ABS Bleeding with JScan

[nositting]

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

yep, it looks like you may have stated this earlier, sorry about that! i’m hoping that the app knows you just completed the first side, and the second time you run the scan, the prompts switch to say do the opposite side but maybe that’s a lot to ask? lol. seems like, if both sides are needed, it should take you through all four wheels, no?

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[Medsker]

We ran it three times and it said to do the right side every time. When you've done the right rear it says something like "ABS Bleed Done". You could in theory run it twice through and do the left side. I'm interested to see what you figure out when you run it.

 

[nositting]

yep, i probably won’t do until late spring/this summer when i do the pads but will check back afterwards.

 

[Medsker]

I was out driving my Jeep today and slammed on the brakes and they still aren't where they need to be. I stopped by the shop that installed them and they are going to look at it next Wednesday when I take it in for some other stuff. I figure the Delta brakes should lock up when I slam the brakes and it didn't. Just stopped quickly, but didn't lock. My stock brakes would lock the tires up when I slammed on them and these should too.

The saga continues. I'll let you know what they figure out.

 

[Jeep Wick]

I don't know what's different about the XR/High Tide brakes, but they are dramatically better than what I had on the Rubicon. Might be worth looking at an oem upgrade.

 

[Medsker]

That's a good thought but after spending $3000 on new brakes I just want them fixed.

 

[Tooth]

I was out driving my Jeep today and slammed on the brakes and they still aren't where they need to be. I stopped by the shop that installed them and they are going to look at it next Wednesday when I take it in for some other stuff. I figure the Delta brakes should lock up when I slam the brakes and it didn't. Just stopped quickly, but didn't lock. My stock brakes would lock the tires up when I slammed on them and these should too.

The saga continues. I'll let you know what they figure out.

I installed the Delta brakes about 300 miles ago and mine are the same as what you describe. I bled them multiple times, including ABS. They are substantially better than the stock sport brakes, but not omfg I need a tissue better. I have not tried to lock up tires, but they stop ok. I’m on 37” MT tires and a moderately heavy Jeep. It has improved as I put more miles on the pads, but it’ll never stop like a Miata.

 

[58Willys]

Are you bleeding system correctly? FSM procedure is to , preferably pressure, bleed hydraulic brake system same as any non ABS system; then bleed ABS system, then re-bleed hydraulic system again.

Also, may take a few miles for new components to bed in and perform well; although pedal should be firm from the outset.

 

[Yawnie'sPapa]

Open screw, pedal to the floor hard and fast, close screw, let pedal up, repeat. "

If your master cylinder isn't very old - you'll probably be ok. But if it's got any age, it's risky.
No reason to press pedal hard and fast. I'll never ever use that method on an older master cylinder - say, over 3 or 4 years old especially if it's not been flushed on a regular basis.

I'm trained by Bendix, Wagoner and other companies in brakes and have done hundreds of brake jobs and other brake service over the years. I worked my way through college (automotive) doing brakes, suspension and steering.
There's a lot of shade-tree old school stuff out there that's trying to be carried forward into the now - and it can be risky to say the least.

If the master cylinder has any age to it, the cups have been stopping in relatively the same place for a long time. Debris, acids, even some sludge, can form at the point those cups stop in the cylinder.
Shoving the master cylinder piston cups hard and fast clean to the bottom means you are shoving past those rings of crud, and if you go hard to the bottom, if you've shoved some of that into the end wall of the cylinder, the cups are forced into it hard and fast.
I've seen a whole lot of vehicles end up needing new master cylinders after some of the old way bleeding was done. Granted, they weren't in perfect health, but they failed almost right after the bleeding process of slamming hard and fast to the bottom where otherwise they might have gone a couple more years with some every-two-year flushing and some care.

I see someone on page one of this thread also mentioned something about the risks with some of these processes - and said flame suit on - they won't get any flaming from me, I agree. Decades of experience support my lines of logic and using methods other than slamming the brake pedal down.
Besides, if you push it down hard and stop and then close the bleeder, depending on how the bleeder end of things is configured - hose size and length and so on, air can actually go back in - even 50 years ago the guy doing the pedal pushing would call out just before it hit bottom so you could close the bleeder while there was still pressure outward. Worked a whole lot better, faster, easier bleeding (but still ran into master cylinder issues at times - pressure bleeding or vacuum bleeding is best)

As the man on page 1 said "flame suit on" but then I have no fear because I can go right to my college texts and training manuals to support what I suggest ?

 

[andy29847]

If your master cylinder isn't very old - you'll probably be ok. But if it's got any age, it's risky.
No reason to press pedal hard and fast. I'll never ever use that method on an older master cylinder - say, over 3 or 4 years old especially if it's not been flushed on a regular basis.

---------------------

As the man on page 1 said "flame suit on" but then I have no fear because I can go right to my college texts and training manuals to support what I suggest ?

I googled "Bendix brake manual" and found this:

I'll concede that the manual does not say "hard and fast." I'd also like to point out that even when pressing the pedal slowly, the master cylinder cups would go past any ridge of crud that might have been formed during use. I think "short stroking" the brake pedal when bleeding brakes is a procedure left over from when the material that master cylinders were made of was less resistant to corrosion.

The main point of my previous post was to say that you should not pump the brakes before bleeding. Pumping can cause air bubbles in the fluid.

When I bleed my brakes, I run the tube from the bleeder up and over another part of the vehicle and then down to my catch container. This loop keeps air away from the bleeder. This is a different way of complying with the Bendix instructions that say keep the far end of the bleeder hose immersed in fluid

 

[Medsker]

Great information guys. It is completely logical and makes sense to this engineer. It looks like I'll have to change my methods. I hope I didn't damage the master cylinder playing around. I did bleed them correctly as far as "regular bleed", "ABS bleed", and then "regular bleed" again. Mine went more like regular, regular, regular, ABS, ABS, regular, regular, ABS, regular, and so on ?

 

[Tooth]

I was out driving my Jeep today and slammed on the brakes and they still aren't where they need to be. I stopped by the shop that installed them and they are going to look at it next Wednesday when I take it in for some other stuff. I figure the Delta brakes should lock up when I slam the brakes and it didn't. Just stopped quickly, but didn't lock. My stock brakes would lock the tires up when I slammed on them and these should too.

The saga continues. I'll let you know what they figure out.

@Medsker what did the shop conclude?

 

[Medsker]

what did the shop conclude?

Thanks for asking! They bled the brakes: traditional, ABS, ABS, traditional. They said they got a little air out of one of the corners but I didn't think to ask which one. They feel harder around town but I haven't been to a stretch of road I feel safe to lock them up and see how they do.

After all the bleeding they have done and I have done I think they are as good as they are going to get.

 

[Tooth]

Appreciate the update. I bled mine again after reading through this last week. I tried hard stops and felt mild ABS feedback, so probably as good as they’re going to get. After watching that Northridge video of the Jeep stopping, I would say it’s comparable.

 

[Medsker]

Thanks for the confirmation. i'll take it out next week and do some panic stops and see how they are.

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