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How To Install Fuel Pressure Regulator And Fuel Filter. 1964 Cj5. F-134

Discussion in 'Early CJ5 and CJ6 Tech' started by HellaSlow, Jan 3, 2023.

  1. Cj5dale

    Cj5dale Member 2023 Sponsor 2022 Sponsor

  2. HellaSlow

    HellaSlow Member 2024 Sponsor

    Would that still work? I bought that initially cause I was planning on just splicing it into the hard line via a couple hose clamps and a short length of rubber hose. But now I'm second guessing based on the comments about fuel pressure, the engine bay, and fire haha. Should I be looking for something with threaded ends now? Or would The hose clamp splice be fine as long as its back near the fender/steering box?

    Thanks for humoring me here! I'm still really new to all of this so these are all things I have no experience with YET. :)
     
    vtxtasy likes this.
  3. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Being on the suction side rather than the pressure side, theoretically somewhat less hazard. But a suction leak can pull air and interrupt fuel delivery. Best to at least use two clamps on each junction.

    As touched on earlier, ethanol gas can eat hoses - important to get high quality ethanol-rated tubing.
     
    Cj5dale likes this.
  4. timsresort

    timsresort Active Member 2023 Sponsor 2022 Sponsor

    I think you want to push through a filter, not suck. Also, that metal filter is a heat sink, I would use a clear glass or plastic filter hanging on the line before the carb, right where the fan blows air past it.
     
  5. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I suspect you are basing this idea on the general physics, in that a full vacuum cannot ever exceed atmospheric pressure in strength. About 14 psi equivalent, maximum. Why a pump on a water well can never "pull" more than about 25 feet elevation, but a "push" pump can go much higher, without theoretical limit.

    But in this case the pressure side of the fuel pump is regulated to a mere 3psi maximum. IMHO, it could be argued the suction side, at a potential 14psi equivalent, might actually be stronger.

    In real life, fuel filters work fine on the suction side, in my experience.
     
    Last edited: Jan 5, 2023
    timsresort likes this.
  6. scoutpilot

    scoutpilot Member

    A fuel filter does not care from which direction the force is applied. As long as it is installed correctly push/pull doesn't matter.
     
  7. jeepdaddy2000

    jeepdaddy2000 Active Member

    To reiterate post 16.
    Filters will work on either side of the pump.
    The last longer on the pressure side due to the pumps ability to push through the increasing amount of (theoretical) debris versus pulling it through.
    They can save the pump if installed on the tank side due to catching that debris before it enters the pump.
    Pre pump filters are traditionally mounted in the framerail which keeps it from easy visual inspection and can lead to "mysterious" fuel issues to someone that doesn't know it is there.

    I prefer metal filters over plastic or glass. I've seen plastic ones melt both from heat and what seemed from the fuel itself. Honestly, I have a, perhaps, irrational mental block about putting anything glass under the hood on a wheeler.
     
    47v6 likes this.
  8. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    See post #25. :)
     
  9. HellaSlow

    HellaSlow Member 2024 Sponsor

    Thx guys! Based on your advice I'll be mounting it BEFORE the pump. The filter is a cheaper part than the pump and I can swap filters once a year if need be to be safe. I think I'll use the Metal one I have, placed near the fender/frame rail by the steering box (away from heat). I'll use ethanol resistant fuel hose to splice it into the existing metal line. 2 hose clamps on each side. Should I put a flare on the end of the hard line to give a better "grip" for the hose? Or is that overkill/unnecessary?

    You guys have been very helpful so far!
     
  10. jeepdaddy2000

    jeepdaddy2000 Active Member

    My
    My post is more eloquent than yours
    I win:D
     
    PeteL likes this.
  11. scoutpilot

    scoutpilot Member

    A bubble flare at the end of the steel tube will seal better than a straight cut.
     
  12. amboynut

    amboynut Member

    Any filter creates a resistance in the circuit, and a resultant pressure drop across the filter element. A filter operating under "vacuum", i.e. before the pump, is more likely to result in the liquid fuel flashing into vapor (vapor lock) than a filter operating under pressure, i.e. after the pump. That's all plain physics/fluid dynamics and probably only applies here at high temperatures and altitudes. Still, it's good practice to keep all that plumbing and components away from heat sources, especially the exhaust system.
     
    Last edited: Jan 7, 2023
    Fireball likes this.
  13. timsresort

    timsresort Active Member 2023 Sponsor 2022 Sponsor

    Point taken. It was just what I was taught by my dad, never had a problem that way, never questioned it.
     
  14. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    ToucheĀ“.

    Valid point. IF it is an issue, say in hot conditions with a clogged filter.

    The old flathead Ford V8 had the pump on top of the engine and was reputed to have had that "vapor lock" problem. OTH, my '34 never has, in 20-plus years.
     
  15. HellaSlow

    HellaSlow Member 2024 Sponsor

    UPDATE!
    I made my first hard fuel line today and used up most of my roll of Nicopp to do it hahahhaha. I kept the previous routing of the line, up the drivers side and across the front due to ease of routing and the ability to easily access it in the future if need be. I also installed the metal filter in line near the steering box and used ethanol rated fuel line on that side!

    Thanks for all the tips and tricks guys!!!! Here is a photo of what ended up being a 2 day lesson on cutting, bending, and flaring hard line :schooled:. I ended up getting the titan flaring tool, a general deburring tool, and it took me an entire day to figure out the flaring alone. lots of cussing. hahah

    CHEERS!!!!

     
    Fireball, vtxtasy and timsresort like this.
  16. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Looks very nice.
     
  17. Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    X2. Nice job.
     
  18. scoutpilot

    scoutpilot Member

    I hate to spoil the party. The original design has the fuel line running just above the water pump so as to keep it away from the exhaust manifold.
     
    47v6 and PeteL like this.
  19. 47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    Do this and you won't boil your fuel.
     
  20. HellaSlow

    HellaSlow Member 2024 Sponsor

    Ok so...... Just asking for the sake of making my life easier..... and since routing the fuel line in the original path will be a huge PITA...
    1. With the fan blowing the heat away from the fuel line is the line really at danger of boiling? Heres a better angle of how close the line actually comes to the side edge of the manifold:

    2. Could I just add a fuel line heat shield and call it a day? I found this on amazon. I don't care how it looks as I'm not going for a stock resto. :D
    https://www.amazon.com/Shroud-Alumi...l+line+heat+shield&qid=1673194842&sr=8-3&th=1