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JoeH

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Everything posted by JoeH

  1. JoeH
    What kinda hobby truck? Hobby dump truck for picking up your own mulch? Hobby rollback to support an existing automotive hobby? 5th wheel for towing some old John Deere tractors? The possibilities are endless. A bit of mechanical know-how is important, and so are some big wrenches! As with all things metal, rust is the biggest enemy to watch out for. Solid bones are important.
  2. JoeH

    B20 Barn Find

    JoeH replied to alex g's topic in Trucks for Sale

    The Go Pedal looks unused...
  3. JoeH
    Unfamiliar with the cat cement. Proper procedure is to clean everything down, wipe it dry, position gasket, place Jake spacer on, position next gasket, make sure gaskets are properly positioned, set valve cover on, take the three bolts to the torque setting in the book.
  4. JoeH
    No, you take them to the torque setting in the book, no more.
  5. JoeH
    We probably have 100k hours on the one truck, 1979 R686ST, with the ENDT676 motor. Still working 5-10 hours a day.
  6. JoeH
    We've been using the rubber ones through our mack dealer for a long time, they work fine. The key is don't use anything on them and do not overtorque the bolts. Do not use silicone, do not use high tack. They lubricate the gasket enough so it can shift and slide. Also, overtorquing the bolts distorts the valve cover, making it leak. We have had to straighten ours out a number of times over the years until we figured out the tricks to seal them up nice.
  7. JoeH
    Reason to keep that lift axle: it's an extra set of brakes.
  8. JoeH
    In PA those trucks are good for 73,280. Tandem axles are only good for about 58k I believe in PA. What you're able to get on the truck depends on the axle weight ratings. Example, steer is probably good for 18k, and the drive tandem is probably good for 44k. Combined you're looking at a legal weight of 62k loaded without that lift axle, depending on what your state regulations are. In PA the lift axle only needs to be down if you're over 58k or the weight rating of any particular axle.
  9. JoeH
    Also, you should be seeing around 25 psi of boost under full load working hard. If you're trolling around empty on flat you'll never see more than 10 or 15. Need to hit a good hill at low rpm in a taller gear to make this engine work enough to build boost if you don't have any weight on.
  10. JoeH
    Thinking about it more, I'm going to go out on a limb and say Fuel Filters are possible. My E7 did that, sounded almost like the Jake brake was coming on above 1500 rpm under load, and didn't quite have as much boost as it should as it neared the governor. Took 2 sets of fuel filters to clear it up, hasn't done it since.
  11. JoeH
    When a cam lobe gets wiped it gets worn to nothing fast. Check for bent pushrod, driver could have over revved the engine and floated the valves a bit.
  12. JoeH
    Before you pull expensive parts, pull the valve covers and see which rocker has too much slop. More often than not, you'll find either one of the engine brake valve plates popped out from a weak valve spring or a bent pushrod, or worn cam lobe. We have had all 3. If it's the engine brake valve plate missing on an exhaust valve then just delete the engine brake.
  13. JoeH
    I'd be surprised if they are the same, but then again the oil pans use the same gasket.... Get VIN numbers from an E6 truck and an E7 truck, ask your dealer for the part number for each timing cover gasket. Same for the front main seal. The E7 can run the steering pump on the front of the timing cover, so I'm sure the covers are different. I'd just sift through a Mack junk yard and find a donor front engine mount. Don't know where you live, but Coopersburg PA has a good one at the Kenworth dealership.
  14. JoeH
    Also make sure those 2 little pins in the side where it says "TOP" are mounted top, they're air bleeders so you don't get a pocket of air against the thermostat when you refill the system. Air won't conduct heat to open the thermostat properly on the first heat cycle. Automotive thermostats frequently don't have those so I drill a pin hole in them to serve the same purpose.
  15. JoeH
    Should be running at 180, that's where all my Macks run, 1979-1995. Dont know what your truck setup is, if it's real light and you have no hills it'll take forever to warm up, it's meant to work hard. A new thermostat would have been a good idea, they're not expensive. Running cold slobbers up the valves, can make them sticky.
  16. JoeH
    Not sure how to add photos at the moment, but we found the oil leaks! There are 10 holes in the oil pan flange presumably for spot welds to hold the reinforcing strip in place. Well, someone never spot welded it, so oil was able to seep past the gasket at the front and rear. $2,000 for a part 90% complete.
  17. JoeH
    I've had fuel filters cause this; replaced them twice a few days apart and it cleared up. Almost sounded like Jake brake kicking on lightly. Fully mechanical '95 E7-350.
  18. JoeH
    I'd never heard of 2 piece pistons until I looked up E7 rebuild kits. What is the advantage of 2 piece pistons vs 1 piece pistons?
  19. JoeH
    Does anyone know if the oil pan threaded bosses in the timing cover and flywheel housing are open to the crankcase or if they're sealed?
  20. JoeH
    It's looking like the oil pan gasket doesn't seal around the 2 bolts front and 2 bolts rear. Pressurizing it made oil pour out of the front around the oil pan reinforcement straps, where it wasn't leaking before. Didn't make it leak at the rear much, but we're going to pull the pan back off, smear some RTV silicone on it all around and see what happens!
  21. JoeH
    Did you set the heads down on a table and smash the injector tips while you had the heads off?
  22. JoeH
    Have you driven a manual trans before? Are you "popping" the clutch or easing it out slowly?
  23. JoeH
    I think we're missing some more details. We don't have acknowledgement that hes releasing the parking brake. When did the truck roll last? Has it been sitting for a long time? What work did you have to do on it?
  24. JoeH
    Sidenote, the part number on my '95 E7 oil pan gasket is the same as my '79 ENDT676. Mack really liked to keep things standard. I'll bet one of the oil pans from my 3 spare engines would have fit just fine, and saved me $2,000. But my daily driver gets what my daily driver needs, no screwing around to save a buck.
  25. JoeH
    '95 rd688s with an E7-350. Horrible oil leak at the rear of the oil pan area, found 2 cracks in the old oil pan so we put a new one on; still leaking. Inside of the flywheel housing is dry. Book indicates there's an "isolated" and "non-isolated" oil pan setup. Do they use the same oil pan? Mine is the non-isolated setup, did the dealership give me the wrong oil pan? Hoping it's not related to the flywheel housing "Silastic" seal to the engine block... Could a flywheel housing-to-block bolt break or loosen and allow enough flex to crack the old oil pan and cause the new one to leak? 21,200+ hours. Any common problems in that area?

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