Brakes over winter

[markm]

Since having the brake calipers refurbished on my car, the brakes have never really felt the same, not as firm anyhow. Changed out the master cylinder to try and solve the problem, but still after a winter period the pedal seems to disappear, so needs bleeding again.

Do any of you suffer the same, seem to have to beheld your brakes yearly. Getting quite expensive in brake fluid now

[hot66]

yes i've had this a couple of times over the years .. last year in particular if you remember . Re-bled through new fluid and all is good again

[markm]

What about after your winter Kay up this year, have you had to redo them again?

[hot66]

Not driven it for ages but last time I sat in the car in the garage and made brum brum noises they felt normal

[markm]

I reckon I’ve got a dodgy pipe in the front offside caliper. When I got it back from refurb, it leaked. So instead of driving back to Chester I just tightened it a bit more and leak stopped

[hot66]

Have you bled them since ?

[markm]

I have, several times.

[911hillclimber]

I've had my 911 since 1988.

It has been sat in garage and outside even over every winter since and have never had these problems.

In that time I've re-sealed the caliper pistons with the correct ATE kits and have endured very hard bleeding sessions to get a hard pedal, but once achieved, all is well and consistent.
The calipers were last done about 10 years ago, the hard lines, aeroquip flex hoses were installed in 1993 and never been changed since, a new master installed at the same time.
Bleeding can take an hour....and about 3 litres.

I use simple DOT4 fluid from a motorfactor (nothing fancy at all) and a very patient wife who does the pedal actions.

A real pita job I avoid if I can.

Flushed the system last year and no pedal issues at all before or after.

Good luck, i know how frustrating it can be.

[Ian Comerford]

I don’t know if this is of use. I have read theories that suggest it’s possible for seals in newly rebuilt callipers to 'pull' the pistons back in after pressure release, creating the feel of a long pedal. Eventually, with use, it goes away. This has been discussed a few times over on Impact Bumpers.

[markm]

Interesting Ian, I’ll drive ut a bit then before I bleed them, see us it makes a difference, should be fun though as you have to have 2 bites of the pedal to get anything meaningful with regards to a brake pedal working

[Gary71]

Sounds like a part issue. In theory you should be able to leave it for ages and not have a problem.
Possibly one of the calipers has an air leak, very subtle one, but a leak nevertheless.

Maybe between the calipers halves or something like that

[911hillclimber]

You only need a bubble in there, somewhere.
This is why I think I have to beleed'bleed'bleed and more to get the last one.
I tap each caliper while the wife is doing the up n down bit(!)

I suspect the M calipers at the back.

[911hillclimber]

You only need a bubble in there, somewhere.
This is why I think I have to beleed'bleed'bleed and more to get the last one.
I tap each caliper while the wife is doing the up n down bit(!)

I suspect the M calipers at the back.

Once done to death the hard pedal that results is permanent, never softens.

[sladey]

Sounds like a part issue. In theory you should be able to leave it for ages and not have a problem.
Possibly one of the calipers has an air leak, very subtle one, but a leak nevertheless.

Maybe between the calipers halves or something like that

I don’t buy that Gary - if the system is pressurised any leak would be of fluid and leave telltale signs

For bleeding I use a pressurised system from sealey - think it was about £60 and is really excellent and easy to use

[Ian Comerford]

Interesting Ian, I’ll drive ut a bit then before I bleed them, see us it makes a difference, should be fun though as you have to have 2 bites of the pedal to get anything meaningful with regards to a brake pedal working

Is it worth trying something like repeatedly pressing the brake pedal for several minutes, or as long as your leg will take it? If the theory is sound and a few believe it to be your brakes will settle/bed in and behave normally. It’s free exercise and you only lose a bit of time……