Brake fluid testers
 

hi i have just been looking online at these brake fluid testers, they look quite good, but has anyone been able to use these on the clutch master cylinders.


If you have one what do you think of them?

I really would not bother for the clutch fluid. They test the conductivity of the fluid, the more conductive the more moisture they have absorbed, which is important for braking systems - because with hard use, it can boil and you loose your brakes.

Clutch fluid will not get hot, so less of a need for testing.

Thanks Harry

It was rumoured a couple of years ago that brake fluid testing was going to be part of MOT. Hasn't happened yet though. :shrug:

This subject has been aired many times, usually about what DOT fluid to use, (I think it's all DOT 4 now), or whether it's worthwhile to change to Silicone fluid that doesn't absorb water.

From what I've read, the system must be either designed for silicone fluid (the polymer seals I assume) or silicone must be used from new. Basically, swapping from glycol to silicone isn't advised. Either way, I'll not be using DOT5 in mine. I think I read that DOT 5 isn't compatible with ABS.

TC

So how would you know what is in your car especially if its a new car, clutch and brake. As for brake i would use dot 4 and mabe for the clutch as well.

You have no way of knowing, so I make a point of swapping it anyway.

The car as built, had a sealed for life hydraulic clutch system - so no moisture could get in. Unfortunately the hydraulics of the clutch may not have been as robust as it could have been.

As just about all cars have abs what would they use it for if that is the case?:}

T-cut is right, sort of, DOT5 is a poor lubricant compared to DOT4 and ABS pumps don't like this. There is a DOT5(PAG) spec which helps with this.

Thing is I can't really see the point of DOT5. It's main claims to fame are higher boiling point and non-hydroscopic, perfect for performance/racing brakes...BUT...any water it contains tends to pool as it is not absorbed. It is also more compressible than DOT4. Both of those are great reasons NOT to use it in a performance brake system.

For road cars it needs a re-designed system and is non-abs friendly, so not a great choice there either....so what is it for?

The problem is more related to surface tension and the tendency of silicones to foam when pumped. Foaming in the ABS unit is not desirable.

TC