Truck#1
1996 Mack RD/690s
E7 300 Electronic Engine.
Bending Pushrods,
After converting from mechanical injection to electronic injection on a replacement motor, my former supervisor forgot an oil drain plug in the bottom of the econovance housing.
So the extreme buildup of oil caused the pump timing to advance wildly to the point where the truck would not start. In the attemps to start, starting fluid was sprayed and pushrods were bent.
We replaced those pushrods and found the plug, removed it and when setting the valves pushrods bent again.
Found binding springs in the heads and had heads remanufactured, replaced pushrods and yet again when setting valves the pushrods started to bind.
Camshaft appears okay, rockershafts look like they are moving correctly with piston stroke and cam lobes. Whats my next move, taking the front cover off and checking timing gears? Whats the chances of it jumping timing.
Truck#2
1994 Mack RD/690S
E7 300 electronic
On this truck, coolant is pressurizing and blowing out of lower overflow (2 tank upper/lower).
I first replaced air compressor, then water pump & housing, new steel upper reservoir, radiator, then cyl heads, new sleeves & pistons installed because a couple had chipped where the fire rings seal, the coolant stopped pushing out for the first cpl days afterwards.
Because of a radiator hose blowing out it lost coolant, after repairing once again same ol problem more coolant pushing out, replaced air compressor with a higher end one hoping it was defective. It still pushes coolant out, theres no exhaust gas in coolant been checked 3 different times & if you run the truck with the radiator cap off you can see large bubbles constantly coming up and making coolant come out as the air purges which pressurizes the system. Im stumped my coworkers are stumped, I removed the pistons & sleeves, Mack came and installed the new sleeves/pistons. I know he checked the sleeve height, cant help but wonder if the blocks deck isn't right or if the water jacket pitting was too much.
Anyhoo, any input on either of these trucks issues would be appreciated.
Thanks! Solomon