brake fluid flush question

[nositting]

i’ve searched threads regarding brake fluid flushing however the majority of what i’ve read is that you need a scanner when flushing the jl due to abs. have others been successful flushing without having trouble with the abs? i have a motive bleeder with appropriate cap and would like to try (no scanner). TIA

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[Some Random Guy]

I flushed without worrying about ABS or the clutch cylinder. My assumption is that it will be fine because I wasn’t flushing bad or old fluid. If I had been closer to a maintenance interval I’d probably flush then drive a month, then flush again. Still less time/money than dealing with a shop. People go 100k without ever flushing their brake fluid, so I think some residual is ok as long as it isn’t contaminated.

 

[nU7OuxIx]

I've never flushed my fluid unless I opened the line. I've only done that when rebuilding my YJ. I think a lot of dealers use scare tactics to have them flush the lines every x months.

I'll have to look up what the recommendation interval is. I'm trying to stick with it all with the Jeep. When I do have to flush, I'll most likely order a dongle and jscan license. I think that's the cheapest way you can pulse the abs.

If you're just flushing though, I wonder if you can open a bleed screw and slowly fill the reservoir so no air is introduced into the system, while a steady stream of fluid just leaks out.

 

[NWJeepr]

It is good practice to flush brake fluid in general. People who never do....well, water is also an effective hydraulic fluid...until it boils. Fluid becomes acidic as time goes on and it collects moisture and that corrodes the system from the inside out. Unless specified sooner, I don't like to go beyond 5 years in any of my vehicles.

It is OK to flush without running the ABS module. Some people swear this "has" to be done on a JL, but I say horsefeathers because 1) I haven't tried it on a JL yet, and 2) Seems unlikely unless you introduce air into the system (don't).

If you successfully flush, just know that you should probably do a complete flush WITH the ABS module at some point soon. Maybe on the next flush have the dealer or a trusted mechanic with a proper scan/diag tool to do it. It's really not that expensive. Also, compared to letting old fluid rot in calipers, lines, master cylinder, letting it rot in the ABS module is one of the more expensive components to let die over time.

 

[58Willys]

The ABS module has the smallest passages of the entire system, and thus is the most susceptible to damage from contaminated fluid. Get jscan and a dongle for $130 and flush properly, IMO.

 

[BDinTX]

I’ve been eyeballing this scanner for the ABD bleed function also. It’s only $299 at tractor supply so if it doesn’t work as expected I’ll be able to return it easily.

https://www.innova.com/pages/innova-5610-v16?tag=maas_adg_CE14CDCEA4BC7F2C7E088C0D0C7780A3_afap_abs

UPDATE: I reached out to their support to verify it would do an ABS bleed and they said it would NOT on my vehicle. Frustrating since their online tool picker said that it would. I returned it without even opening the box.

 

[Heimkehr]

I usually have the fluid flushed in our Hondas every 4 years or so. As my JLU isn't that old yet, I can only speak to my experience with the former.

Because of the byzantine passageways that an ABS pump adds here, and the importance of purging all air in all places in a vehicle's brake system, I'll have the flush and fill service performed at the dealer. They've specialized equipment for this very purpose, and my experience with each job has been a positive one. This oftentimes includes improved pedal pressure, and always the peace of mind of seeing observably yellow brake fluid replaced with an almost translucent fresh fill. Money well spent, IMO.

 

[nositting]

The ABS module has the smallest passages of the entire system, and thus is the most susceptible to damage from contaminated fluid. Get jscan and a dongle for $130 and flush properly, IMO.

okay, i’m new to this but i like learning and would like to try this.
for clarification, Jscan is an app for your phone, the dongle is what you plug into the obdII port and i’d also need a 12+8 cord? does that go between the dongle and port?
thank you all for any assistance!

 

[Heimkehr]

the dongle is what you plug into the obdII port and i’d also need a 12+8 cord? does that go between the dongle and port?

The 12+8 cable plugs into the security gateway module underneath the driver's side dashboard, above the brake pedal. The free end is used to connect to a wireless OBD II dongle (example.)

I hope Geoff doesn't mind the line jump.

 

[nositting]

I usually have the fluid flushed in our Hondas every 4 years or so. As my JLU isn't that old yet, I can only speak to my experience with the former.

Because of the byzantine passageways that an ABS pump adds here, and the importance of purging all air in all places in a vehicle's brake system, I'll have the flush and fill service performed at the dealer. They've specialized equipment for this very purpose, and my experience with each job has been a positive one. This oftentimes includes improved pedal pressure, and always the peace of mind of seeing observably yellow brake fluid replaced with an almost translucent fresh fill. Money well spent, IMO.

i may go this route depending on how technical this gets.

 

[nositting]

The 12+8 cable plugs into the security gateway module underneath the driver's side dashboard, above the brake pedal. The free end is used to connect to a wireless OBD II dongle (example.)

I hope Geoff doesn't mind the line jump.

oh ok, i get it. thx!

 

[nositting]

soooo
i know this may seem like a dumb question but,
why does this plug into the security gateway (with adapter cable) and not just plug into the obd 2 port? i’ve been trying to learn a little and it looks like products like this often just go into the obd port. unless i’m missing something?

 

[Some Random Guy]

. . .
If you're just flushing though, I wonder if you can open a bleed screw and slowly fill the reservoir so no air is introduced into the system, while a steady stream of fluid just leaks out.

I feel like you’re describing a gravity bleed. Should work. I just didn’t have the hardware to do 4 calipers at once so I went vacuum bleeder.

 

[58Willys]

okay, i’m new to this but i like learning and would like to try this.
for clarification, Jscan is an app for your phone, the dongle is what you plug into the obdII port and i’d also need a 12+8 cord? does that go between the dongle and port?
thank you all for any assistance!

Yes, jscan is diagnostic/service app for your phone; costs about $23. Jscan can read OBD2 codes, reset codes, etc… The dongle is a Bluetooth device that allow your phone/jscan app to communicate with the ECU, about $100 - $130. You will need the 12+8 cable to write info (like bleed ABS) because there is a secure gateway between the OBD port and the ECU.

Go to jscan website and be sure to get one of jscan approved dongles. This may seem complicated, but it’s really pretty easy.

 

[Rhinebeck01]

@nositting

I encourage you to do your homework before buying hardware for use with JSCAN.

Spend the $ and get a decent hardware set-up. You will benefit from a decent set-up and someday when you sell that JL, you will be able to resell this hardware and recoop much of the $ you spent on it.

Anyway, No way today, in 2024, would I ever recommend anyone buying, an old school, clunky, large footprint, outdated, iffy 12+8 cable.

Guys/gals that have a clue these days.... and are buying hardware, go with a dedicated security gateway bypass module. You can buy one from ZAutomotive ... https://www.amazon.com/Z-Automotive...mzn1.fos.18ed3cb5-28d5-4975-8bc7-93deae8f9840

or save a few $ and buy one from ECRI. https://ecri.app/products/ecri-secu...OgRhPDv9fRE2FfWLyBfbmjcqYb0uIWDikTq11iP0NLJZY

Also, do consider buying a Security Gateway Extension Cable..
https://www.amazon.com/Z-Automotive-Z_SGW_EXT/dp/B0B7VR6W1F/ref=sr_1_23?crid=2DZOCFEGQ4FFG&keywords=z+automotive+tazer&qid=1704719575&sprefix=zau,aps,93&sr=8-23

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