ABS Randomly Pumping

[BlackroseZ]

(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]

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]

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

[Starman]

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]

Have you checked your brake fluid levels lately ? GC

[Starman]

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]

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