brakes

[les]

I'm keen to run this past you guys for your thoughts, after about 6 days of non use, I used the pick-up today and the first depression of the brake pedal gave a lot of travel, after that, normal from then on. This has been the case after other periods of standing. The fluid is not leaking or in need of any topping up, in fact over a period of 4/5 years it has not needed any topping. I can only think of air.

[scott75]

Hi Les i have the same problem with my brakes i am also unsure of the cause i may have a single cylinder leaking but i too have not needed to top up fluid?????
It may seem a silly question but have you adujsted your shoes?
Hope you get more help all the best Scott

[Kevin]

I can only think of air.

That does sound like the problem Les but does seem unusual that it has not got worse in 4-5 years, the fluid should really be changed a bit more often than this but does depend on the mileage you do, as it absorbes moisture over time which leads to the corroding of the wheel cylinders that our cars are prone to, when was the last time you fully serviced the brake system ?

[les]

Thanks for replies, shoes adjusted with new drums a few months ago. I filled with silicon fluid after the rebuild Kevin, which apparently avoids the tendency to absorb water. A change may not be a bad idea though. My initial concern as you can imagine, is loosing the pedal suddenly, but as I say, if used regularly this problem isn't there.

[Pyoor_Kate]

I presume you don't have a servo....

[les]

No servo, will have to try bleeding the system I think.

[Kevin]

Well I was speaking to someone at our branch meeting last night and they were saying that sometimes Silicon fluid can have some funny effects, and when bleeding it can be useful the night before to put the pedal under pressure as this gives a better bleed action, apparently this is often used on bikes but never having a motor bike I cant comment, but it could be worth wedging the pedal with a piece of wood the night before as it certainly wont do any harm.

[57traveller]

I have silicon fluid in both my cars and I do think the pedal is "softer" but that's not the same as what's happening to Les. I didfind that it was more difficult to remove ALL the air from the system even using Eezibleed. I have read somewhere about leaving a weight on the brake pedal overnight, as Kevin says, then bleeding some more. I suspect air is the problem in Les's case.

[Pyoor_Kate]

Yeah, on a bike it's quite common practice before bleeding the brakes (and if you're not very happy having bled them before doing it again) to tie wrap the brakes on *hard* overnight prior to bleeding.

Certainly lead to much better success on my MZ....

Always wondered why people didn't do it on cars.... apart from the difficulty.

[custommartin]

I can only think of air.

That does sound like the problem Les but does seem unusual that it has not got worse in 4-5 years, the fluid should really be changed a bit more often than this but does depend on the mileage you do, as it absorbes moisture over time which leads to the corroding of the wheel cylinders that our cars are prone to, when was the last time you fully serviced the brake system ?

It's recommended that ordinary brake fluid, like Dot 4, be changed every 2-3 years, whatever the mileage.
Most garages will have a fluid tester if you are unsure how old yours is.

Silicon fluid can be a real pain to bleed properly, but it is worth considering. I always use it now.

There have been cases where silicon fluid has attacked the seals in the system causing leaks, but this was due to the age of the seals rather than anything else.