February 18, 2019, 05:19:30 AM

Author Topic: ABS/brake issue  (Read 2429 times)

Offline Gunnytron

Re: ABS/brake issue
« Reply #15 on: April 02, 2018, 06:22:37 PM »
I guess it could be caused by one wheel rotating in the other direction than the other due to the diff?

http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline Cobranut

Re: ABS/brake issue
« Reply #16 on: April 02, 2018, 08:06:11 PM »
I've run my car on the lift, and IIRC, the ABS light does not illuminate unless you hit the brakes while the rear tires are spinning and the fronts are not.
1995 FD, 7.0 Liter stroked LS3, T56, 8.8, Samberg kit.

Offline W.tungsten

Re: ABS/brake issue
« Reply #17 on: April 04, 2018, 05:02:44 PM »
The ABS light might have also illuminated while it was running on jack stands due to only 2 of the 4 wheels spinning. I know ABS systems usually use the speed of all 4 wheels as a input so it may be possible it set a trouble when only two wheels where spinnining making it seem to the abs module that the front two were at full lock.

^ yes this is true. You are setting a plausibility fault. The system doesn't know which pair of sensors to trust. The OP probably letting run for a while on the jack stands, whereas other people did not letting it run as long. Could be like 3-4+ minutes of this would set the fault, so usually a burnout won't trigger this.

Gunnytron, if you unplug your wheel speed sensors or pull the ABS fuse do you ever have this pedal feel issue? If so that would eliminate the ABS system, if no then something is falsely triggering to run ABS (based off your description this is more likely). ABS will malfunction if your wheel speed sensors are wacky as other have mentioned, it would be hard to conclude which sensor is the issue to be honest. Any chance you have really different wheel/tire sizes front to rear?

Offline Gunnytron

Re: ABS/brake issue
« Reply #18 on: April 04, 2018, 05:27:13 PM »
Quote
Gunnytron, if you unplug your wheel speed sensors or pull the ABS fuse do you ever have this pedal feel issue? If so that would eliminate the ABS system, if no then something is falsely triggering to run ABS (based off your description this is more likely). ABS will malfunction if your wheel speed sensors are wacky as other have mentioned, it would be hard to conclude which sensor is the issue to be honest. Any chance you have really different wheel/tire sizes front to rear?

Sound bit of logic there. I will give it a go. As for the wheel, they are all identical.
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline largeorangefont

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Re: ABS/brake issue
« Reply #19 on: April 09, 2018, 01:58:01 PM »
Pull the ABS fuse and drive the car :)
Quote from: cool
Sell it to spacevomit.  He'll finish it.

Offline W.tungsten

Re: ABS/brake issue
« Reply #20 on: April 20, 2018, 12:13:56 AM »
Any resolution?

Offline Gunnytron

Re: ABS/brake issue
« Reply #21 on: April 20, 2018, 02:22:26 AM »
Thanks for asking, but not had another look yet. Been pretty slack. I worked on it last weekend, but ended up just cleaning up and fitting some undertray. :)
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline W.tungsten

Re: ABS/brake issue
« Reply #22 on: April 23, 2018, 06:05:42 PM »
No worries, definitely update us with the end result though!

Offline Gunnytron

Re: ABS/brake issue
« Reply #23 on: May 07, 2018, 01:04:03 PM »
Just had a thought and though I don't think it is my issue, it is related. Should I have a check valce on the hose that runs from the intake manifold to the brake booster?
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline radiomike

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Re: ABS/brake issue
« Reply #24 on: May 07, 2018, 03:16:20 PM »
Just had a thought and though I don't think it is my issue, it is related. Should I have a check valce on the hose that runs from the intake manifold to the brake booster?

No, but a check valve could be useful....

It serves two purposes, firstly it maintains a vacuum in the servo and secondly it protects the diaphragm in the servo from blowbacks in the intake.

Offline Cobranut

Re: ABS/brake issue
« Reply #25 on: May 07, 2018, 03:19:25 PM »
Usually the brake booster fitting has a check valve integrated.
1995 FD, 7.0 Liter stroked LS3, T56, 8.8, Samberg kit.

Offline largeorangefont

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Re: ABS/brake issue
« Reply #26 on: May 07, 2018, 07:11:04 PM »
Did you pull the ABS fuse and drive the car to see if it does the same thing?
Quote from: cool
Sell it to spacevomit.  He'll finish it.

Offline Gunnytron

Re: ABS/brake issue
« Reply #27 on: June 25, 2018, 07:15:41 AM »
Well I finally got off my butt and took the car out today. As suggested, I took the ABS fuse out and the fluttering pedal issue went away.

So, I guess I now I will try wiring in my RLTC properly and see if I can get readings from each wheel sensor.
« Last Edit: June 25, 2018, 07:39:44 AM by Gunnytron »
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline Gunnytron

Re: ABS/brake issue
« Reply #28 on: June 25, 2018, 09:30:06 AM »
The running commentary continues :)

I setup the RLTC on my tablet and managed to communicate with it... sort of. I tried numerous times to get a realtime graph, without success. I did manage to get it going once, but I have no idea how and I couldn't recreate it, which isn't great for testing.

Anyway, from what I could see on the graph the worked, all the speed sensors were giving me a reading of about 80ish, yet the front right was reading 0. That points to a dead sensor or bad wiring of the RLTC loom.

It would be nice if I could get the realtime graph to work again though so I can test a replacement.
« Last Edit: June 25, 2018, 11:25:56 AM by Gunnytron »
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline Gunnytron

Re: ABS/brake issue
« Reply #29 on: July 31, 2018, 02:51:11 PM »
I managed to borrow a multimeter that had millions and hz measurements and here's what the results were:

Before cleaning:

FL
V = 0.09

FR
V = 0.15

Now I swear I had cleaned the front sensors, but they had crusty scale on. Here's the results after a clean:

FL
V = 0.50

FR
V = 0.50

Clean or dirty, the hz were around 60-75 on both wheels.

Not had a chance to test the back ones, but hopefully that was the issue.
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 3.55 Diff, Holley HP EFI, Racelogic TC.