ABS Bleeding with JScan

[Jubi351]

Just put a piece of 2x4 under the brake pedal to avoid over travel in the MC while bleeding.

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[gsbrockman]

Thinking a bit outside of the box here……but couldn’t one perhaps find a gravel road, determine a safe speed, jam on the brakes a few times, then perform a manual bleed at all four corners, and repeat X of times?

 

[nositting]

A shop just installed Teraflex Delta brakes. They got the brakes on but the pedal is a little spongy and I want to try to bleed them myself rather than take it back. If I can't figure it out then I'll take it back in.

I know I need to bleed the ABS system so I ordered the Bluetooth module and SGW plug cable adapter. They will be here Saturday. My question is does the JScan walk you through this procedure? I can't seem to find a lot of info on this. I'm not the best at searching though. If it doesn't walk you through it then what is the procedure? I know I have to remove my taser, bleed the brakes, do the ABS bleed, and then bleed the brakes again but I'm not sure on the ABS bleed part. Any help would be appreciated.

I played with the demo on the JScan but it didn't show anything about bleeding the ABS system.

Thanks in advance!

i recently posted questions on this as well. the security bypass extension cables are a must. i do a lot of my learning from youtube and unfortunately, i haven’t found a walk through for this in reference to the JL. i plan on doing this in the spring. i’m sure a regular brake bleed would be sufficient, but i like learning new stuff. please post any info you can as it sounds like others may be interested. thx!

 

[Medsker]

So I just tried this without success. The ABS went off like it was supposed too and I bled them. The JScan walked me through it but it only had me do the right front and then the right rear and then said the test was over. It didn't tell me to do the left side. Is this normal? After the ABS scan I took it for a drive and there was no change so I came home and did the ABS bleed a second time. Then bled the brakes the old fashion way and still have a soft pedal.

Any ideas? I can take it back to the install guys but I don't know how successful that would be because it seems they didn't know you have to remove the taser to ABS bleed.

I'm very frustrated Any ideas would be appreciated.

 

[Medsker]

After some research it looks like it does only do the right side during the ABS bleed.

So I went back out and bled the brakes again. My wife is gone so I used the speed bleeders. This is the first time I've used them. What a great idea! It was weird when I bled the back brakes the pedal wouldn't go to the floor it would only go down about 2/3 of the way. The fronts went to the floor like I'm used to. I double checked the rear bleeders were opened all the way when I was bleeding them.

I'm not sure where to go from here. After bleeding them this time they did seem firmer but when I slammed on the brakes they still didn't lock up they just slowed down fast.

I think because it did get a little better I'm going to try doing the ABS bleed again and then bleed the brakes one more time. I'll have to wait for the wife to come home to do the ABS bleed.

Any other ideas?

 

[five9dak]

Everyone who hasn't experienced it will say its not necessary, but it definitely CAN be, even if you don't do anything wrong. Happened to me. I have worked on probably 50 brake systems before this one without running into this.

My dealership charged me half an hour of labor to do it with their scanner.

 

[andy29847]

Mr. Blaine is the mechanic guru over on a TJ forum. He writes this about bleeding brakes (note the last 2 lines): "
I use and prefer the manual method. There are several misconceptions in the above though. First, never use line that isn't clear. You need to see exactly what is happening at the end of the bleed screw.
Never use an open end wrench, in fact, it's not even recommended to use a 12 point box end wrench. It is far too easy for the wrench to tip over sideways and round off the hex due to how narrow most of them are nowadays. If you don't have the right box end, get a 6 point socket and break the bleeder loose so you can use the open end on it. Don't forget and try to tighten it without the 6 point.

No need for fluid in the container. Go to any working brake system and open a bleed screw with the master cylinder reservoir cap off. Fluid will run out and if fluid is running out, air is not going in so no need to keep the hose submerged in brake fluid not to mention that the first time you open the bleeder, all the air in the empty hose would go into the caliper if that is how it worked. Fortunately it isn't.

To be clear, fluid isn't running out. It is being forced out by hydrostatic pressure and the bleeder is at the very top of the wheel cylinder so the only actual amount of air that could really get in is the amount in the bleed screw itself.

If you use clear hose and do a few pedal pushes, you'll see very quickly that when you stop, the fluid in the hose starts running into the container and leaves you with air just past the end of the bleed screw. Again, old wives' tale about submerging the end of the tube. For it to work due capillary action, the tube needs to be much smaller and the fluid needs to have a much higher viscosity. The viscosity is not variable and small tube won't fit over the end of the bleed screw easily.

If you need more than 5-7 bleeds per corner, stop and find the problem because flushing more fluid down the drain isn't going to fix the problem.

Do not ever do the pump and hold method, all that does is aerate the fluid.
Open screw, pedal to the floor hard and fast, close screw, let pedal up, repeat. "

 

[Medsker]

Thanks for the ideas! The last two lines make sense to me. I just bought a pneumatic bleeder from Harbor Freight I thought I would try. This would eliminate any aeration in the pedal pumping.

My wife gets home in about an hour so I'll give it another go then. ABS bleed first and then regular bleed. If it doesn't work this time I'm going to assume something else is wrong and take it somewhere professional.

 

[Medsker]

I bled them one more time and that seemed to do the trick. I have a hard pedal again

The only weird thing left is when I lock them up going around 35 mph the Jeep tires squeal for a split second, the ABS kicks in, and the pedal goes 3/4 of the way down. The first two are normal; I'm not sure about the last one. The pedal is still hard when it goes down so I'm not too worried about it but any ideas as to why this is happening would be appreciated.

Thanks for all the help in the thread from everybody!

 

[Rogersocal]

After some research it looks like it does only do the right side during the ABS bleed.

So I went back out and bled the brakes again. My wife is gone so I used the speed bleeders. This is the first time I've used them. What a great idea! It was weird when I bled the back brakes the pedal wouldn't go to the floor it would only go down about 2/3 of the way. The fronts went to the floor like I'm used to. I double checked the rear bleeders were opened all the way when I was bleeding them.

I'm not sure where to go from here. After bleeding them this time they did seem firmer but when I slammed on the brakes they still didn't lock up they just slowed down fast.

I think because it did get a little better I'm going to try doing the ABS bleed again and then bleed the brakes one more time. I'll have to wait for the wife to come home to do the ABS bleed.

Any other ideas?

A few things i have read say it should do both Driver side and Pass side. thats strange. But im wondering how to switch sides in Jscan or if its the same just which side you open is where it bleeds

 

[Medsker]

I don't know the answer. JScan specifically says right front and right rear. Everything works now so I guess only doing the right side works.

 

[Rogersocal]

https://www.wranglerforum.com/threads/jscan-abs-bleeding-procedure.2445554/

In that link is a detailed explanation of the ABS Bleed. I think when it does the front it does both side at the same time. So starting on the driver side Then ending on the Pass side running the absbleed 2 times to perform it

 

[nositting]

msdsker and rogersocal, thank you so much. i thought i could figure this out however having a protocol to follow really helps with my confidence with this. thanks again!!

 

[nositting]

in the example provided, it looks as if you do one side and then go to step 3 which is to run the program again so i’m wondering if the second time you run through it, it pumps the other side?

 

[Rogersocal]

in the example provided, it looks as if you do one side and then go to step 3 which is to run the program again so i’m wondering if the second time you run through it, it pumps the other side?

I think it pumps both front at the same time so running it again you just choose the side you wish to bleed.

Ill be completing this in a couple days if it doesn't rain again

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