changing head gasket on paccar mx13 epa 10... help!!!

if you are can work on a car like that, it should be eaiser for you doing the truck. years ago I was in same boat as you when i bought my truck. Not a paccar but a cat. I just took it all apart which was easier becuase you have much more space in a truck to work. Plus everythinmg is much bigger parts wise which made it much easier. I do all the work. Torque specs are all the same with bolt size and bolt grade. but you have to check everything out and make sure your head isnt warped. I have found that it usually isnt just a head gasket, its usually more to it than that but good luck

 

Tools. You better have a big 3/4" drive torque wrench and a big breaker bar. Then the specialty measuring tools like feeler gauges, dial indicator, sled gauge, quality straight edge etc.

I'm a mechanic by trade. I decided to rebuild an ancient 3406 Cat and I'll tell you, I had to invest close to $1,000 in tools I didn't have (normally the shop supplies all the stuff above and beyond your standard hand tools).

Biggest thing is cleanliness. Wash that engine and the areas above and around it clean enough to eat off, then wash it again. Dirt is very bad. Have a nice, clean bench set up, lay out all your parts on the bench as you go. Mark and label EVERYTHING! Make absolute sure everything goes back into its original place. Don't go mixing lifters, rockers, pushrods etc around. #1 intake goes back to #1 intake etc. Lint-free shop towels work good to wipe out the cylinders of any spilled oil/coolant.

Normally when I do heads/headgaskets, after I'm done I fire it up and let it run 5-10 minutes, then shut it off and dump the oil and replace filter. You will usually get some coolant down into the pan once the head comes off.

 

Unfortunately I don't touch on-road stuff anymore so I can't give you any specifics. More just general advice since I've literally only seen 1 MX engine and I was about 30 feet away.


Take your time. When you rush, you screw up. I would not assume the head is ok and just reuse it. Definitely want to give the bottom surface a good cleaning and check for warpage with a feeler gauge and straight edge (block and head). I don't know if the MX has a liner protrusion spec but if it does I'd make dang sure they're in spec or you'll be opening up that engine again in the near future.

Camera phone/tablet is handy as hell too. Take lots of pictures so you can reference them later if you need to.

 

!st buy a used MX repair book or the down loaded type from any of the on/line sales places then you will have all the info you need to work on your truck?

 

How will you lift the head?
Remember it is a 1 piece head.

As to a manual...........might want to ask these guys nicely if they will help you.
@pushbroom
@spsauerland

 

Here is the technical data, your BPV may be different. Paccar (DAF) is very picky on cleaning cylinder deck. They want no power tools. Just plastic scraper and brass wire brush. The surface is the proper roughness for the MLS head gasket, they don't want it any rougher or smoother. MLS head gasket are less forgiving on surface finish vs a graphite constructed head gasket. The block and head are made of CGI, so not very many machine shops can resurface them. They don't even have a check for flatness on the cylinder head. I seen one where it was checked and found to have an arch to it @ a Cat machine shop. Paccar said this is by design (I don't get it), but they recommended a new head. If the machine marks (striations) appear to be inconsistent, I would recommend a new head. Maybe last gut got crazy with a roloc disc.

 

If this is your first go at a large diesel, Paccar is not exactly mechanic friendly. Cat and cummins seem alot more logical as to what to remove next/ how would I remove this. Paccar is sometimes a multi step process just to remove one item. I think you might want to re-think doing it yourself or at least having someone who has done one before help you.

As to the actual failure, I know you think its just a simple head gasket or poor workmanship but I disagree.
I don't like to throw other shops under the bus until you can have full proof of what happened. Innocent til proven guilty. I have been thrown under the bus before and it sucks. Didn't even get an apology when I proved we had done nothing wrong and it was an unrelated failure. Everyone seems so quick to #### on mechanics these days.

The only time I have ever had a water leak from a Paccar headgasket has been warped block/head or eroded deck surface. As @spsauerland stated, MLS head-gaskets are not very forgiving for damaged block sealing surfaces. If you ran with a blown headgasket for a long period of time I have seen the escaping gasses damage block surface to the point of not being able to sufficiently seal off coolant.