actuator control Value
CW

Re: Cat 3126 Fail

Reply #63 – September 13, 2018, 10:01:51 pm

Yep warm oil may allow it to spin faster, my cat spins to life in less than 1 Mississippi one. Amazing for a diesel.

Re: Cat 3126 Fail

Reply #64 – September 14, 2018, 10:15:36 am

Did you install new O rings on the injector connections as Dave Atherton has mentioned? Oil intrusion into those connections can cause a mis-fire. Fix under $3.

Re: Cat 3126 Fail

Reply #65 – September 14, 2018, 11:08:28 am

Quote from: wolfe10 – September 14, 2018, 10:15:36 am

Did you install new O rings on the injector connections as Dave Atherton has mentioned? Oil intrusion into those connections can cause a mis-fire. Fix under $3.

All the injectors had new Cat O rings installed 500 miles ago, when trying to resolve oil usage issue. They still look new.

All the fuel and oil line's received new Cat O rings.

I replaced 4 of the harness plugs that were broken with Cat Part # 3669748:

366-9748: Wiring Kit | Cat® Parts Store

I like the replacement plugs because they have metal clips. But the old ones were fine. They only get broken when you remove them.

The rest of the plug seals were fine, cleaned and sprayed contact cleaner in them.

I have one extra plug on board in my parts bin

Thanks for looking out for us

Chris

Re: Cat 3126 Fail

Reply #66 – September 15, 2018, 07:45:39 pm

Chris,
The engine really looks good. I'm not sure any amount of money would get you the job you have done.

Re: Cat 3126 Fail

Reply #67 – September 15, 2018, 09:54:03 pm

Quote from: Green99 – September 15, 2018, 07:45:39 pm

Chris,
The engine really looks good. I'm not sure any amount of money would get you the job you have done.

Thank you, labor of love.
Chris

Re: Cat 3126 Fail

Reply #68 – September 17, 2018, 08:55:48 pm

It's in. Cherry picker worked great. Saved the hassle of renting a fork lift
Trans bolted up, torque converter bolts in. Just start hooking stuff up. Got busy, racing this weekend. probably Be next week.
Chris

Re: Cat 3126 Fail

Reply #69 – September 17, 2018, 08:59:31 pm

Re: Cat 3126 Fail

Reply #70 – September 19, 2018, 09:50:58 pm

Fired right up. No more smoke....Just need to put the P/S pulley on, and a couple of other things.

https://www.facebook.com/racerforchrist/videos/10212614608706459/

Re: Cat 3126 Fail

Reply #71 – September 19, 2018, 10:29:48 pm

I'm guessing your one proud papa, for bringing this baby back to life. Hope your grin doesn't break your face. Rock on!!! You the MAN

Re: Cat 3126 Fail

Reply #72 – March 18, 2020, 07:24:49 pm

Just for giggles, update:

7K miles so far, 3,400 Yuma winter trip. Zero oil leaks

Looks fresh as a babies butt!

Used 1qt oil.

It appears it doesn't use any oil till it reaches 2K miles, then at 3,500 or so, it uses 1 qt. Both oil changes it has done this.

Averaged (not got, averaged) 8.5 MPG. Sweet spot is 1780 RPM's (62 mph) Ran it 65 mph , could see a 1 mpg drop.

Most the time the silverleaf was showing 10-11 MPG,

Cheers

Re: Cat 3126 Fail

Reply #73 – March 18, 2020, 08:08:04 pm

You are less than a buck a mile now after the rebuild. Slowly driving the money out of the coach

Re: Cat 3126 Fail

Reply #74 – March 18, 2020, 08:22:46 pm

Quote from: Caflashbob – March 18, 2020, 08:08:04 pm

You are less than a buck a mile now after the rebuild. Slowly driving the money out of the coach

It owes me nothing now Bob, it has given me both grief and joy. But the experience gained was worth it. The joy now, is over the moon. There is no other coach I would want.

Thought I didn't like Cats, but there are a lot of things I do like. Like industrial strength block. Put it along side a 8.3, and it's like 4.0 jeep engine sitting next to the Cat! (no offense to you 8.3 guys, it is a good engine too)

The Foretravel coach with a Cummings came with a 100K warranty, with a Cat 200K. That tells you something.

I believe all the grief was, because someone got it hot, and for sure lack of maintenance (not on my part)

Total miles traveled since owned 25K, and it's never left us stranded!

Cheers
Chris

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