Gen 1 Prius (2000) – Weak Brakes & High-Pitched Warning Noise – Advice Needed

Hi guys! I bought a 1st gen prius today, for $2000nzd, knowing it had a breaking issue.

just want to get more info on this to try help me do some repairs and further diagnostics.

basically, when the car turns on, there is a constant humming/warning noises, the breaks are very soft and weak, you need to press very hard to get them on.

my understanding is that the brake actuator may be broken? And only one of the two brake systems are working currently, would anyone else have any information to add? The prius is 2000, 1st gen.

apparently the issue occurred after jump starting it.

 

Hi everyone,

I recently bought a 2000 Prius (NHW11) knowing it had brake issues, and I’m trying to diagnose before replacing parts. Symptoms:

• Brakes feel weak and spongy.

• Constant high-pitched humming warning sound when the car is in READY mode. And ABS light on.

• No obvious leaks, but the pump seems to run frequently.

I suspect the brake actuator/ABS pump assembly might be failing, but I’d like to confirm before spending big on parts.

Questions:

1. Does this sound like a failing actuator/accumulator?

2. Is there a way to visually inspect or test the actuator without removing it?

3. Any tips for sourcing a replacement (OEM vs used vs aftermarket)?

4. Will a scanner like Autel AP200 read the relevant ABS codes on Gen 1?

Any advice or experience would be hugely appreciated! Thanks in advance.