Brake Booster Motor cycling on and off repeatedly

[WhiteTrash85]

I end up replace the entire brake master cylinder assembly.

Its at the shop right now and looking like that's their recommendation too.

 

[whathejell]

I hav had the exact same issue on my 2004 Land Cruiser. Just finished replacing the entire unit and it’s still clicking on and off. I’ll update if I figure it out.

 

[RkDubs]

I hav had the exact same issue on my 2004 Land Cruiser. Just finished replacing the entire unit and it’s still clicking on and off. I’ll update if I figure it out.

Ever get this resolved? Same issue here now

 

[Cheekblvd]

I hav had the exact same issue on my 2004 Land Cruiser. Just finished replacing the entire unit and it’s still clicking on and off. I’ll update if I figure it out.

Ever figure this out. I have the exact same issue. And I replaced the entire MBC assembly. With the same issue. Intermittent motor running to the cycle of the relay. I will say it does draw fluid from the reservoir. But it's not the constant motor running

 

[TahoeZ]

Motor constantly cycling on and off is typically an issue with the accumulator, but best to replace the entire master cylinder assembly. If it is still constantly cycling after you’ve replaced the entire assembly you most likely have a leak somewhere in the brake system.