I thought I’d start a new thread, a continuation of one from yesterday. Hopefully someone will have advice for me. I want to flush my brake fluid and found that the reservoir is extremely dirty. After siphoning off the old fluid,I tried putting additional brake fluid in and then removing it to clean the reservoir, but the dirt is stuck to the sides. I can’t figure out how to remove the reservoir from the master cylinder. Is that possible without removing the whole unit? If not, does anyone know a clever procedure for cleaning the reservoir in place? Please respond as soon as you can, I thought this was going to be a one hour job and now I can’t drive the car. Typical…🤬

 

I've never cleaned a brake reservoir. I started working on cars in the 80's. I've always flushed fluid through and rinse, repeat and go. Jmho

 

I know. I’ve never seen anything like this. It’s almost like an algae is in the fluid. The reservoir does not give a lot of access to the inside because of a restricted plastic piece at the top of the opening. I guess I’ll just take an insert an air hose with a small tube in there and see if I can break the stuff up and siphon it out the best I can The fluid hasn’t been changed since new. Shame on me!

 

I would just drain with a turkey baster or a mighty vac, refill with fresh, and flush the system without trying to clean the reservoir and see if that resolves your issue.

If you are set on cleaning the reservoir then try draining all the fluid and using a steam gun to clean it, then refill with fresh fluid, agitate using a hose to inject air bubbles, drain again and repeat? The *BIG* risk you face from cleaning it in-situ like that is *if* it successfully dislodges whatever gunk is in the reservoir, that gunk will then settle to the bottom of the reservoir and you risk contaminating the master cylinder and the rest of the brake system with it. At that point you have a much bigger problem than a dirty reservoir and sticky float.

Instructions for removing the reservoir are here, page 74. The FSM says to remove the entire master cylinder before separating the reservoir, and then calls out using a special fixture to help clamp the master cylinder in a vice before removing the reservoir.