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    Quote from Bigdog

    Explain the procedure for bleeding the ABS....do you bleed it after the 3 wheels and do you need to pump the brakes to bleed the ABS? Thanks

    When we bleed the brakes here, we start with the rear caliper first. Then we do the passenger side front and then the drivers front. Last is the ABS module itself, there is one rubber nipple on it, pop off the nipple and use a 10mm wrench to loosen the bleed, after bleeding that nipple, tighten the nipple back with the 10mm wrench and clean any extra brake fluid that may have dripped out off of any painted surface.

    Quote from Bigdog

    I can't ever remember a car mechanic talk about bleeding the ABS

    Since the Slingshot uses a ABS module from a car, but they only use 3 of the 4 ports is the reason that you have to bleed at the ABS module. In most cars all 4 ports would be used, so you can just bleed all the air out at the calipers.


    Hope that helps,
    Dave

    Thanks Dave good info...now that 3-4 thing makes sense.


    Do you need to pump the brakes to bleed the ABS unit or just open it? I'm thinking since it's lower than the master......fluid should gravity feed down to the ABS. But I've been wrong once before... started on the day I was born and hasn't ended yet.

    It's my understanding (I'm old school)) the ABS has to be open to allow for correct bleeding of that system. The pulsating (antilock) comes from that metering device and by only hooking up the on board computer, that opens and clears the way for a complete bleeding of air to flush thru.
    So much for the old bench bleeding.

    Quote from nipper51

    It's my understanding (I'm old school)) the ABS has to be open to allow for correct bleeding of that system. The pulsating (antilock) comes from that metering device and by only hooking up the on board computer, that opens and clears the way for a complete bleeding of air to flush thru.
    So much for the old bench bleeding.

    There are a couple circuits for fluid to travel inside the ABS module. The standard fluid path (while the ABS is not engaged) does not require anything to be energized for that path to be open, otherwise if there was an electrical failure you would lose your brake pressure, and that would be a bad thing. When the ABS is activated though, the ABS system does open up a pathway to an accumulator to release some pressure and then can also open up another pathway to the ABS pump which returns brake pressure back to the master cylinder. In order to get air out of that pathway, the ABS would need to be activated for fluid to travel that circuit. That being said though, that system returns pressure and fluid back to the master cylinder and the air should go back with any fluid and simply go into the reservoir since air is going to travel to the highest point in the system. The problem we typically have seen with the ABS module needing to be bled is that the empty 4th line that is capped off on the ABS module is the highest point on that dead leg, so even if the ABS module is activated, any air in that leg can not travel back down into the ABS module and return back to the reservoir. Also since any air in that 4th dead leg would be part of the normal brake pressure circuit, it will make the brakes feel "mushy" or soft, which is one of the complaints we often hear with the Slingshots.


    That is why bleeding the dead port on the ABS module without activating the ABS works in most cases since it is the high point on that 4th dead leg, although I am sure there are going to be exceptions.


    Hope that helps,
    Dave

    Quote from Dave@DDMWorks

    There are a couple circuits for fluid to travel inside the ABS module. The standard fluid path (while the ABS is not engaged) does not require anything to be energized for that path to be open, otherwise if there was an electrical failure you would lose your brake pressure, and that would be a bad thing. When the ABS is activated though, the ABS system does open up a pathway to an accumulator to release some pressure and then can also open up another pathway to the ABS pump which returns brake pressure back to the master cylinder. In order to get air out of that pathway, the ABS would need to be activated for fluid to travel that circuit. That being said though, that system returns pressure and fluid back to the master cylinder and the air should go back with any fluid and simply go into the reservoir since air is going to travel to the highest point in the system. The problem we typically have seen with the ABS module needing to be bled is that the empty 4th line that is capped off on the ABS module is the highest point on that dead leg, so even if the ABS module is activated, any air in that leg can not travel back down into the ABS module and return back to the reservoir. Also since any air in that 4th dead leg would be part of the normal brake pressure circuit, it will make the brakes feel "mushy" or soft, which is one of the complaints we often hear with the Slingshots.
    That is why bleeding the dead port on the ABS module without activating the ABS works in most cases since it is the high point on that 4th dead leg, although I am sure there are going to be exceptions.


    Hope that helps,
    Dave

    Yes ! thanks Dave@DDMWorks, finally somebody with a lot more credibility then little ole me , confirms you can get rid of mushy brakes (most times) by bleeding that fourth port ! I once was trying to explain to somebody named blitzekr... over on the dark side, how we have been very successful in just doing a ten mph skid with the right front wheel off the pavement and in the gravel , (verses Noel,s high speed brake jamming fix) which will immediately activate your ABS , then bleeding that port , but he then reiterated with five bold lines of , YOU MUST ACTIVATE THE ABS WITH DIGITAL WRENCH , over and over again ! so I just left it at that and played dumb , but chuckled like hell when @Tripod replied to him , so lets be clear, Do I have to activate my ABS with digital wrench ?

    Quote from MiM

    Everything you said @Dave@DDMWorks makes no sense on my helicopter... You sure you know what you're talking about? 8|


    Not applicable to Bumper boats, unicycles or Helicopters, sorry I didn't put that disclaimer in there.

    Quote from kev

    Yes ! thanks Dave@DDMWorks, finally somebody with a lot more credibility then little ole me , confirms you can get rid of mushy brakes (most times) by bleeding that fourth port ! I once was trying to explain to somebody named blitzekr... over on the dark side, how we have been very successful in just doing a ten mph skid with the right front wheel off the pavement and in the gravel , (verses Noel,s high speed brake jamming fix) which will immediately activate your ABS , then bleeding that port , but he then reiterated with five bold lines of , YOU MUST ACTIVATE THE ABS WITH DIGITAL WRENCH , over and over again ! so I just left it at that and played dumb , but chuckled like hell when @Tripod replied to him , so lets be clear, Do I have to activate my ABS with digital wrench ?


    If you really want to make sure, go out and activate the ABS a couple times to get fluid to move through those circuits. However, most of the time the air that is in the dead 4th leg can be removed by bleeding the closed off nipple on top of the ABS module. I am not going to say that in every circumstance it will always work, since I am sure there is going to be some person(s) that it will not. That being said, bleeding that 4th dead leg is relatively easy to do, requires no special tools and in our experience has made a significant difference, so why not try it and see if it works? If it doesn't then go down the path of using a digital wrench, etc.

    Quote from Dave@DDMWorks

    Not applicable to Bumper boats, unicycles or Helicopters, sorry I didn't put that disclaimer in there.

    If you really want to make sure, go out and activate the ABS a couple times to get fluid to move through those circuits. However, most of the time the air that is in the dead 4th leg can be removed by bleeding the closed off nipple on top of the ABS module. I am not going to say that in every circumstance it will always work, since I am sure there is going to be some person(s) that it will not. That being said, bleeding that 4th dead leg is relatively easy to do, requires no special tools and in our experience has made a significant difference, so why not try it and see if it works? If it doesn't then go down the path of using a digital wrench, etc.

    It worked for me.