JoeH

An ENDT"B" engine I think would have Mack's Dynatard camshaft. Not sure how the Dynatard worked.

Yea you can run it without engine brake. Where did you get the cam?? I'm a little perplexed that you bent/destroyed a pushrod and wiped a lobe. Be careful adjusting the valves, they have to be done "by the book"! One cylinder at a time. A colored marker on the damper wheel is a big help to see the timing marks and which cylinder numbers you're at...

Number sounds legit. Try it at your local Mack dealer or pull one at a junkyard.

That's a sharp looking engine. I love the colors, just hate the association to MP engines.

Bump

I'd be shocked if a new cam is available, last time we tried getting one for our 1980 DM686SX they weren't available. 5-6 years ago on that one.

Parts engine would be a good investment for this job. You probably have a broken carbide face on the lifter tappet that wiped the lobe off. Common failure. Sounds weird to me that they can't order a single pushrod. Last cam we did we stole from our parts engine, stole cam and one lifter. No need to replace all of the budget doesn't allow. Lifters need to be held up with magnets taped to wooden dowels in the pushrod holes, to keep them up while the old cam.comes out and new one goes in. I think there's a company "Berry Cams" somewhere in the country that can weld new lobe on your old cam, but I have no experience with them. You'll be dropping the oil pan and looking for bits in there, you'll probably find a partial disc from the carbide face. Front engine mount is the timing cover so you'll need to pull oil pan, block the engine up on the block skirt before you can pull the timing cover. Good time to plastigage the crank bearings just to be sure you aren't due for new ones.

If you install the wrong type of switch in the wrong location then you can get a goofy result, like you're seeing.

I believe there's 2 brake light switches on the truck. One is a positive pressure switch on the treadle valve or near it. This senses when your foot hits the brake your lights come on. The other is an "off with pressure" switch, should be mounted on the parking brake valve. This senses when you set the parking brake your lights come on, when you pressurize your brake release circuit it turns off. But it should go off with key.

Other than that they're great engines. We have a 1979 engine still in daily service. It's had a couple camshafts in its life, but we have the donor engines to keep it going.

Ditto on pics. VIN would tell us a lot as well about which HP rating the engine has. A 285-300 HP usually got paired with a 2 stick 6 speed, whereas the 237 HP usually got paired with a single stick 5 speed. Unfamiliar with cruiseliners, so idk what transmission shifting arrangements they had. The engines aren't entirely bulletproof, I assume this truck will have 2 valves per cylinder, not sure if the 4v per cylinders were out in 1980. Weak point on these engines are the lifter tappets on the camshaft. The lifters use a flat carbide disc that rides on the cam, and these carbide faces can crack, a piece falls off and the sharp remaining edges cut the lobe right off the camshaft. I think there's a company "Berry Cams" somewhere in the country that can weld a new lobe on there, but I know the cam is no longer available through Mack, so you're on your own to repair/find donor cam and tappets.

https://www.paiindustries.com/ Here's one more resource for you, if you make an account on this website you can access tons of parts diagrams and part numbers for your truck. Can't buy parts through their website but you can take part numbers and get them from one of their dealers.

FYI your manifold could be eroded. My 95 was when we bought it, back cylinder. Caught it when the engine hydro locked after a rain storm shortly after we bought it. Pulled the manifold, used cast iron welding rods then ground it back down, haven't had a problem in ~13 years since.

At this stage of the relationship "Hon" may become appropriate!🤣

Also how's your batteries? Maybe you have a couple battery cells failing and you don't have enough juice to turn ecm on or work the starter. Gotta start with the basics, not the expensive crap!

Title is No crank No start

Don't have any experience with MP's, but it's possible to have a "dead spot" on the starter or have a bad relay on the starter itself. On my 12v Cummins I had to take jumper cables from the battery right to the starter motor once to get back home. But my 12v has slot less electronics....

Book indicates it stops it from getting in the Control Valve. Never seen an AC in person though. Don't know much about them.

That's where the book is invaluable, it'll tell you exactly what each component does.

It protects the "Control Valve" from "coking."

Book.says it's an oil condensate filter to keep oil out of the system. Depending on Build Date of the engine it may not have had one from factory. I think the pages I sent indicate May 2004 as the change over time frame.

Couple more screenshots from the Book showing some things.

Pages 84&85 for example...

https://macktrucks.vg-emedia.com/ProductDetail.aspx?ProductId=6148 Here's a link to download (free) the Mack Manual for your engine. Click on "View File" to download. It may have a lot of helpful info for you on this dumb EGR system's plumbing.

A little late to the Party, but the Googleweb is a great friend, sometimes. Punched in "Mack AC400 Engine" on an image search and was met with more than a few choices on pictures of engines minus truck frames in the way...