Bigfoot928

What is the best way to clean a brake fluid reservoir? You might say just buy a new one... its only plastic. Check the prices and then you may want to figure out how to clean it as well..

Shark2626

Motive Brake Bleeders recommends cleaning their systems with denatured alcohol. That and a soft toothbrush should do the trick on the inside.

But if yours is old and dry, meaning dark yellow or brown plastic, 928 International might have a good used white one.

SeanR

Wurth Brake cleaner, shake it around. Repeat until clean.

Bigfoot928

The one I'm trying to clean is from 928 intl. I may have to spring for a new one, as this one is pretty orange....at least I think it's orange.

kawi825

I recently used brake cleaner first, then soaked it overnight in simple green/water. Worked great. Dried best I could them let it sit for day or two then blew out with compressor. Attachment 1313184

Mrmerlin

I have typed this up a few times, it works great and takes about 20 mins to complete
PB the tank grommets , remove the tank,
spray with brake cleaner .
NOTE use the good stuff not the stuff in the green can,
I use CRC brakleen on the red can.

Use a tooth brush on the seams and areas around the cap and the lettering.
rinse the tank off.
Fill about a 10 second spray into the tank and cover the holes and shake vigorously . then drain.
Repeat this step a few times.

Then get some simple green and spray the tank,
use a toothbrush on the seams and the letters .

Then add about 2 oz into the tank and shake vigorously while tipping the tank so the cleaner is well distributed, and with the holes plugged.
Rinse with very hot water.

Repeat this a few times till your happy with the new looking tank.
final rinse it with hot water till no bubbles come out.

Get denatured or rubbing alcohol and add about 2 oz to the tank ,
shake vigorously for about 30 seconds while you tip the tank up and down to distribute the alcohol
drain it out and repeat.
final drain the tank.,
Shake thew tank till no more drops come out,

Then get a hairdrier and blow warm air into the inlet till you no longer smell alcohol.
your tank is now ready to install.

NOTE I use DC111 on the tank testing rubber boot,
this will restore its pliability and add a layer of water dispersion..

Also I use it on the inlets /metal area of the new MC and the grommets and tank inlet barbs,
and the MC seal to the booster.

NOTE when the MC is installed and the car gets wet,
water runs down the tank and around the tank inlet grommets,
if you dont have any way to prevent moisture from touching the bare metal it will soon start to corrode under the grommets.
This leads to leaking grommets,
The DC 111 will prevent this from happening and prolong the external life of the MC indefinitely
NOTE I suggest to use ATE brake fluid

The Forgotten On

^^ Fun fact. Wurth brake clean is the same in both green or red cans if you live in California, one just costs more.

Petza914

What's the real difference between the green can and red can brake cleaners? From this exchange I gather the red works better and is worse for the environment - that sum it up?

Zirconocene

@Petza914 : Spot on. I don't know about CA, but the red can where I live has chlorinated solvents included. They work some magic for breaking up crud but are not so environmentally friendly.

Cheers

dr bob

If you have access to an ultrasonic cleaner, your options expand by a lot. Put the reservoir in a ziplock bag with Simple Green, and put coarse sand inside the reservoir. Run it in the ultrasonic, and the sand will scrub the plastic for you. Rinse it in clear water when you are done, and be sure to get all the sand out. Flush with rubbing alcohol to clear any remaining moisture, then air dry completely. Store in a clean ziplock until ready to use, then follow Stan's excellent protocol with the DC-111 silicone grease on the master cylinder ports and the grommets when you install it.

Brake-clean products vary, and for the most part are unnecessary for this duty. Simple Green does a fine job getting the brake fluid out, and that's really all you are asking of any solvent in this exercise. Rubbing alcohol is pretty harmless to human skin, and the vapor pressure is enough to keep it from concentrating enough to be a hazard to eyes-nose-mouth-lungs vapor contact. Meanwhile... brake-clean products tend to be more volatile, higher vapor concentrations, where skin contact leads to nervous system damage. The vapor condenses on eye tissues, and also respiratory surfaces where the damage continues. Yes, it's a handy solvent-flush for lots of things besides brakes. Yes, you really need to heed the warnings on the can and follow the use directions. The chlorinated stuff is verboten in California for the greater risk of nerve damage, and it's more carcinogenic than the plain versions. Not saying the plain versions are significantly less, just that they haven't been researched as much. Do you need them to clean the reservoir? No. Would they do a good job displacing water left inside? Sure, but... Isopropyl (rubbing) alcohol will take care of that too, almost as fast, and you can always just leave the reservoir out for an hour on a not-cold day and let mother-nature's sun take care of that drying-out step for you. Save the brake-clean for removing the last assembly fingerprints from brake pads and rotors during final assembly. For everything else there are much safer products.

Mrmerlin

I would caution about putting any kind of sand or rocks inside the tank as there are small screens that could either be damaged or capture the particles and later release them into your new master cylinder

my suggestion on tank cleaning protocol has been updated and perfected over many years of restoring these machines

And if followed should result in a perfectly clean tank

That’s ready to be installed and put into service

Zirconocene

I will second, third, and fourth the ultrasonic cleaning, even without the sand or abrasive. I have access to some of these baths at work and put them to use cleaning filthy alternator cases. It's a bit of magic, how effective it is, and how quickly it works. It sure beats a toothbrush and soap. IPA is also a wonderful solvent to get things dry. Not only does it remove water via being infinitely miscible, it forms a nice azeotrope and lowers the energy (heat, in this case) needed to get water to evaporate.

Before I thought to go with using the tools available to me at work, I took Dr. Bob's advice, mixed with some of Stan's recommendations, and went after my brake fluid reservoir with Simple Green and a lot of shaking to dislodge small amounts of what looked like a fine black powder that had accumulated over the years. Took a bit longer, and was probably not as efficient as with ultrasound, but the reservoir was much closer to the OEM color once I was done. I rinsed everything out with denatured alcohol once I was done, as that's what I had easily to hand, and let things dry over a couple of days.

Cheers

Ad0911

The simple way is to dump it in a bucket of water with approx 2-3% caustic soda and leave it for a week or so. It will be like new after that. Just rinse afterwards

dr bob

You can do this on a less-aggressive scale with the TSP you use to clean painted walls prior to repainting. TSP is readily available and just slightly less dangerous to handle than caustic soda, even the diluted stuff.

Lots of options!

Ad0911

Perhaps,, I don't know this stuff. It'll have a different name here in the Netherlands. For me the caustic soda is the active agent in cleaner for food equipment. We use this all the time in the distillery so easy access. The car is near the distillery.

Btw, this stuff also does wonders for the coolant tank. Just keep it immerged for a week.