ABS Randomly Pumping - ZR-1 Net Registry Forums

BlackroseZ · 08-15-2023

(1992 zr1) I know about the abs self check on startup but this is different. At random points whether it's a few min after startup or an hour into a trip the pump just randomly comes on. I get the abs light and all. Worried it might start to damage the pump as it happens several times while driving. I recently had to take out the front hubs so I suspected it had something to do with removing the 2 front abs sensors but I reconnected them and it did nothing. Help would be appreciated

secondchance · 08-17-2023

Could it be a poor electrical connection in the power to the pump is making the system think the car was just started and going through system priming and a self check?
I would try reseating all electrical connectors to the ABS system.

Matt B · 08-17-2023

Tires maybe? What rear tire size are you running on?
My 335 Michelins tend to trigger the ABS every now and then.

Starman · 01-22-2024

This was originally attributed to low quality power relays. There are likely posts in the stickies that cover it. The suggestion was to first replace the primary ABS power relay and then a secondary one if the first did not correct. I replaced the primary on my 91, which did not help. Still haven?t gotten back around to the next step.

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GOLDCYLON · 01-23-2024

Have you checked your brake fluid levels lately ? GC

Starman · 01-23-2024

Full and recently flushed with the brake upgrades. Will have to drive it more to see if somehow cured, but mine have never been low.

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AlbanyBrian · 01-23-2024

Have you bleed the system, in particular the prime line between the MC and the ABS unit behind the drivers seat? I was getting the ABS light under hard braking in my 93 after I purchased the car. When I bleed the ABS prime line I got 5 to 6 small bubbles out of that line. After that I no longer get the ABS light when braking hard. Good luck solving your issue.
Brian

08-15-2023	#1
BlackroseZ Join Date: Jun 2023 Location: Austin, Texas Posts: 10	ABS Randomly Pumping (1992 zr1) I know about the abs self check on startup but this is different. At random points whether it's a few min after startup or an hour into a trip the pump just randomly comes on. I get the abs light and all. Worried it might start to damage the pump as it happens several times while driving. I recently had to take out the front hubs so I suspected it had something to do with removing the 2 front abs sensors but I reconnected them and it did nothing. Help would be appreciated

08-17-2023	#2
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: ABS Randomly Pumping Could it be a poor electrical connection in the power to the pump is making the system think the car was just started and going through system priming and a self check? I would try reseating all electrical connectors to the ABS system.

08-17-2023	#3
Matt B Join Date: Jan 2021 Location: Beautiful Bavaria Posts: 523	Re: ABS Randomly Pumping Tires maybe? What rear tire size are you running on? My 335 Michelins tend to trigger the ABS every now and then. __________________ ZR-1 #638/1991

01-22-2024	#4
Starman Join Date: Sep 2008 Location: Speedway, IN Posts: 133	Re: ABS Randomly Pumping This was originally attributed to low quality power relays. There are likely posts in the stickies that cover it. The suggestion was to first replace the primary ABS power relay and then a secondary one if the first did not correct. I replaced the primary on my 91, which did not help. Still haven?t gotten back around to the next step. Sent from my iPhone using ZR-1 Net Registry

01-23-2024	#5
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: ABS Randomly Pumping Have you checked your brake fluid levels lately ? GC __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

01-23-2024	#6
Starman Join Date: Sep 2008 Location: Speedway, IN Posts: 133	Re: ABS Randomly Pumping Full and recently flushed with the brake upgrades. Will have to drive it more to see if somehow cured, but mine have never been low. Sent from my iPhone using ZR-1 Net Registry

01-23-2024	#7
AlbanyBrian Join Date: Feb 2023 Location: Albany, Oregon Posts: 36	Re: ABS Randomly Pumping Have you bleed the system, in particular the prime line between the MC and the ABS unit behind the drivers seat? I was getting the ABS light under hard braking in my 93 after I purchased the car. When I bleed the ABS prime line I got 5 to 6 small bubbles out of that line. After that I no longer get the ABS light when braking hard. Good luck solving your issue. Brian