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Big Dog
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Posts posted by steeler

  1. After an injector cup job, while adjusting valves, the plunger on #5 exhaust valve is sticking out a little more than the others. All others adjusted fine, but#5 has a much thinner shim under it, like someone had this issue last time.

    If I push down on the rocker arm, three is a little spring loaded feel to it, not anymore than the others had. Any reason this plunger is sticking out further?


  2. You should have a constant 12v at one wire of the fan solenoid, the other wire is a ground signal from the ecu to disengage the fan. It could be as simple as a blown fuse (don't quote me but #41 I think?) Or could be a break in either the hot wire or ground. 

    I've seen many that were broken wires, rather than chase the mess around and on top of the transmission, I just rewired, bypassing part of the harness.

    I don't have a schematic with me right now, but can give you pin numbers Monday if you still need them.


  3. 13 hours ago, turckster said:

    Aftertreatment fuel psi should be what.... 90ish psi? What test is it that you can not perform that requires a special tool?


    I was wrong on that test, all it was was checking the fuel pressure to the shutoff valve, which is the same as the engine pressure. That was the last test, so it just told me "no fault found". 

    I hooked up another truck of the same year just to compare pressures. That one had an after treatment fuel pressure of 90 psi when the shutoff valve opens, then dropped to zero with the valve closed. Mine stays at about 45 with the valve closed. I'm going to run regulated shop air to the shutoff valve at 32 psi just to see if anything changes.

  4. Hey guys I've got a 2015 lei that is throwing a p20de00 after treatment fuel pressure sensor circuit range/performance fault.

    I've run through the diagnostics with tech tool with exception of the final test because I don't have the special tool to do it, but everything checks good. 

    The afp runs about the same as engine pressure when the shutoff valve activates, then runs about 45 lbs deactivated. Engine fuel pressure is steady at about 58-60.

    Any ideas?


    Forgot to add that I replaced the doser module. 

  5. Depends what type of fan drive you have. I would say you probably have a Horton that locks the fan when there is no air to it. If I have one that isn't kicking in properly for me the easiest way to test the fan itself is to remove the air line that goes to the fan drive. That will lock it in and you shouldn't be able to spin the fan.

    If it's a fan drive that locks on with air pressure to it, then I take the air line off and shoot air to the fan manually and see if it locks.

    I would suspect the fan drive is probably the culprit.

  6. I'll tell you why they won't do anything other than a reman. For one, they don't like the idea of someone "bringing in their own steak" to have them cook it for you. They get no profit in parts that way, just labor.

    2nd, and I'm speaking from experience here is that there is almost always (for my shop anyway) issues with this or that being different/not working with your application. It can become a huge pain in the rear, especially after they give you a quote and end up 20 hrs over what they told you it would cost.

    Our shop went through it not long ago with an mp7. Tried to install engine only to find out there are a zillion different flywheel housings for the mp. And the one on the original engine was no good.

    We won't do it anymore, only Mack remans. Every time we install a customer supplied used engine we lose our butts.

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  7. Hmm. Strange. I was looking up info on a service bulletin and was one click away from ordering impact. Maybe they changed something Idk. 

    Our shop is a "service partner" for Mack. Our dealer isn't helpful with it. We mentioned getting impact thru them but he keeps saying we don't really need it. Wrong. We need it badly. You would think us spending 30k a month in parts with them that they would be a little more helpful.

  8. Our shop has a tool to cap off one side of the cooler and put pressure on the other, but you can idle the engine up to around 1500 and spray around it with soapy water and detect leaks. Do that at hose connections, intake manifold gaskets, everywhere. And don't forget the air compressor intake hoses and pipe, they are boosted as well.

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