Brakes: Brake fluid - test or replace?

[Othen]

Originally Posted by DaveNP

Just to prove how illogical I am on this, for a top up I'd use the bottle in the garage, and my only defence is I can't remember when I last actually needed to do a small top up.

:-)

Alan

[CNGBiFuel]

What are we thinking? Brake fluid is dirt cheap, and so quick to flush thru' anyone would be fool not to. Every two years, three at most. Money on a fluid-tester would be far better spent on fresh fluid.

It's £5-6 at most, and with a pressure-bleeder 20 mins to flush. Compared to the cost, and hassle... and safety considerations of fluid as it degrades to acid, why would you not?

Go mad, buy a gallon for £15.

As for the tester? It'll be 'hook-a-duck stall' grade meter, buy one and be taken for ocean-going fool? What next, a time-share, and a white plastic Disneyland front door?

If it's a proper accurate tool you want, [ie a decent multi-meter], desist asking mindless questions and buy one.

Else, there's this:

https://www.ebay.co.uk/itm/124583213...84.m1555.l2649

[100K+]

My reluctance in changing brake fluid is not the actual task, or the expense. My issue is that during the last 40+yrs of car maintenace, I have NEVER been able to withdraw all the bleed nipples from the cylinders without snapping them. ...and thats a whole new headache.. I've lubricated,tapped,heated, been gentle, but no total success. I put it down to the salt on the roads and ferrous v aluminium components. Yes, my brakes may not be 100% perfect, but I started my driving on all drum brakes and learned to leave gaps between myself and the other vehicles ( not driving so close to the vehicle in front as seems to be the modern way.) So even with years old fluid, my Volvo stops far better than my Mini or Imp ever did, and I've never had a MOT fail for a brake related issue (save one time for my V70 handbrake - which I now fully understand its operation).

Just my 2 pennith

Cheers
Bob

[StanC]

Originally Posted by 100K+

My reluctance in changing brake fluid is not the actual task, or the expense. My issue is that during the last 40+yrs of car maintenace, I have NEVER been able to withdraw all the bleed nipples from the cylinders without snapping them. ...and thats a whole new headache.. I've lubricated,tapped,heated, been gentle, but no total success. I put it down to the salt on the roads and ferrous v aluminium components. Yes, my brakes may not be 100% perfect, but I started my driving on all drum brakes and learned to leave gaps between myself and the other vehicles ( not driving so close to the vehicle in front as seems to be the modern way.) So even with years old fluid, my Volvo stops far better than my Mini or Imp ever did, and I've never had a MOT fail for a brake related issue (save one time for my V70 handbrake - which I now fully understand its operation).

Just my 2 pennith

Cheers
Bob

Regarding the bleed nipple problem, I had the same issue back in the 1970s and found a solution in spraying aerosol underseal on the bleed nipples after I had finished changing the brake fluid. This protected the nipples (and, more importantly, the threads) from road crud and moisture until the next brake fluid change and I always found them easy to unscrew after that. Even now that I get the garage to do the brake fluid change for me, I still spray underseal all round the brake back plate, including the bleed nipples, after I get the car home.

As I understand it, where the brake fluid sits in contact with the wheel cylinder rubber seals it degrades over time and this adversely affects the rubber. Changing the fluid regularly means that 'recent' fluid is always in contact with the rubber seals and this extends the life of the seals, so it's worth changing the fluid every couple of years.

Stan.

[Tannaton]

Originally Posted by 100K+

My reluctance in changing brake fluid is not the actual task, or the expense. My issue is that during the last 40+yrs of car maintenace, I have NEVER been able to withdraw all the bleed nipples from the cylinders without snapping them. ...and thats a whole new headache.. I've lubricated,tapped,heated, been gentle, but no total success. I put it down to the salt on the roads and ferrous v aluminium components. Yes, my brakes may not be 100% perfect, but I started my driving on all drum brakes and learned to leave gaps between myself and the other vehicles ( not driving so close to the vehicle in front as seems to be the modern way.) So even with years old fluid, my Volvo stops far better than my Mini or Imp ever did, and I've never had a MOT fail for a brake related issue (save one time for my V70 handbrake - which I now fully understand its operation).

Just my 2 pennith

Cheers
Bob

That's why I prefer to service my own cars - when doing so I spend 10 mins removing and replacing each nipple and making sure they're free.

[jasons]

Originally Posted by Tannaton

That's why I prefer to service my own cars - when doing so I spend 10 mins removing and replacing each nipple and making sure they're free.

totally agree, I also wouldn't leave brakes to the monkey's at the garage if you are able to do a proper job yourself.

Having recently stripped down 30 year old callipers, you get to see all the crap behind the pistons, you get to measure the break force in psi required for the callipers and soon realise that not changing the fluid regular - and by that I mean at least drawing off a good amount of fluid at each calliper every couple of years - is perhaps not the best long term answer.
Even popping out the fluid res is simple and easy and allows you to clean out all the gunk that lays about there.

Its Ok measuring in the fluid res, but sticky pistons that can boil the fluid often go unnoticed.

Maybe I'm a sucker for being OTT on the brakes, usually each year I do a mini strip down, make sure everything is moving freely, wind back the pistons, lube up sliding pins, draw off some fluid, perhaps my preventative maintenance is the reason why its been nearly 10 years since I last purchased a brake calliper.

[Kev0607]

Originally Posted by morsing

Hi,

Do you replace brake fluid routinely, or rely on a tester to tell you?

It's been a couple of years, but my tester shows up green, so leave or replace?

Thanks

I wouldn’t leave the same brake fluid that’s been in the reservoir, lines & calipers for years without ever changing it, regardless of what the tester said. I don’t mean sucking what’s in the reservoir out either & just topping up with fresh fluid… I mean a full flush/brake bleed job.

Vehicle manufacturer’s seem to frequent offering this as an additional item in the service a lot. I don’t think you need to change it as frequently as they suggest in my opinion. When the fluid is really old, it’ll either go black & it needs flushing immediately (shouldn’t be let go this far though), or it’ll be a dark brown colour & you definitely want to think about getting it flushed.

As for a time schedule, flush/bleed every 3/4 years I reckon (regardless of colour). If the fluid is brown before that period lapses, then flush/bleed it early. Don’t leave it longer than 4 years though without ever flushing/changing it though & never let it get to the stage where its pitch black in the reservoir!

[ITSv40]

Originally Posted by jasons

Maybe I'm a sucker for being OTT on the brakes, usually each year I do a mini strip down, make sure everything is moving freely, wind back the pistons, lube up sliding pins, draw off some fluid, perhaps my preventative maintenance is the reason why its been nearly 10 years since I last purchased a brake calliper.

That has been my routine on all my cars for the last 15 years. Part of the annual check/service prior to mot. All brakes perfectly balanced during the test and pull up straight on the road.