Its at the shop right now and looking like that's their recommendation too.
Brake Booster Motor cycling on and off repeatedly (1 Viewer)
- Thread starter murphthelab
- Start date
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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
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
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.
I'm currently fighting with this issue also. I replaced the accumulator and motor with a new set from City Racer, but not master cylinder. As soon as I turn the key on, it cycles for a few seconds at a time. It does suck down some fluid and build a tiny bit of pressure over time. I assuming the master cylinder needs replaced, but I can't understand why master cylinder failure wouldn't result in the pump running constantly until pressure is achieved, and then maybe cycling constantly as pressure is being bled off constantly. It really seems more like some electronic control is not allowing the the pump to run for more than a few seconds at a time. People have mentioned a pressure switch/sensor but I haven't seen a part number or description of this...
