Brake Bleeding Question

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  • leehljp
    Just me
    • Dec 2002
    • 8429
    • Tunica, MS
    • BT3000/3100

    Brake Bleeding Question

    In an earlier post here the subject of braks made me think of replacing the front rotors and brakes on my '95 Ford Ranger.

    I have a Brake "Bleeding" Question. I have replaced the rotors, all went well, the calipers are back on. I pressed (with a C-clamp) the pistons back in about 1/8 to 3/16 inch and installed the pads with no problem. I loosened the cap on the brake fluid reservoir but no fluid overflowed when I did that. No brake fluid leaked out at the wheel either.

    My question is: IS it necessary to bleed the lines if no fluid leaked?
    Do I want to open the bleeder nozzle?
    How much and when do I know is enough brake fluid leaked out?
    What am I missing? What do I look for as to how much?
    How does air enter?
    IF no air enters, is it necessary to bleed the line?


    About 35 years ago, I had all kinds of trouble bleeding a line, but at that time fluid leaked out the pistion when changing drum brakes. My truck is in Dallas with my Son-in-law and I am here replacing the rotors/brakes. The back brakes and drums were replaced about 7 years ago and it has about 15,000 miles since then, so the rear changing are not necessary. The front has about 140,000 miles but certainly not badly worn for the miles.

    I will be here until Monday, but would appreciate an answer by Sunday evening if it is possible.

    Thanks
    Hank Lee

    Experience is what you get when you don't get what you wanted!
  • LinuxRandal
    Veteran Member
    • Feb 2005
    • 4889
    • Independence, MO, USA.
    • bt3100

    #2
    If your replacing just the pads and rotors, then no. I have a 94 Ranger and worked in a garage for a while. You WILL need to PUMP THE BRAKE PEDAL, before moving the vehicle or get a surprise, and you should do that when you get it, before you turn the key.
    If you have to replace a collapsed brake line, or caliper (if seized), then you will need to bleed it.

    The other questions deal with after air has entered (replacing other parts). There are both pressure and vacuum bleeders that are supposed to make it a one man job *a web search will turn up a homemade device using an inexpensive pump sprayer, into a pressure bleeder*, but we still did two man, as we liked to know the feel of the brakes (could lead to finding other issues). I'd recommend finding some video's on Youtube as it tends to help better then explaining the process (watch for air/spitting, then go a couple or three more times after stopped, don't run out of fluid) if you need to bleed.
    She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.

    Comment

    • frumper64
      Established Member
      • Feb 2004
      • 376
      • Garland, Tx, USA.

      #3
      Hank, I think you will be fine not bleeding the brakes. At some point in time, you should probably bleed them enough to push out the old fluid and replace it with new, since brake fluid is hygroscopic and absorbs water. That is a separate issue though from replacing the pads and rotors. Better get it done today - it's supposed to get cold tomorrow here in Dallas and laying around on cold concrete isn't much fun.
      Last edited by frumper64; 02-14-2015, 05:45 PM. Reason: spelling error
      Jim
      64sedan_at_gmail.com

      Comment

      • leehljp
        Just me
        • Dec 2002
        • 8429
        • Tunica, MS
        • BT3000/3100

        #4
        THANKS fellows! LR, I plum intend to pump the brakes a bunch of times! I don't want any surprises for my son-in-law when my grandson is with him as they go for an overnight campout.

        The changing of the rotors did have one little surprise. The my rotors had seals for the inside of the hub and protecting the bearings, but they didn't show any at the O'Reilys near us. I had already purchased them and was about to install them when I noticed the new ones didn't have them. The fellow at the parts store (assist. mgr) said it didn't show for my '95 truck. I removed the seals easily enough and placed them on the new ones.

        I haven't packed a bearing in ages. It was fun doing it again!

        I looked at a youtube and somewhere in mpcs post (or maybe somewhere else) I read/heard that there were a few non-standard or oddball fittings for the 94-96 era Rangers - as it related to the anti-lock brake system.

        Thanks again.
        Last edited by leehljp; 02-14-2015, 06:16 PM.
        Hank Lee

        Experience is what you get when you don't get what you wanted!

        Comment

        • atgcpaul
          Veteran Member
          • Aug 2003
          • 4055
          • Maryland
          • Grizzly 1023SLX

          #5
          My gear head BIL actually balked when I told him I flushed the brake fluid. He said he never does it because of the risk of introducing air. I don't buy it, but what do I know? He does rebuild classic cars and builds OCC style bikes as a hobby, though.

          Anyway, I did a gravity bleed. I couldnt find a decent review on an inexpensive vacuum bleeder. I got a clear hose that fit over the little nipple at the brake. The other end of the hose went into an empty water bottle. While the brake reservoir cap was closed, I loosened the bleeder nipple and my dad pumped the brake. After a few pumps, I'd close off the nipple and he'd top off the reservoir. We repeated this until the fluid ran clear and we went from brake to brake. My mid-size SUV took 1 quart of fluid. I think it's really a two person job and doesn't take a long time. The person bleeding the brakes just has to be sure air doesn't seep back into the lines.

          Comment

          • capncarl
            Veteran Member
            • Jan 2007
            • 3564
            • Leesburg Georgia USA
            • SawStop CTS

            #6
            Do pump up the brakes well before moving the vehicle. My old neighbor did a quick disk and pad change on his front wheel drive 90s era Chevy and didn't pump up the brakes. The next morning his wife backed out the driveway and the brake petal went to the floor, she put the other foot on the petal thinking that would help and hit the accelerator. The car jump the ditch on the other side of the road and bent in half, wrinkled the top and jammed all 4 doors. Insurance value was nothing so he red neck straightened the frame. What a mess.

            Comment

            • mpc
              Senior Member
              • Feb 2005
              • 979
              • Cypress, CA, USA.
              • BT3000 orig 13amp model

              #7
              I do a one-man version of what atgcpaul posted. I use a clear hose on the bleeder nipple and bend it into an inverted "U" arch about 6 to 10 inches above the nipple. Twist tie or tape it to the suspension spring or other car part to hold it, the other end gets taped inside a jar. This way, when I push the pedal down, I just hold the pedal for a few seconds so any air bubbles in the fluid can rise to the top arch... any fluid that back-flows into the bleeder as I then release the pedal will be air-free. I do this until I see light-tan coloroed fluid in the hose - i.e. new fluid - replacing the dark brown old stuff.

              On some cars it helps to smear a bead of something all the way around the base of the bleeder nipple once it's loose. Some bleeders will let air past the sloppy fitting threads as you release the brake pedal. The various gasket maker/sealer goops work well, as does spark plug anti-sieze compound. Just something to act like window caulking.

              I never push the caliper in without opening the bleeder nipple to dump the pressure overboard. Some ABS units can be damaged by back-pressure, the rubber "cups" on the master cylinder pistons can be damaged too. This also avoids the issue of pushing the brake fluid back to the reservoirs and possibly making them overflow.

              mpc

              Comment

              • JimD
                Veteran Member
                • Feb 2003
                • 4187
                • Lexington, SC.

                #8
                It is not necessary to bleed the brakes when you haven't opened the system. If you replace a caliper or line, you have to bleed. It is a good idea to change the fluid, however. BMW recommends it ever 2 years and does it while you are in the "free" maintenance period. I like to use the "Motive" pressure bleeder I gave my son. It makes it an easy one person job. I don't put brake fluid in the Motive, I use it to pressurize the resovor. I have to refill between wheels but I don't have to clean out the Motive.

                Comment

                • woodturner
                  Veteran Member
                  • Jun 2008
                  • 2047
                  • Western Pennsylvania
                  • General, Sears 21829, BT3100

                  #9
                  Originally posted by leehljp
                  I have a Brake "Bleeding" Question. I have replaced the rotors, all I pressed (with a C-clamp) the pistons back in about 1/8 to 3/16 inch and installed the pads with no problem.
                  You will see from the responses that there are differing opinions on how to do this. My opinions as an engineer and mechanic are explained in this post.

                  Pushing the calipers back without opening the bleeder valve is not a good idea, as it will push debris back into the brake line and eventually cause the calipers to fail. The "proper" procedure is to open the bleeder, then push back the caliper piston so the old fluid is discharged through the bleeder. Better yet, replace the calipers at each pad change - both AZ and AA offer lifetime warranty on calipers, so it's free to replace them after the first time.

                  My question is: IS it necessary to bleed the lines if no fluid leaked?
                  No, but it's good practice to bleed the lines every pad or shoe change to flush the fluid that has absorbed water and will cause the brake lines to rust.

                  When I change pads, I follow the manufacturer's recommended procedure:
                  1. Change the caliper
                  2. Change the pads
                  3. Resurface or replace the rotor (necessary so that the new pads will seat correctly - if the rotors are in good shape, this is just using a sander to restore the cross hatching)
                  4. Seat the brakes( Make several hard stops, enough to heat up the rotors and pads enough to smell a bit and transfer some brake material to the rotors)

                  YMMV, you may get away with doing less, etc.
                  --------------------------------------------------
                  Electrical Engineer by day, Woodworker by night

                  Comment

                  • LinuxRandal
                    Veteran Member
                    • Feb 2005
                    • 4889
                    • Independence, MO, USA.
                    • bt3100

                    #10
                    Where the Rangers, as well as other Fords tend to have issues is the brake line to the calipers. They have a mount that is made of metal and surrounds the outside of the brake line. As it rusts, it collapses the enclosed section while swelling up the parts around it.
                    Debris should NOT be in the brake system, but where I have found it, is after that fitting and before the caliper, where the fitting acts as a stop. When that line fails I've found that it can be a pain to remove, due to rust at all the connections and the caliper gets replaced, standard. (did my passenger side six months ago on a then 20 year old truck)
                    Is it better to bleed them and replace the fluid ocassional, yes. (even see some using different colors so they can tell when the new is in the system) But if your unsure of yourself (and you have already done the brakes), it is a risk, that you could get air into the system and IMHO, not worth it. Personally I would say keep it driveable and when you take it in for a service on something you don't want to do, then pay to have the fluid replaced. (piece of mind money, verses what your not comfortable with)

                    I went looking and here are a couple of things showing the DIY, motive style systems.

                    A DIY Brake Bleeder Using Either Pressure or Vacuum: A brake bleeder is a handy one man device to change the hydraulic fluid in your car or motorbike. Using either pressure at the reservoir or vacuum at the bleed nipple, turns this fiddly chore into a one man operation, removing the need to have some…


                    On the damaging the abs comment, this is front brakes (rotor not drum), on a vehicle with RABS (rear only 93-97), so it doesn't go through the ABS system (would have to be pushed quite a ways back and then through the outgoing lines through the RABS sytem to the rear).
                    I understand the worry about introducing air and not doing it (see it frequently and was common by the old timers I knew, people in their 70's who lived by the if it ain't broke, don't fix it). This was one thing that came up when we were discussing pressure, verses vacuum systems. The inexpensive hand vacuum units, people thought would fail first and give problems and no one wanted to try a separate vacuum pump, for fear it would pull too much as cause the fluid to run out before it could be filled.
                    She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.

                    Comment

                    • leehljp
                      Just me
                      • Dec 2002
                      • 8429
                      • Tunica, MS
                      • BT3000/3100

                      #11
                      I wish I had asked this question yesterday! OK, I am down to LRs response since it is done. I haven't tested it yet. As soon as I got the tires back on, the family was all ready to go out and eat - Japanese food by a Japanese cook. Very good.

                      I will check the brakes in the morning and pump them up. Test them going around neighborhood blocks, then to local streets, then onto some major streets. The next checkup, I will have them change the brake fluid.

                      Learned a lot. Saved a lot, but not sure if it was worth it at this point. Labor is about $250 to $300 both here and in MS for rotors and brake pad installs. That price is worth it if it is not done right by the owner (me).

                      I will report back tomorrow night.
                      Hank Lee

                      Experience is what you get when you don't get what you wanted!

                      Comment

                      • jdon
                        Established Member
                        • Feb 2010
                        • 401
                        • Snoqualmie, Wash.
                        • BT3100

                        #12
                        On some cars it helps to smear a bead of something all the way around the base of the bleeder nipple once it's loose. Some bleeders will let air past the sloppy fitting threads as you release the brake pedal.
                        Great tip! That's been frustrating me for years... doh!

                        Comment

                        • JimD
                          Veteran Member
                          • Feb 2003
                          • 4187
                          • Lexington, SC.

                          #13
                          I've never even heard of replacing a caliper unless it leaks. I've never done it in 40 plus years driving and maintaining my own cars. I've never read of somebody doing it as a normal practice until now. I've never replaced a caliper. I replaced a wheel cylinder on my 66 mustang years ago and had the bleeder valve blow out (bad casting). That is probably a one time experience but I don't think it would be wise to replace calipers that work fine. It is possible to get a bad new one. If you flush fluid occasionally, the caliper should outlast the rest of the car.

                          The point about the fluid in the caliper is what needs replaced is valid. But opening the bleeder while you push the caliper open for the new pads seems like another bad idea. It might get some bad fluid out but you can easily do that after everything is back together. That fluid will remain closest to the bleeder valve. If you open the bleeder while you are still replacing pads, you will get brake fluid all over and potentially on the new pads. You will also get air in the lines. Just not the right time to bleed.

                          If it matters, my degree is in mechanical engineering and I've done a fair bit of mechanic work on cars including engine and transmission rebuilding. I think my comments are more common sense, however.

                          Comment

                          • capncarl
                            Veteran Member
                            • Jan 2007
                            • 3564
                            • Leesburg Georgia USA
                            • SawStop CTS

                            #14
                            Up until just reasonly I would agree with JimD! .....But with the near catastrophic failure of the rear calipers on my 2004 Ford F-150 I'd say change the calipers. An educated person could say that the manufacturer has engineered this part to perfection, but of all sites singing phrases about engineering perfection, what with table saw switches that fail in the on position, plastic slides and guides that fail, belts that fail and pulleys that you can't get off? Go ahead and change the calipers, you have already got it jacked up. I can vouch for Fords caliper lack of engineering!
                            capncarl

                            Comment

                            • woodturner
                              Veteran Member
                              • Jun 2008
                              • 2047
                              • Western Pennsylvania
                              • General, Sears 21829, BT3100

                              #15
                              Originally posted by JimD
                              I've never even heard of replacing a caliper unless it leaks. I've never done it in 40 plus years driving and maintaining my own cars. I've never read of somebody doing it as a normal practice until now.
                              It's normal practice when a shop does a brake job, but part of the reason shops replace everything is that they don't want call backs. I do it because it is the "right" way to do it and I don't want to have to redo the job.

                              Climate is a factor as well - around here, in the snow belt, the practical life of a caliper is a year or two. It appears you may be in an area that does not get snow, so it may not be required in your area.

                              The most common failure mode is that the pistons stick, causing the brakes to drag. I don't know that I have ever had a leaking caliper, though I suppose that can happen also.

                              Another point that I forgot to mention is that the sliding pins should be lubed at least every pad change. Stuck sliding pins is another common failure, especially up here in the frigid North. It's the road salt and temperature changes that seem to cause all these problems.

                              If you open the bleeder while you are still replacing pads, you will get brake fluid all over and potentially on the new pads.
                              I've never had a problem getting brake fluid on the new pads, not sure why that would even be an issue. The process is open bleeder, push back piston, close bleeder, remove caliper, remove old pads, clean assembly with brake cleaner (if caliper is not being replaced), THEN unpack and install new pads.

                              As noted, the problem is that the rust and debris particles get pushed "upstream" and cause problems with the proportioning valves and ABS - that's why it is so important to open the bleeders before pushing back the pistons. If your vehicle does not have a valve in the brake line at the caliper, this may not be as significant an issue - but it is definitely an issue on Ford and Chrysler products.
                              --------------------------------------------------
                              Electrical Engineer by day, Woodworker by night

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