Hello.

Changed my discs and pads yesterday. Opened the brake fluid reservoir to find the fluid as shown in the image .

My concern is I have had a reputable independent garage change the fluid two months ago when the car went in for timing belt and water pump replacement.

The fluid appears to be overly dark and cloudy.

I have contacted the garage who have said the image shows clear fluid around the edge and the middle looks like a reflection of some sort.

What would your reaction be if this was on your car .

Many thanks for your time .

Doesn't look right.

I think the yellow strainer is removeable, have you tried lifting it out to see what is in it?

Otherwise, can you syringe out some of the discoloured fluid into a clear container?

It just looks like junk, ie small bits of "system rubber" that is sitting on the floor of the strainer, I've tried to get these strainers out of there and found it a bit tricky - so left it in place.

"Gulping" the excess fluid out using a new "turkey baster" might work to remove some of that junk and fluid.

If my garage left the strainer full of that cr*p, I'd be looking for a new garage PDQ!

Lift the strainer out and clean it, post a photo of the actual fluid. If it's not perfectly yellow/clear then ask them to replace again.

Mine is 10 years old and fluid only replaced once (I know...but I test it and it's fine)it's clear....certainly doesn't look like that!

5 hours ago, Adam_F said:

My concern is I have had a reputable independent garage change the fluid two months ago

Did it look good straight after they changed the fluid?

Maybe they did change the fluid in the reservoir but didn't flush the lines

2 hours ago, robs12 said:

Mine is 10 years old and fluid only replaced once (I know...but I test it and it's fine)it's clear....certainly doesn't look like that!

How on earth do you test it? Glycol based brake fluid is hygrosopic (absorbs moisture from the air) thus reducing its boiling point. In extreme circumstances, this can lead to brake failure when the fluid boils as a result of heat transfer.

The other effect of moisture uptake is corrosion inside the steel components of which there are several.

11 hours ago, BlueWagon said:

Did it look good straight after they changed the fluid?

Maybe they did change the fluid in the reservoir but didn't flush the lines

To be honest I didn't check the fluid when I collected the car , I fully understand that to make assumption's is not the best . But the description on their web site offer the service as "Brake fluid service / brake fluid replacement " £69.00

11 hours ago, SwallownAmazon said:

How on earth do you test it? Glycol based brake fluid is hygrosopic (absorbs moisture from the air) thus reducing its boiling point. In extreme circumstances, this can lead to brake failure when the fluid boils as a result of heat transfer.

The other effect of moisture uptake is corrosion inside the steel components of which there are several.

The fluid is tested for moisture content using a conductivity tester.

It can be argued that this test may not be complete unless test fluid is taken from the wheel cylinders, rather than at the master cylinder.

Edited 29 September, 202529 Sep by Warrior193
expanded

3 hours ago, Warrior193 said:

The fluid is tested for moisture content using a conductivity tester.

One could also argue that seeing as condensation is generally fresh, demineralised water, it won't be conductive, so won't show up in a conductivity test.

You need ions, so from salt or corrosion products to see the moisture as a conductivity reading, and without knowing the TDS and the composition of those ions, it's a pretty random number.

Personally I'd just change the brake fluid from time to time.

17 hours ago, SwallownAmazon said:

How on earth do you test it? Glycol based brake fluid is hygrosopic (absorbs moisture from the air) thus reducing its boiling point. In extreme circumstances, this can lead to brake failure when the fluid boils as a result of heat transfer.

The other effect of moisture uptake is corrosion inside the steel components of which there are several.

Search for Brake Fluid Tester...there are many options. They work well from my experience.

2 hours ago, BlueWagon said:

One could also argue that seeing as condensation is generally fresh, demineralised water, it won't be conductive, so won't show up in a conductivity test.

You need ions, so from salt or corrosion products to see the moisture as a conductivity reading, and without knowing the TDS and the composition of those ions, it's a pretty random number.

Personally I'd just change the brake fluid from time to time.

H2O in any form has a very high affinity to minerals and I believe it would be practically impossible for water to remain sufficiently ion free for long in a natural environment.

17 hours ago, Warrior193 said:

n a natural environment.

Brake system hardly a natural environment....

18 hours ago, robs12 said:

Search for Brake Fluid Tester...there are many options.

Plenty of options of snake oil on the net too...I'd be wary

Natural environment reference was for non-laboratory conditions.