Opinions on cam belt replacement and brake fluid

AdrianC

HansOndabush said:

The newer synthetic fluids are better than when I started driving too.

Umm, brand new cars still use DOT4 or 5.1. The exact same basic recipe as the old DOT3. Still just as hygroscopic as ever.

Unless you're talking about back in the days of the old red Girling fluid, half a century or more ago?

Citroen's LHM/LDS apart, the only exception to the generic glycols is silicone DOT5(.0), which isn't ethylene glycol based. Both LHM and DOT5(.0) are non-hygroscopic.
Citroen's older LHS (pre-67) was hygroscopic. S-for-synthetic. M-for-mineral, btw.
I'm not aware of any manufacturer using DOT5(.0) silicone as standard. Maybe some of the exotics.

dipsomaniac

Anyone actually change there brake fluid every 2 years? 

Will opening up the system more often let in more moisture?

AdrianC

dipsomaniac said:

Anyone actually change there brake fluid every 2 years?

Anybody following manufacturer schedules.

Will opening up the system more often let in more moisture?

No.
You open it from the bleed nips, you expel fluid (and air), not let it in.
You open it from the reservoir... there's a breather hole in the cap anyway.

HansOndabush

Unless you are a rally driver, you aren't going to boil your brake fluid in everyday driving or an emergency stop.

HansOndabush

AdrianC said:

HansOndabush said:

The newer synthetic fluids are better than when I started driving too.

Umm, brand new cars still use DOT4 or 5.1. The exact same basic recipe as the old DOT3. Still just as hygroscopic as ever.

Unless you're talking about back in the days of the old red Girling fluid, half a century or more ago?

Citroen's LHM/LDS apart, the only exception to the generic glycols is silicone DOT5(.0), which isn't ethylene glycol based. Both LHM and DOT5(.0) are non-hygroscopic.
Citroen's older LHS (pre-67) was hygroscopic. S-for-synthetic. M-for-mineral, btw.
I'm not aware of any manufacturer using DOT5(.0) silicone as standard. Maybe some of the exotics.

DOT 4 is absorbs less moisture than DOT3:

http://www.differencebetween.net/object/auto-object/difference-between-dot-3-and-dot-4-brake-fluids/

"The DOT 4 fluid absorbs less moisture and maintains a higher boiling point than DOT 3 fluid."

DOT 3 in turn was a big improvement on the old Girling and Lockhead fluids that I grew up with (but still never changed those fluids unless doing repairs).

frost500

£70 is such a small amount of money, why is changing the brake fluid ever in doubt. Think about it, it is only half a days wages for most people. What is the problem.

photome

frost500 said:

Water gets every where, it is the ultimate solvent. The brake system is not totally sealed to aerospace standards, if it was cars would cost 10x more. Hence a recommended change interval of 2 years. The moisture gets in a joins, calipers, caps etc. Brake fluid is hard, you can't compress it. Moisture can be compressed, that's why it bubbles. Hope this makes sense. Neglecting a brake fluid change can kill somebody, and it won't be the driver, it will be a kid crossing the road. GET IT DONE Please, regardless of the experience of chancers.

No need to shout.  I wonder if anyone has ever been killed by a driver that didnt change their brake fluid every 2 years

fred246

It's always strikes me it's the sort of trick a magician might do. I fill this system with brake fluid. I empty all the water out. OK the atmosphere is full of water, but where has all the brake fluid that you put in gone to?

molerat

If only garages could check the fluid for water content and other contamination then they wouldn't have to charge every customer £70 every 2 years. Oh, wait a minute, they actually can, I wonder why they don't ?

dipsomaniac

frost500 said:

£70 is such a small amount of money, why is changing the brake fluid ever in doubt. Think about it, it is only half a days wages for most people. What is the problem.

Why are they charging half a day's pay just to change brake fluid?