mackrmodel686st

That's my first thought. Just trying to get second opinions.

I drive a 2001 vision with the vmac iii 427. The truck brakes dont seem to do much work and the trailer I pull seems to be doing the majority of the braking. The pedal seems to be sticky or like it clicks when you step on it. I've adjusted the brakes several times and dont get a lot of extra turns when setting them up. If not for the trailer having abs, it would be locking the trailer brakes and flat spotting the tires. Has anyone else run into this problem and if so, what was your cure to the problem? Thanks.

AdKat, that is the plan. I just didn't know which head was which. I know both solenoids were good 6 months ago when we had the heads off the truck as I checked them myself with a power probe. Had one of the shop guys help me look at it yesterday and it started working when he messed with the wires going to the spacers. Makes me think it's the connector at the spacer on the outside. The plan is to steal a connector from a parts truck and try it again, just didn't know which head the second stage is on. Thanks.

Im sure this topic has been brought up before, but doing a search doesn't bring anything up. So here goes. 2001 vmac iii 427. Engine brake only works on the first stage. Had the second stage working for a day, then cut out again. Does anyone know which head the second stage is on? I'm thinking the problem is in the wiring to the valve cover spacer. Thanks.

We checked that for corrosion, didn't see any oil. I've seen on the older trucks with the vmac iii engines that the coolant level sensor will push coolant, but not oil.

We tried that already, problem still the same.

I posted over a week ago and got no responses, so I'll try again. 2015 mack pinnacle with the mp7 engine. When the key is turned to the run position nothing happens, when turned to the start position the dash turns on like the key is in the run position. When you let off the key everything turns back off. Thought that maybe the key switch was bad so we replaced it but still have the same problem. Has anyone run into this problem and could someone possibly point me in a direction to start looking. Thanks.

Here's a weird one. Have a 2015 mack pinnacle with the mp7 engine. Turning the key to the run position does nothing, when turned to the start position everything turns on like it's in the on position but won't start. When you let off the key everything turns back off. Replaced the key switch thinking that was the problem, does the same thing. Turning the key to the accessory position does nothing. Has anyone run across this problem? Thanks in advance.

Truck just got a new motor, the old block cracked. Was having the same issue with the old motor. Oil is fine. I'll try the a ground. I'm assuming fuse 40 is for the ecu, correct?

I drive a 2001 cx613 with the E7-427 vmac iii. The truck starts right up in the mornings when cold, but when re starting after it's been warmed up will either have a long crank before restating or no restart at all without starting fluid. The transfer pump has been swapped out a couple times and a check valve was added to the fuel suction line from the tank at the filter housing. No change in the issue. Has anyone had this problem and been able to fix it? Thanks in advance.

That truck had rods and mains done years ago and the jake stopped working immediately after. Oil pressure always seemed on the low side as well but was within tolerance. We were replacing heads and gaskets and decided to try and fix the jakes at the same time.

I would suppose a rag is possible, the pan was off to replace the pump.

The plugs in the rocker shafts are threaded in to the shafts. I've seen what you are talking about, but I think mack did an update to the shafts sometime between 1999 and 2001.

The pump is brand new.

New filters and new pump.