Search results

  1. L31MaxExpress

    Marine intake up for grabs. (Free to good home.)

    Which truck is your new marine intake going on? Since you have the manifold laying aroubd loose, if you find time, please throw it on a scale assembled. Curious what it actually weighs ball park. I know the thing is surprisingly heavy though. I feel like it is probably 60+ but I might be over...
  2. L31MaxExpress

    Fairly new AC system barely cools truck

    Another thing I have run across, the accumulator blanket does make a difference. If yours is missing, GM sells a blanket for the new Express vans that fits the older GM accumulators like a glove. The older R12 era G-vans did not even come with one, but it has one now and the suction hose has...
  3. L31MaxExpress

    Fairly new AC system barely cools truck

    Another good point, although I would also check the recirculate one as well. In high heat and humidity that one can result in poor performance as well. Switching between recirculate and outside air should make a very noticeable difference in both vent temps and blower noise. There are ambient...
  4. L31MaxExpress

    Fairly new AC system barely cools truck

    I will also mention the Sanden 4261 in my 97 Express still cooled adequately at highway speeds even with the wrong rear expansion valve that was dumping way too much refrigerant through it. On 105F day it would still pull mid-low 40s at highway speed with both blowers cranked up to high fan...
  5. L31MaxExpress

    Fairly new AC system barely cools truck

    OSC 4721 is what is in my 99 Tahoe, provided they are still being built the dimensions spec'd on RockAuto's site. I went through 3 different condemsers for the 87 G20, all built wrong, before adapting a replacement for a Peterbilt into place. The one I adapted into place on it covers the whole...
  6. L31MaxExpress

    Dart iron eagle or ported 193?

    The Darts do have an advantage when it comes to durability. The 193s are great heads for a truck application and even better properly ported, but those Darts are a much thicker casting and less prone to cracking.
  7. L31MaxExpress

    Fairly new AC system barely cools truck

    One other idea based off what I recently ran across myself. There are issues with many new fan clutches on the market. Make sure when you start the truck the engine fan is actually moving adequate airflow. With the ac and warmer ambient temps the fan should have a fairly strong pull of airflow...
  8. L31MaxExpress

    AC issue replaced everything

    Confirm power and ground to the clutch is the first step. If it does not have power or ground next step is to find out why. The low pressure cycling switch on the accumulator is a high failure rate component on these trucks. If it has power and ground to the clutch, the clutch is defective.
  9. L31MaxExpress

    98 Vortec 5.7 MAF needed

    It can be more accurate in reading the airflow volume, the sensor reponds more quickly and reports the flow more accurately with less drift as the sensor ages. The PCM uses the output the same as before as long as the sensors output is calibrated correctly through the curve. I replaced the MAF...
  10. L31MaxExpress

    98 Vortec 5.7 MAF needed

    The plastic sensor is a more accurate and reliable drop-in replacement.
  11. L31MaxExpress

    High pressure A/C switch on a 92?

    OSC 4544 was what I used in the last 1995 C1500 I worked on.
  12. L31MaxExpress

    High pressure A/C switch on a 92?

    Sounds like you have the wrong condenser. Perhaps a R12 unit. The R12 has SAE threads and the R134a unit has Metric threads. Also dual air SUVs use a wider condenser core than single air trucks. Here in Texas, I use the wider SUV condenser in a microtube parallel flow style on everything by...
  13. L31MaxExpress

    AC issue replaced everything

    GM played Where's Waldo on the orifice tube location in these trucks over the various models and years. Early models were in-line right before the evaporator. Later model trucks were in the condenser. Later model SUVs with rear air were in-line after the lines split for the rear unit. I have...
  14. L31MaxExpress

    Coolant temperatures while towing

    Duramax fan WILL work, but have to change the clutch. I have part numbers for both a spin on and 4 bolt clutch. The 4 bolt clutch does use a 3/4" pilot and needs a 5/8" to 3/4" adapter bushing to work.
  15. L31MaxExpress

    Fairly new AC system barely cools truck

    You need to know what your ambient temperature over the condenser and your relative humidity are. I like using a wet bulb to directly measure it. Without knowing those two values it is impossible to know if your system is falling outside of the designed cooling output. I just checked my Sanden...
  16. L31MaxExpress

    L31 Extreme Budget Build

    Lol yep. Watched the movie with that title not long ago. My plans have slightly changed. Taking the 1997 on the trip rather than this one. Have to pull the 4L85E out of it and reseal the pump this week. Then put some test mileage on it. The nearly daily monsoons have slowed my progress on the...
  17. L31MaxExpress

    12200411 PCM swap for 1996 to 2000 GMT400 trucks

    That it is, 3 upstream sensors and 1 downstream on the 4.3L and 305 with a single cat.
  18. L31MaxExpress

    Fairly new AC system barely cools truck

    Too much oil will cause high pressure as it coats the internal passageways of the condenser and kills the heat exchange. Does the rear unit cool normally? What are the pressures. Need to know the ambient temp, ambient humidity and get the gauge readings at ~2,000 rpm with both blowers on high...
  19. L31MaxExpress

    Redneck DoD

    I have seen a 2500 4x4 suburban on 35s get over 20 mpg. It had a 4BT in it that was turned up a bit.
  20. L31MaxExpress

    Redneck DoD

    I would say it likely has better aerodynamics than my 7,000 lbs brick on wheels. The suburban actually has better aerodynamics than a truck.
  21. L31MaxExpress

    Redneck DoD

    My best friend growing ups parents had a diesel Rabbit. All it did was blow smoke, no acceleration at all. Found it odd because they also had a 70s GMC motorhome with a 455 they drove all over the place. Complete opposite ends of the spectrum. Balance I guess.
  22. L31MaxExpress

    Redneck DoD

    I was actually watching a video today on the Dodge diesel slant 6. Never saw production thanks to cheaper gasoline, smaller 4 cylinder FWD cars and the Oldsmobile diesel tarnishing diesel cars reputations but was getting 25+ mpg city and over 30 mpg on the highway in a fairly large and heavy...
  23. L31MaxExpress

    Redneck DoD

    Bulk rubber a/c hose, crimp beadlock fittings, cushion clamps to support the hoses and an inexpensive hydraulic crimper. Could knock out those lines alot more quickly than trying to fish through aluminum lines that will only corrode again. That is how the conversion vans and older factory rear...
  24. L31MaxExpress

    Marine intake up for grabs. (Free to good home.)

    More like 60+ if it is complete. Just the base was a chore to drop into place on my Express by myself although the most recent time I installed it I was getting over the rona virus and not at 100%. The marine base itself is heavier than a Q-Jet iron intake or Vortec head.
  25. L31MaxExpress

    97 Aftermarket Tachometer

    My OE gauges are dead nuts on.

Latest posts

Members online

Total: 1,195 (members: 36, guests: 1,159)

Forum statistics

Threads
64,990
Messages
1,404,026
Members
52,897
Latest member
Gonzagoe

Share this page

Top