Changing brake fluid

[Richard n Ann]

I have never replaced brake fluid, always check to make sure level is right.

I didn't realise this was an item that required regular replacement like engine oil.

Will consider getting mine done now.

You can get little moisture test kits. I'd test it first, might be fine

 

[scally]

When did changing brake fluid become part of the service schedule, and why?

When I was earning a living as a mechanic in the 60's 70's and 80's it was just an item that was topped up.

I can understand if you do a lot of very heavy high speed braking, the fluid could boil.

I know people with 20/30 year old performance cars that have never replaced the fluid.

I was wondering that too. I've never change fluid on any of my many vehicles I've owned in my lifetime.

 

[hblewett]

I think spongy brakes due to moisture would be a pretty extreme scenario anyway, we don't drive racing cars or do any Mega Trucking and even if it did become a problem the brakes don't fail, just go spongy.

Not necessarily so - it depends where the line is between spongy and failed. A good few years ago a work colleague went off to Switzerland for a holiday with the family in his car. Descending one of the mountain passes his brakes became almost entirely useless and wouldn't slow him as necessary on the gradient he was on, never mind stop him. He managed to get the car into a lower gear and, being on a main road was able, just to get down to a point where the gradient was such that he was able to bring the car slowly to a halt. It is fair to say that the experience put the fear of *** into him.

When I'm travelling in the mountains, or anywhere else, I want to know that I can use any road that the moho will fit (sometimes only just!) and be safe. The idea of going down a proper zig-zag mountain pass with brakes that aren't 100% does not appeal to me. I get my brake fluid changed at the manufacturere's recommended interval, which for both cars and the moho is 2 years. One of the cars is a 1989, so the 2 year recommended interval is not a new thing. It is in regular use and after 32 years has never had any issues with the ABS or anything else (other than a siezed rear brake caliper because I don't hit the brakes hard enough or often enough - I do now ... an 'emergency' stop every couple of months or so), which I rightly or wrongly attribute to keeping the brake fluid in the condition it is supposed to be.

Another potential issue of not changing the fluid at an adequate frequency is that when you finally come to do it the bleed nippples may be rusted in, with the possibility that if they either can't be moved or get messed up in trying it is necessay to replace them - if that happens all the money you've saved by not having the work done - and more - is gone.

You pays your money (or not) and takes your choice.

 

[wyliecyotee]

Just go down Sutton Bank you’ll soon know if your brakes work ok

 

[L' Hobo]

I would recommend changing brake fluid, I do mine every 5yrs BUT if I was about to embark on a mountainous journey, I would change it before I went.

I acquired my 2007 Murvi about 4yrs ago and have been gradually working through replacing ALL fluids so that I had a baseline to start from.

What surprised me was, when I replaced the BRAKE fluid, I also wanted to do the CLUTCH fluid too as it shares the same reservoir.
On my Fiat Ducato X250, the CLUTCH bleed nipple is a pain to get too as its situated deep down on top of the bell housing and requires the removal of the air filter etc.
I'm glad I did as the CLUTCH fluid was a deep black (which I had never encountered before) because, I was told, it's not part of the Fiat service schedule and, probably, NEVER gets done.

The blackness could only have come from the rubber seals deteriorating and, as the cylinder is INSIDE (what genius thought that one up???) the clutch bell housing, I decided to renew the clutch/pressure plate, cylinders, pipes and driveshaft gearbox seals AND renewed the gearbox oil

Hopefully, should not have any problems in that department for, at least, the next 5yrs.

^{_{Subscribers  do not see these advertisements}}

 

[L' Hobo]

Just go down Sutton Bank you’ll soon know if your brakes work ok

Or if you HAVE to stop going UP!

 

[MikeMex]

I would certainly change it at least every 3 years. 4 main reasons - 1) Brake fluid (the most commonly used fluid) is hydroscopic (absorbs water), 2) it ages and becomes contaminated and therefore the boiling point will decrease, 3) traction control and ABS systems generate heat which help in shortening the fluid life, 4) traction control and ABS systems have very fine clearances and are sensitive to particles in the contaminated fluid.

Water will collect in the lower parts of the system and will corrode some metal parts. If you have drum brakes on the rear (more so in older vehicles) the wheel cylinder wall can corrode to the point where the seal will leak. Same with some brake calipers. changing these parts can be very expensive.

If you have some mechanical knowledge, then you can change your own brake fluid. You’ll need a few simple tools. I change mine on all my vehicles using a pressurised bottle fitted to the top of the master cylinder. There are plenty of ‘good’ YouTube videos to help and guide you. A Haynes manual (if available) for you vehicle is also very useful.

 

[gwyntaxi]

What's everyone's thoughts on changing brake fluid? Just had a reminder for my service and mot and in addition they are suggesting a brake fluid change, is it really necessary? MoHo 8 years old.

Depends really, I’ve got a neighbour who likes his changed on his
Kia car every year which I say is a total waste of money, especially considering that the vehicle is only 3 years old and only driven locally about 2,500 miles a year, I have been told by a mechanic that he cannot change the fluid on my 16 year old Sprinter based Hymer cos apparently it has to be done by the Mercedes main dealer and has to be on their diagnostic machine whilst being done at the main dealers eye-watering labour charges.

 

[mish]

A small addition if I may. 2 years I would think as a maximum. What many forget is that there is a mix of different metals in a brake caliper which is already a potential recipe for corrosion. Adding a hint of moisture ingress through the piston dust shrouds (let alone the hygroscopic element of the fluid) only adds to the possibilities. And remember manufacturer's schedules mostly apply to commercial vehicles that are in constant use . Whereas a moho remains parked for continuous periods usually out in the open and unprotected. Its not worth the risk saving on the cost of a change.

 

[DDJC]

Three year service due next week. Paying the extra £30 for a full brake fluid flush and change.

I've only got one family!

^{_{Subscribers  do not see these advertisements}}

 

[tonyidle]

the cylinder is INSIDE (what genius thought that one up???) the clutch bell housing

It's actually a good idea and does away with several linkages, cable, etc, and the effect on pedal adjustment throughout the life of the clutch. It is changed with the release bearing when the clutch wears out. They don't give much trouble.

 

[G-RMPS]

I had a similar experience many years ago descending a Swiss mountain pass with a Cortina estate tugging a caravan. Brake pedal went just about to the floor. I managed to get the unit into a lay-by. After an hour the brakes were no better. I ended up detaching the van and driving up the pass as quickly as possible to generate airflow. Coming down with just engine braking helped too. I did this twice and the brakes eventually recovered. Lesson learned!

 

[Ivory55]

A small addition if I may. 2 years I would think as a maximum. What many forget is that there is a mix of different metals in a brake caliper which is already a potential recipe for corrosion. Adding a hint of moisture ingress through the piston dust shrouds (let alone the hygroscopic element of the fluid) only adds to the possibilities. And remember manufacturer's schedules mostly apply to commercial vehicles that are in constant use . Whereas a moho remains parked for continuous periods usually out in the open and unprotected. Its not worth the risk saving on the cost of a change.

Out in the open and unprotected, sounds like a normal car around here. I guess it depends if they have a big house and garage, haha

 

[cmcardle75]

Changing it when not necessary is just wasteful IMO. Also why not simmer the fluid in a saucepan to remove the moisture then put through a filter and back in?

Probably because a litre of brake fluid only costs less than a tenner? (And I wouldn't put brake fluid I'd just boiled on the hob back into my vehicle!)

 

[hblewett]

Discussion about miles travelled is, as far as I understand it, noy relevant. It is the absorbtion of water over time which is the main consideration which applies wherever the vehicle is parked and whether it's driven or not.

^{_{Subscribers  do not see these advertisements}}

 

[hblewett]

I have been told by a mechanic that he cannot change the fluid on my 16 year old Sprinter based Hymer cos apparently it has to be done by the Mercedes main dealer and has to be on their diagnostic machine whilst being done at the main dealers eye-watering labour charges.

I have my 11 year old Sprinter based Autosleeper serviced at the MB main dealer; unlike with the cars the MB commercial fixed price servicing rates are pretty competitive. I've just checked my last invoice from January this year and the labour for the brake fluid was £16.70, the fluid itself was £12.95 and VAT £5.93, total £35.58. Not worth scrimping on even for the risks to the vehicle maintenance condition, never mind the consequences of a brake failure, for me.

 

[Googlebot]

If you decide to change it, don’t shear a bleed nipple off the calliper. :-(

 

[L' Hobo]

It's actually a good idea and does away with several linkages, cable, etc, and the effect on pedal adjustment throughout the life of the clutch. It is changed with the release bearing when the clutch wears out. They don't give much trouble.

but when they do, it's an expensive (you have to drop the gearbox) pain in the ar*e, what was wrong with them bolted on to the outside of the bell housing?? (You wouldn't be a garage owner by any chance? )

 

[L' Hobo]

It's actually a good idea and does away with several linkages, cable, etc, and the effect on pedal adjustment throughout the life of the clutch. It is changed with the release bearing when the clutch wears out. They don't give much trouble.

 

[ivorantony]

I agree when they leak and they do it’s a box out to replace even if the clutch it self is still good,
And needless to say you would be an idiot to just fit the thrust/ slave bearing cylinder without doing the complete clutch,
The reason they where design like this is all to do with angles, the old type clutch fork had a pivot point a good distance from the clutch cover assembly, this means when the clutch is depressed only at one point in its travel is the thrust bearing centred on the cover assembly,
This very fact decreases the life of both the thrust bearing and cover assembly so they replaced it with a combined thrust and slave cylinder that is perfectly lined up on the clutch cover assembly at all times regardless whether the clutch is down or up,

^{_{Subscribers  do not see these advertisements}}

 

[tonyidle]

Three year service due next week. Paying the extra £30 for a full brake fluid flush and change.

I've only got one family!

but when they do, it's an expensive (you have to drop the gearbox) pain in the ar*e, what was wrong with them bolted on to the outside of the bell housing?? (You wouldn't be a garage owner by any chance? )

No - I like engineering elegance.

 

[L' Hobo]

I agree when they leak and they do it’s a box out to replace even if the clutch it self is still good,
And needless to say you would be an idiot to just fit the thrust/ slave bearing cylinder without doing the complete clutch,
The reason they where design like this is all to do with angles, the old type clutch fork had a pivot point a good distance from the clutch cover assembly, this means when the clutch is depressed only at one point in its travel is the thrust bearing centred on the cover assembly,
This very fact decreases the life of both the thrust bearing and cover assembly so they replaced it with a combined thrust and slave cylinder that is perfectly lined up on the clutch cover assembly at all times regardless whether the clutch is down or up,

but that's like saying, as there is only one point when your road wheels are aligned, we should change that too and have rear steer on all vehicles?
My last clutch on my 1989 VW California covered 87,000+ miles (and I changed it in 2hrs on the driveway for £135), the geometry can't be that bad.

 

[ivorantony]

I don’t work in engineering design so don’t shoot the messenger
I have worked 50 years in the motor trade and had to replace many clutches, I agree a slave cylinder failure outside the bell housing is easy to repair, But I have had many clutch fork failures and thrust bearing failures on older vehicles that still meant a gearbox out to repair, so old design isn’t necessarily better than new,
But on the other hand
This is why I also run a 30 year old Land Rover that doesn’t have a scrap of electronics (ECUs). The new Defender has 83 ECU It makes you wonder where vehicle design is going,

 

[Yorick]

The brakes are the single most important thing on any vehicle.
Change it every 3 or 4 years and you'll be fine.
And when they change it, the system will be bled, giving better braking performance.

And it's not expensive.

 

[Googlebot]

The brakes are the single most important thing on any vehicle.
Change it every 3 or 4 years and you'll be fine.
And when they change it, the system will be bled, giving better braking performance.

And it's not expensive.

Plus it means the bleed nipple is moved every few years, it is less likely to seize and shear off then. :-(

^{_{Subscribers  do not see these advertisements}}

 

[mikejtaylor21]

I use a brake fluid tester pen and change the fluid when it reads more than 2 percent. you can get these tester pens foor less than £10 off ebay or amazon.