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1998 K3500 rear brake line leaking.

Discussion in 'Chevy Trucks' started by 70monte, Aug 21, 2015.

  1. 70monte

    70monte Senior Member
    Messages: 468

    Line that goes from the fitting right behind the gas tank to the block mounted on the rear axle sprung a leak today. Does anyone know what size line this is? I'm thinking it's 3/16th but want to make sure.

    Does the gas tank have to come down to unscrew the line from the fitting behind it? Has anyone been able to remove the line without taking the tank down?

    Tank is about 3/4th full and I don't want to take it down if I don't have to as I really have no real good way to do this.

    I'm sure this is going to turn into a mess because I'm sure the fittings will not come loose. I've sprayed some penetrating oil on the fittings as well as a mixture of auto tranny fluid and acetone.

    Thanks for any ideas on fixing this problem.

    Wayne
     
  2. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,983

    So your saying the rubber flex hose is leaking? Just get her up in the air as high as you can and have at it. Is it 4 wheel ABS? Better to change the rusted lines now than in a snow storm.
     
  3. yukonslt3

    yukonslt3 Junior Member
    Messages: 10

    it may be a 1/4'' if its not a 3/16th
     
  4. rjigto4oje

    rjigto4oje PlowSite.com Addict
    Messages: 1,294

    I just purchased a set of stainless steel lines from a company called ss tube, found them on eba. 220 dollars shipped to the door nice peoduct
     
  5. 70monte

    70monte Senior Member
    Messages: 468

    No, it's the hard line that comes from the front of the truck and goes into the union that the rubber flex hose is attached to. There is a coupler that separates the part that I need to repair to the front run of line. This coupler is behind the gas tank so there is not easy access. You can see it if you look up from under the truck because it is between the gas tank and the frame. The rest of the line is attached to the inside of the frame.

    I will check out the company SS tube. Thanks.

    Wayne
     
  6. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,983

    That rear coupling is part of the rear flex hose. Cut the steel line off at the line nut. Remove the nut with a six point socket. Follow the line forward of the fuel tank. See if there is a union there somewhere. Or if the line is not rusted cut the steel line with a tubing cutter. Run anew line up behind the fuel tank to the rear connection. It really is not to hard to do. Do you no how to do a double flare? Do you have 4 wheel ABS? If you do and the anti lock unit gets air in it you will need a scanner that has brake bleed capabilities to do the job correctly.
     
  7. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,971

    Replace the WHOLE line from the front to the back. Either the s.s. option or they make an anti rust type line.
     
  8. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,983

    I was kinda waiten for his reply if he nows how to do flares and such. I no he should probably change them all, better to do it now instead of during a storm. And does he have time to order parts and wait or need truck on road now like most of my customers.
     
  9. 70monte

    70monte Senior Member
    Messages: 468

    Thanks for the replies. I do know how to do double flares and have the equipment to do so. I will try and take some pictures of what I'm talking about. The rear flex hose is a separate piece on this truck and is not part of the hard line that I need to replace.

    The piece that I need to replace is attached to the union that is between the fuel tank and the frame and screws into the block that the rear flex line screws in to.

    The lines toward the front of the truck still look good as they have undercoating sprayed on them. Even the line coming out of the union behind the fuel tank going toward the front that have no undercoating on them have no rust on them.

    This truck appears to only have front ABS.

    I'm going to try to take apart the lines today after work and see what happens. I may have to unscrew the line further up toward the front. Thanks again.

    Wayne
     
  10. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,971

    Just cut the line in a spot that's easy to get at and is not rusty, install a union coupler and snake the new line back.
     
  11. Plowtoy

    Plowtoy Senior Member
    Messages: 929

    Check with your local napa store. I heard that they are now offering SS lines for popular makes and models pre-bent.
     
  12. 70monte

    70monte Senior Member
    Messages: 468

    I did find some pre-bent kits on ebay in regular steel line and in SS for this truck. One kit is $190 for the SS and the other is $290 for the SS. I also may end up having to replace all of the lines mounted to the rear axle and going to the wheel cylinders because they look pretty rusted and I don't know if I can get the bleeders open on the cylinders which may cause me to have to put new wheel cylinders in it.

    I have been spraying all of the connections and bleeders the past few days with penetration oil to see if maybe I can get them open. I may just end up replacing everything depending on what happens but given my luck, things will go bad. Thanks again for the info.

    Wayne
     
  13. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,971

    190.00 for prebent line for a 98....wanna buy a bridge to? I got one real cheap.
     
  14. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,971

  15. 70monte

    70monte Senior Member
    Messages: 468

    That is the cheaper of the two stainless steel kits. These both supposedly have all of the brake lines for the truck but they still are very expensive.

    Most of the lines on the truck look okay, it's just every thing in the back that looks back, including the rubber flex line. I'm just trying to fix what is messed up right now.

    Thanks to the link.

    Wayne
     
  16. Randall Ave

    Randall Ave PlowSite.com Addict
    Messages: 1,983

    U have disc or drum in rear? I have a 98 c-2500 its still has drums in rear. Just run a new line all the way back, just feed it up in the frame by the fuel tank to the new flex hose. Then run new lines to whatever you have at wheel ends. The brake lines from auto parts store are gonna cost maybe 35 bucks.
     
  17. terrapro

    terrapro PlowSite Veteran
    from MI
    Messages: 3,874

    Buy a roll and replace all the lines now if you know how to double flare. Once one goes they all go shortly so why wait it's not that expensive $30-35 for a roll and $10 on fluid and usually you can reuse the fittings just spray penetrating fluid on them first. Literally the most time consuming part is bleeding the lines.
     
  18. 70monte

    70monte Senior Member
    Messages: 468

    My truck has drums in the back. I may try replacing all of the lines but I believe I have two different line sizes on different parts of the brake system so I would have to buy two rolls. I'm just hoping to get this repaired without draining the master cylinder. I'm going to tackle this on Friday on my day off and see what happens.

    The last truck I had to build brake lines for was a 1996 Ford F150 and the lines ended up snapping off at the wheel cylinders on both sides so it turned into a big mess because I almost could not get the wheel cylinders off.

    This chevy has more rust in the rear than that truck did so I'm sure something is going to go wrong. I've not had much good luck working on vehicles lately.

    Wayne
     
  19. averhoog

    averhoog Junior Member
    Messages: 10

    The lines will be 1/4 inch from the master to the rear axle flex line all the rest of the lines are 3/16 inch just replace from the master to the flex line on the back real easy you should replace everything and get it done then you don't have to worry about it
     
  20. averhoog

    averhoog Junior Member
    Messages: 10

    The lines will be 1/4 inch from the master to the rear axle flex line all the rest of the lines are 3/16 inch just replace from the master to the flex line on the back real easy you should replace everything and get it done then you don't have to worry about it