Register now to get rid of these ads!

Customs copper oil pressure line vs plastic

Discussion in 'The Hokey Ass Message Board' started by ned5049, Aug 1, 2018.

  1. BoilermakerDave
    Joined: Mar 3, 2016
    Posts: 266

    from Las Vegas

    D9CCBD70-6539-43AE-BEDB-5CFD1EB6B38C.jpeg I’ve used copper tubing in several cars with no problems for quite a few years. I put a couple loops in it to soak up the vibration (yeah, I probably over do it), and run it through a grommet in the firewall.

    I had a plastic one once, but I wasn’t comfortable with it. I replaced it before it failed.
    Elcohaulic and coolhandponcho54 like this.
  2. southcross2631
    Joined: Jan 20, 2013
    Posts: 3,761


    Hard to bend over and pinch plastic tubing so you can get home like you can with copper tubing.
  3. Fordors
    Joined: Sep 22, 2016
    Posts: 2,765


    I have had and still do have plastic line on my cars and never had a problem. I wonder if the guys that had a line break off got too heavy handed cinching down the ferrule, if it bites too much into the line whether plastic or copper you run the risk of breakage. Tighten it a bit, run the engine, check and if necessary then a touch more until the leak stops.
    54vicky likes this.
  4. X-cpe
    Joined: Mar 9, 2018
    Posts: 951


    One of the most un-fun jobs I ever had. Oil line broke behind the dash of a new Corvette and the owner ran it until he soaked the back of the dash and the carpets. Then with the car still apart we had to swap buildings with the body shop because they tore down 2/3 of ours due to Metro system construction.
  5. nochop
    Joined: Nov 13, 2005
    Posts: 1,594

    from norcal

    Stuff breaks, happened to me, luckily I was on my way to a job an had some 50/50 solder on board. Nipped a little piece of and put it in the pipe to comp. fitting snugged up the comp. nut and off I went. Always keep about an inch on board just for that. 1/8 inch comp is a little weak
  6. deucemac
    Joined: Aug 31, 2008
    Posts: 1,055


    I had plastic tube and it hardened and broke. So, I used copper tube, coiled and it hardened at the fitting and broke. I went to braided line with Teflon liner, an fittings, a bulkhead fitting for an and adapters at the block and gauge. That was in 1990 on my 1968 El Camino. Now 28 years later, 3 engines since and nearly a half million miles driven, the original lines and fittings are working like the day I installed it. I have done the same on every mechanical oil gauge setup on every engine of every car that I have built for me or my customers and NEVER had any problem. Just remember to engineer some slack for the line going from the engine to the bulkhead fitting and life can be good.
    Deuces and gimpyshotrods like this.
  7. LM14
    Joined: Dec 18, 2009
    Posts: 1,932

    from Iowa

    I just run -3AN or -4AN (doesn't really matter) line from engine to firewall, bulkhead fitting at firewall and -3AN or -4AN from bulkhead to gauge. Simple and never have to mess with it. If you change gauges or pull the engine, the bulkhead at the firewall simplifies things. Did that for many years on race cars.
    seb fontana, deucemac and Deuces like this.
  8. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,548

    dirty old man

    I like to use 3- or4-AN also. Just don't trust either the copper or the plastic.
  9. I use the steel line from the square cab pickups. it has a couple of coils in it. Im not worried about having a guage to tell the oil pressure any how. I learned long ago high oil pressure doesnt necessarly mean long engine life. The idiot light works just fine on my daily driver beater work truck. A 66 GMC. A working temp guage is more importiant to me. It will let me know that the engines getting hot before it overheats. I like the mechanical bourdon tube temp guage.
    Last edited: Aug 4, 2018
  10. egads
    Joined: Aug 23, 2011
    Posts: 691


    Bourdon tube ;)
    Old wolf likes this.
  11. enjenjo
    Joined: Mar 2, 2001
    Posts: 2,499

    from swanton oh

    McMaster Carr has 1/8" stainless steel tubing in 6 ft lengths. I have used it in several cars with no problems yet.
    Deuces likes this.
  12. Thanks guys.... now you have me concerned about the plastic line on mine :D I went out and made sure Dad routed his with no strain, angles or near a heat source and it looks good with no leaks. I've run the plastic line for years on several vehicles with no problems.
    However, I've decided to throw a brass plug into my tool kit in case it ruptures on the road. Easy to get to the port on the block and remove the fitting and put in the plug. Now that I have a plug, I'll never have an issue ;)
    Last edited: Aug 4, 2018
    41 GMC K-18, seb fontana and Deuces like this.
    Joined: Jan 13, 2004
    Posts: 2,758


    I have used a light for years , easy install, Never seems to screw up, Hell I even use a light for the charging system also.
    Montana1 likes this.
  14. Gary Addcox
    Joined: Aug 28, 2009
    Posts: 2,348

    Gary Addcox

    I like the way you think, AND you have great taste in rides ! My roadster is red. LOL
  15. Gary Addcox
    Joined: Aug 28, 2009
    Posts: 2,348

    Gary Addcox

    Hey, I think you and I shared a few classes.
  16. 1971BB427
    Joined: Mar 6, 2010
    Posts: 5,687

    from Oregon

    Reviving this old thread because I just went through a plastic line failure last night. A two week old plastic line! I recently got my '39 Chev coupe on the road and was headed out to get together with some car buddies for dinner. Got about 5 miles from home when suddenly smoke was pouring into the passenger compartment through the cowl vent. Smoke also pouring out the open hood sides on my car. I fortunately was right by an apartment complex, so killed the engine and turned into the lot.
    I got out to see what went wrong, and found oil all over the engine bay, plus all over the front fenders! The oil on my headers was on fire, but fortunately not much oil, as it quickly extinguished itself. I did a quick look around, and found the oil pressure gauge line had pulled out of the fitting at the engine! It simply slipped out of the compression fitting! The plastic line was extremely soft and pliable from engine heat, and it seems that's what made it let go. Engine was running 175-180 degrees, but ambient temp was around 92 degrees.
    Had the car towed home, and used my pressure washer and degreaser to wash down the body and engine bay. Then bought a copper tubing gauge kit, and replaced the plastic line with copper. I have 10 year old plastic lines on two other hotrods, and I ordered copper line kits for them also. They may eventually crack, or leak, but they damn sure wont simply pull out because they got soft and wimpy like plastic can.
  17. kabinenroller
    Joined: Jan 26, 2012
    Posts: 449


    That could have been catastrophic! I am not a fan of the translucent plastic line that is supplied with most gauges either, but I am also not fond of copper. I recently found some hydraulic spec “plastic” tubing that is used for industrial applications, it is black and is rated at 500lbs. I installed it in my project car being careful how it is routed and making sure there will be no chance of abrasion. The black color makes the tubing almost invisible on my engine.
    loudbang likes this.
  18. Fogger
    Joined: Aug 18, 2007
    Posts: 1,473


    On two of my cars I had a local hose shop make up high pressure lines between the engine blocks and the S&W gauges. On my Roadster I used copper with loops. Like anything any material can fail and spray hot oil. IMG_0906.jpg
  19. Atwater Mike
    Joined: May 31, 2002
    Posts: 10,092

    Atwater Mike

    Ah, so familiar! In the '80s when I had my shop, younger brother hung around, his stoner friends would drop by. I'd run 'em off, almost daily!
    One late night, brother comes driving in the door with his '50 Merc.
    "Mike! I broke an oil line! To the gauge..." I knew what to believe...the little accessory gauges (amps/oil pressure) he installed was an oily mess.
    He had 'fixed' it with a pair of my stainless surgical locking needle holders!
    (did I suspect where they went? Oh my, the ends were 'resin-stained', I hadn't seen them in 2 months...) What a genius...easy pinch. Genius: Easily 'purloined'. Plenty more where those came from... (Grrrrrr.....)
    He had started a 'tool collection'. At my unknown expense...
    dirty old man likes this.
  20. The Shift Wizard
    Joined: Jan 10, 2017
    Posts: 1,958

    The Shift Wizard

    I haven't tried it with plastic oil line but I've done it many times with plastic drip irrigation tubing. In fact, it's a standard way that irrigation hose is terminated. Just bend it 180 onto itself and hold it there with a nylon tie, string, tape, or whatever. The irrigation kits supply plastic rings to do the job.
    loudbang likes this.
  21. I had a plastic line fail years ago when I was driving down the road- I’m sure it was likely my fault with a poor installation. The hot oil spraying onto the floor and my leg was reason enough to use electric gauges exclusively in anything I built after that.
    Truckdoctor Andy likes this.
  22. adam401
    Joined: Dec 27, 2007
    Posts: 2,017


    I have a braided line going from my flathead to the oil guage. I was worried about a copper line splitting with all the shakes and rattles of an old jalopy. Its silver and looks like shit on a early type hot rod so I wrapped it in black cloth tape. Much better and I feel confident about it. Copper woulda probably been fine but whatever.
    sidevalve8ba likes this.
  23. bobscogin
    Joined: Feb 8, 2007
    Posts: 1,702


    About 55 years ago, I had an old car with a mechanical oil pressure gauge in the dash and copper tubing. The dash lost its ground and guess what the next best ground path was? Yup, the copper tube between the gauge and the engine. Lots of smoke.

    loudbang likes this.
  24. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,548

    dirty old man

    I've been using AN4 braided line for oil pressure gauges since the 50s, and I don't give a rat's ass who thinks it looks like shit. It works and it's safe and secure.
    sidevalve8ba likes this.
  25. 5window
    Joined: Jan 29, 2005
    Posts: 7,368


    There is a chronic shortage of rat asses on the HAMB. over the years, very few people will give one.
  26. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,548

    dirty old man

    ^^^^^^ Just remember, lot's of folks like a little ass, but very few like a smart ass.
    loudbang and Truck64 like this.
    Joined: Jul 20, 2006
    Posts: 2,424


    Like has been said use copper with a couple of loops to absorb vibrations and you won’t have a problem.
  28. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 920


    I sleeve my copper tubing with clear plastic hose from Lowes, then put a clamp at each endin case it springs a hole.. The clear hose also makes the tubing look nice and keeps it shiny..
  29. Bert Kollar
    Joined: Jan 10, 2007
    Posts: 951

    Bert Kollar

    Has anybody found 1/8 cunefer tubing I looked all over Google no luck I do like the idea of stainless though
  30. sunbeam
    Joined: Oct 22, 2010
    Posts: 4,853


    I have never seen copper fail because it was to close the exhaust.

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.