Replacing rear heater hard coolant lines

Discussion in '80-Series Tech' started by kbellve, Nov 8, 2005.

  1. kbellve

    kbellve

    Messages:
    152
    Likes Received:
    0
    Joined:
    May 30, 2005
    Location:
    Hubbardston, MA
    The front hard coolant lines to the rear heater failed on my 1996 LX450 leaving coolant all over the ground. I replaced the rear section of the hard coolant lines, which was easy enough, but I see no way to replace the front lines that go between the frame rail and the bodypan and then over the transmission and then behind the head.

    Either I have to pull the engine forward 4-5 inches, or lift the body off the frame. I can't find a method in the FSM to change this line. I have the replacement line, and I don't just want to patch the current line since it will fail somewhere else.

    You would think they would do a better job of corrosion protection on these lines. My 1985 4Runner also had these lines rust through.

    Any ideas how to replace the lines?

    BTW, this engine blew its HG at 90,000. Lexus would do nothing to help fix it. The truck has 130,000 miles now on the replacement HG. The replacement HG may have failed again due to the rapid loss of coolant.
     
  2. powderpig

    powderpig SILVER Star

    Messages:
    1,024
    Likes Received:
    18
    Joined:
    Jul 12, 2005
    Location:
    Boulder Foothills, CO
    I have often wondered how to remove these line if needed. You are the unlucky one to blaze the trail on this one. I can not remember any one haveing to replace these lines. What part of the country do you live in? I know it may be coming into winter, but have you thought about just bypassing the loop for now while you figure out how to remove these lines? this way you cold drive the truck until you have finished the project. I will look at my cruiser today to see what I can see. It is a 93, maybe it will be close enough. good luck robbie
     
  3. kbellve

    kbellve

    Messages:
    152
    Likes Received:
    0
    Joined:
    May 30, 2005
    Location:
    Hubbardston, MA
    yea..I have it bypassed at the moment...It doesn't look pretty. I have removed the 3 bolts holding the line in...but that is as far as I have gotten....my next step is to see how hard it is to move the engine 3-4 inches forward...

    I live in Massachusetts.
     
  4. powderpig

    powderpig SILVER Star

    Messages:
    1,024
    Likes Received:
    18
    Joined:
    Jul 12, 2005
    Location:
    Boulder Foothills, CO
    Figures, east coast snow belt, lots of salt. If you are going to move the engine forward, I would pull the fan, remove the radiator(for protection of the radiator). Un do the fuel line at the filter, loosen all the wire harness, remove the air hose from the air box(may be remove the box for protection and space), remove some of the ground wire to the intake manifold, ground wire at the back of the head, remove the wire between the distributor to coil. I would also just unhook the computer inside the dash and pull the main wires out. You may also have to un hook the wires that go to the O2 senser. Remove the drive lines to the diffs, remove the transmission mount and support the tranny with a jack. Undo the Motor mounts at the frame, I would also remove the hood(give more room for the cherry picker or fork lift). Un hook the exhaust at the manifolds. You may then be able to pull up and forward at the same time to get acess to the pipes. good luck robbie ty
     
  5. stayalert

    stayalert

    Messages:
    1,795
    Likes Received:
    284
    Joined:
    Sep 28, 2004
    Location:
    Norwich, VT
    I have a set of those lines hanging on the wall of my garage. They've been there for about 4 years. When Mine started to leak I bought the pipes and then when they arrived I looked at fitting them. My conclusion at the time was "square peg round hole" unless I was willing to do alot of work (moving engine etc.)

    I cut the hard lines in the area of the leak and added another section of rubber line. Works fine for me......I recall the frustration I had when I noticed my coolant leak. It wasn't enough to drip on the ground....took me awhile to finally find the source of the leak....Good luck....
     
  6. tusk74

    tusk74

    Messages:
    138
    Likes Received:
    0
    Joined:
    Oct 26, 2004
    Location:
    Michigan
    Just cut the metal lines somewhere in the transmission tunnel and route heater hose all the way back to the rear heater core. You can leave the old metal lines right where they are. You would have to remove the cat. heat shield to get them out anyway. The new rubber lines tusk in nicely on top of the frame. If you are worried about chaffing, run the rubber hose through a length of pvc pipe. Most aftermarket, and OEM, rear heaters run rubber all the way back. I double clamped everywhere when I did this. You can carry a piece of the old pipe in your glove box if you are worried about springing a leak.....just splice in the piece of pipe until you can go out and buy $3.00 worth of heater hose to redo the job. I bet this fix will last many years. It is so cheap and easy you could replace the rubber everytime you flush the coolant.
    Good luck
     
  7. IdahoDoug

    IdahoDoug

    Messages:
    8,864
    Likes Received:
    269
    Joined:
    Aug 9, 2003
    I just went out to the garage where my headless 80 is sitting at the moment and it looks like those lines could be replaced with the head off. They can be slid forward quite a ways easily once disconnected since they come into the engine bay right at the level of the top of the block, and you can rotate them at the same time since there's nothing in the way.

    I'm not suggesting pulling the head as a happy solution, but frankly sliding the engine forward sounds like 50% of the work of pulling the head and you get no additional benefits. Plus, you may still not be able to get those pipes off. With the head, you get a coolant flush, new gaskets, a clean throttle body, great time to change the fuel filter, alternator brushes, new hoses at the firewall and heater valve, etc, etc.

    If this appeals, I'll take a closer look and do some measurements on Sunday.

    DougM
     
  8. cruiserman

    cruiserman

    Messages:
    1,861
    Likes Received:
    0
    Joined:
    Mar 27, 2003
    I looked at those lines when the motor was out but didn't replace them. I would do as advised above and just bypass them with heater hose.
     
  9. stayalert

    stayalert

    Messages:
    1,795
    Likes Received:
    284
    Joined:
    Sep 28, 2004
    Location:
    Norwich, VT
    Doug take advantaqge and if you're hard lines are suspect seems like now would be a good times to replace them.
     
  10. IdahoDoug

    IdahoDoug

    Messages:
    8,864
    Likes Received:
    269
    Joined:
    Aug 9, 2003
    Mine look fine - no worries.

    DougM
     
  11. kbellve

    kbellve

    Messages:
    152
    Likes Received:
    0
    Joined:
    May 30, 2005
    Location:
    Hubbardston, MA
    mine looked fine too along the firewall.

    They fail where the lines go over the frame. Check where the lines are bolted, and see if there is corrosion near those spots.
     
  12. concretejungle

    concretejungle

    Messages:
    9,568
    Likes Received:
    771
    Joined:
    Oct 27, 2003
    Location:
    North Cadillac

    that surprises me, you seem to have replaced just about everything else. might as well get these also.
     
  13. outdoort

    outdoort

    Messages:
    149
    Likes Received:
    15
    Joined:
    Apr 13, 2012
    Location:
    Greensburg PA.
    Sorry guys, I'm reviving this thread. I'm planning on removing those rear hard heater lines tomorrow. I wasn't able to finish the job tonight as I wasn't sure how to go about removing these lines.
    I'm not interested in replacing the hard lines with new ones, I just want to remove the hard lines. So I can cut these hard lines anywhere I want and rip them out., but it even looks kinda tough doing that.
    So anyone have a specific way they have done this? I want them removed because I dont want them in the way when I have future projects where I might need the space to wrench back there. Thanks guys, Tyler.
     
  14. outdoort

    outdoort

    Messages:
    149
    Likes Received:
    15
    Joined:
    Apr 13, 2012
    Location:
    Greensburg PA.
    Oh also I'm thinking that I will cut the pipes as far up under near the transmission as possible and ripping the hard lines up through the hood behind the valve cover. But another part of me says that pulling them down from under the car would work better.
    I'm also planning on keeping my rear heater operational when I eventually add back some rubber or silicon lines along side the frame rails.
     
  15. scrowley

    scrowley

    Messages:
    3,537
    Likes Received:
    853
    Joined:
    Dec 13, 2008
    Location:
    N. West CT.
    I just cut mine by lower firewall and ran silicone hose up inside frame rail connecting to the rear heater. I left the old pieces in the truck. No harm in just abandoning them. Has worked great for me for couple yrs.
     
    Last edited: Mar 16, 2014
  16. outdoort

    outdoort

    Messages:
    149
    Likes Received:
    15
    Joined:
    Apr 13, 2012
    Location:
    Greensburg PA.
    Ya I was thinking a lot of people were doing that, but my ocd makes me want the old lines gone.
    No ones completely removed them?
     
  17. ThomHart

    ThomHart

    Messages:
    76
    Likes Received:
    8
    Joined:
    Sep 30, 2008
    Location:
    Central NJ
    I split the dual hard line and was able to thread them both in while doing a HG job.
     
  18. scrowley

    scrowley

    Messages:
    3,537
    Likes Received:
    853
    Joined:
    Dec 13, 2008
    Location:
    N. West CT.
    I am a weee bit OCD too but sometimes you just have to tell yourself not to stress about it. The lines do no harm still in there. Just looks like you still have bad lines but who cares really.
     
  19. outdoort

    outdoort

    Messages:
    149
    Likes Received:
    15
    Joined:
    Apr 13, 2012
    Location:
    Greensburg PA.
    Hey, so just wanted to let you guys know I did leave the rear heater hard lines in place. I think that it will be much easier to remove them if I ever get around to doing a head gasket pm or something more involved than just a simple coolant flush and rear heater bypass.
     
  20. jfz80

    jfz80 bound to cover just a little more ground SILVER Star

    Messages:
    10,915
    Media:
    3
    Albums:
    1
    Likes Received:
    12,508
    Joined:
    Jun 5, 2005
    Location:
    Madison NC
    If you wan to read up before then to prep for their removal try searching for a post or thread by Landtank and heater lines. He was able to replace them but not easy. I believe he also divorced the two new lines and also may have loosened motor mounts and lowered the tail end of transmission for more room.

    Mine sit in place unused as scrowleys do.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.