Prostar and maxxforce engine

Thanks for the response. We have had them to the dealership for the recalibration. They are Workstar 7600's. The jakes do come on (we think) but they seem to be pretty ineffective (we pick up speed going down hills with the jake engaged). If you move the 1-2-3 switch on the dash, it makes no difference what position the switch is in, it doesn't change the engine brake power at all. We also had the parameter changed to "no delay" but that didnt make an improvement. What I can't figure out is that the truck is designed to run at 1200-1300 rpm but the dealership has told me that I won't experience the full effect of the jake until I get up to 1900 rpm. I understand that but, in my mind there should still be something at 1200-1300 rpm so I pulled some graphs off Jacobs (and other websites). We should have as much (or more in some cases) braking power as a DD13, MBE 4000, C12, C13, etc. at 1300 rpm but our drivers have been telling us that there is 'nothing there' compared to when they were driving the other types of engines. We even had one driver get behind the wheel of our older maxxforce 13 (before they put the jake in them) and he said that truck had way more power and 'as good' engine braking as the newer style he was driving (which has the jake).

I am very excited to get some feedback from others who have these engines. On paper, they seem like they should be awesome. Some other issues we've had...

They had terrible low end power so the dealership's fix was to put a pro star calibration in a work star truck. It improved the low end power but the fan wouldn't shut off. They figured out that the Prostar has a different fan system than the Work Star. So they switched it back. We also have really bad fuel mileage (less than 4 MPG). We were also told that our max torque is at 1000-1200 rpm so we should be almost lugging them up hills in order to get the most pull and maintain speed. However, when trying that, our guys have to keep downshifting because the rpms/speed just keep dropping when they are going up the hills. They end up crawling by the time they are at the top.

On the plus side, our guys love how quiet they are and the turning capabilities are fantastic. I am just wondering if we are driving these things wrong. The guys we have driving them are long term (30+ years) drivers and have pulled other trucks & combinations for us with no problems. We have all of the literature/videos/etc. on the maxxforce and, on the advice of International, have instructed our guys to essentially never get above 1500 rpms but we still can't seem to get the most from these trucks. I like our dealership and we've had a good relationship with them. However, they don't seem to have many answers when it comes to these trucks. I am just wondering if anyone can point me in the direction of a dealership who knows these engines really well and can give us some tips on how to get the most out of these trucks or more tips on how to drive them. Thanks in advance for any advice.

 

You may not have a jakebrake. My 2011 prostar
With the mf 13 has a butterfly valve style engine brake. It works about
As well as dragging a stick on the ground! It's junk! My maxforce 13 engine is rated at 475 hp and 1700 ft. Pounds of tq. Which is completely false. The power is very dissapointing. Our 2009 prostars with 455 Cummings engines pass me in the hills like I'm standing still! International made a bad desision in converting this MANN engine to work in American trucks and emissions

 

Yes, only the 2011 emission (2010 model engine) will have actual Jake Brakes. The other models since they came out only have an "exhaust brake". No, they are not very effective and you cannot even compare them to other engine. The higher the rpms the better for braking efficiency.

 

We have one engine with the "exhaust brake" and two with the "jake brake".

 

Can a jakebrake be installed on the early engine?

 

no it cant, only the new 2010 M.Y. engines can be retrofitted if they wernt spec'd with an jakebrake

 

How can I find out which engine I have? Vin number?

 

If you have your VIN I can let you know.

 

Does anyone know the name of an international dealership who has a really good knowledge of these engines?

 

Same question International is asking!