Coolant in Brake fluid reservoir.

I can't imagine the friend making that mistake. He works on his own cars. The reservoir for the brake fluid is very small compared to a coolant reservoir. And it's located way up by the windshield cowl, very far away from the radiator.

It is more likely he topped off the coolant with green coolant in the reservoir, the one he can't see through clearly. Otherwise he would know it's pink and not green.

I suggest the OP flush his coolant. I would check the brakes but highly doubt that was mixed in.

 

Yes, but the OP stated that there were noises everytime the brakes were applied. Shouldn't happen if only coolant reservoir was involved.

SCH-I535

 

The noise he's hearing could be just the brake accumulator pump noise.

 

Brake accumulator pumps don't make rattling noises though. At least they shouldn't.

SCH-I535

 

Of course it does....that pump noise can most definitely be described as a rattling noise.

If the OP can replicate the sound while the car is not moving, just pressing the brakes, especially when the car just starts up. It's the pump noise.

 

Ok, so you can be the PriusChat "friend" that advises the OP that "most likely" nothing is wrong with their car. Just ignore that rattling sound that was there everytime the brakes were applied, it's just normal sounds. Carry on.

SCH-I535

 

Oh I definitely suggests he checks the brake issue, I'm not saying he shouldn't. I just think he maybe mistaken on what his friend did and where he put the coolant.

I'm just stating from his description of the rattling sound, it sounds like the pump. Have you heard of a rattling brake before that's not a pump?

 

Your brake fluid is fine, it's clean and clear. The worse your friend could have done is mix green coolant with your pink in the coolant reservoir. The rattle noise you are hearing is most likely from the brake accumulator pump.

Confirm with your friend to see if he indeed added coolant to your car. If he did and it's the green kind, go and have your coolant flushed and changed.

 

Your photos of the brake fluid reservoir look pretty good.

However, your car needs major service, regardless. As part of that service, I strongly suggest you have the brake fluid flushed because that particular service doesn't cost very much (should be less than $100) and this will eliminate any lingering doubt that you may have about the integrity of the fluid.

You really do not want to have introduced any foreign liquid, especially one that is water-based, into the brake fluid. That will result in brake components corrosion and in addition will severely impact the performance of the friction braking system because the boiling temperature of the brake fluid will be reduced. You do not want the brake fluid to boil because if the fluid changes to gas at the front disc calipers, you will lose braking effectiveness.

Since the Prius normally relies heavily upon regen braking during normal driving, impairment of the friction braking system may not be immediately obvious to the driver.