Firm Brake Pedal
 

Bled all the brakes today, a little air came out.

I'm assuming as the brake pedal is firmer it knocked a bit of air out the system but what i want to know is, please:

On the first 3 brakes i bled, rear nearside, rear farside and front nearside i had the brake fluid filler cap off, i then tightened it back on as my dad popped out, when he got home we did the last brake, front farside, but i forgot to loosen the brake fluid cap, it remained tightened while we did the last brake.

Would/could this cause a problem?

Also if you forget to put your filler cap back on and you use the brakes does this cause a problem?

I did it once before by mistake but it seemed fine.
I also earlier started the car and gave the brakes a pump while the filler cap was off. There were a few bumbles that appeared in the reservoir but it hasn't effected the pedal firmness?

And how do all your pedals feel, mine is very firm now, when i press it it has very little travel and then kicks in, not spongy at all. Is that good?

Thanks

The firmer and less travel, the better.

Aye, less travel, more confidence.

As for the implications of not having the cap on I would have only worried if fluid had overflowed once pressurising the system again. The pro’s will know for sure what could have happened.

I had a think about it and surely if there was pressure then it would have been difficult to bleed or not bleed at all, but that didn't happen.
When i released the filler cap, that would have resored pressure, a lot like when you screw the lid of a jar and there is a little pop, but there was no pop as there wasn't enough pressure lol.

I'm mostly curious about what driving without the filler cap on could do?! And what the bubbles i saw where when i pumped the brake with the filler cap off.

Thanks

driving ithout the cap on, could spill fluid all over your engine bay and over time im sure brake fluid absorbs water from the air so would eventually cause a poor pedal and corrosion to some inner parts of the braking statem

wouldnt have a massive immediate effect tho unless spilled onto turbo, caught fire ect... lol

I don't think the filler cap is "that" air tight anyway. Otherwise when the brake pads wear down; the extra fluid needed wouldn't be able to drain from the reservoir (bit like an air lock).

Air bubbles maybe a bit of air trapped in the master cylinder. You should give the pedal a few brisk pumps with all the bleed nipples shut off every now and again whilst halfway through bleeding each caliper to help shift any air stuck in the system.


TBH you won't know what the score is without driving the car for a bit; If the pedal starts going soft and spongy in the next few months then that would be indicative of a problem with air getting in the system somewhere. If it remains as it is currently, no problem :cool:

Thanks