Brake pedal feel

[Fez]

Hey guys, I did a track day yesterday and when I came off track after a session, after about 1/2 hour before going back out my brake pedal went straight to the floor and had to be pumped til there was some sort of feel there, out on track the brakes felt okay but seemed like more travel than usual. This happened everytime i went out.

But today i checked the car over and brake fluid was low, maybe used 75-100ml to top it back up, and the brake pedal again was going to the floor, i pumped it up and felt firm, but i could still push the pedal to the floor.
I have Checked for obvious leaks, checked all the bleed nipples and everything looks fine.
Does anyone have Any idea what the issue is?

Honda discs all round
Ds2500 pads up front
Honda pads on rear
Super blue brake fluid (which i put in last week)
Bmcs

Thanks in advance
Huw.

 

[Mark_teg]

If the fluid has ran low you've introduced air into the system. Did you check the level beforehand?

 

[Fez]

Yeah, the level was spot on, and stayed that way all through the day

 

[spooke]

Sounds like it just needs bleeding?

 

[Fez]

It was only done last week, and there were no more air bubbles coming through.

unless my fluid has gone off? It was obviously in a sealed container but it is about a year or so old. Might have had some moisture in it?

 

[spooke]

Possibly, mine did this when I replaced the front pads and had to wind the pistons in, after a few pumps it was fine. I can recommend Motul RBF600 fluid if you do change it

 

[Fez]

Its got to be worth a try.
Yeah thats the stuff i was talking to Hel about, i'll order some, mayswell fit braided hoses the same time lol.

I'll try it and report back.
Thank you

 

[Fez]

I Bled the brakes tonight and they did feel much better, but the car still didn't stop, and they still didn't feel 100%. So i took it for bit of a drive to get petrol, while using the brakes a lot, and they felt like normal again. I'm guess the pads glazed on track possibly?
Either way, they feel awesome now.
Thanks again chaps

 

[spooke]

They may well have, when I first fitted new pads to old discs they glazed badly and were horrible! Glad you got it sorted

 

[Fez]

Strange though, i've done about 10,000 miles on these pads, so surprised they glazed now. I must have not warmed them up correctly on the day.
Learn from my mistakes anyway.. Hopefully haha.

 

[antech]

my pennies worth.
when I bleed brakes on my dc5/ep3 found nipples were prone to air ingression on peddle up, when one throught nipple was done up enough with spanner before peddle up,caused by fine thread on aged castings ,solution thread seal (med strength) on the nipple threads.our little toyota 2003 yaris was easy one to do ,but both my hondas more of a problem. once this done never looked back,and I brake meggar hard ,all my brakes are oem,pads the lot,brembo pads took 100 miles to bed in on new discs at front,but now nice early bite/feel for deeper confidence onto the apex.
if you undo the nipples you will find they are sloppey in casting threads,so easy to induce air by mistake.
Tony

 

[Rom]

Brake fluid is hygroscopic , an opened container will still mean it's old fluid. Once the seals broken, don't trust it.
Treat the fluid you have used, as year old fluid.

A liter of super blue was a tenner last I bought it. I'll just use the whole lot to flush and bleed the system, though I use a pressure bleeder.
It should never need topping up. When the fluid reaches min, the pads will be worn to service life pretty much.


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[Kevin85]

*hygroscopic

 

[Rom]

Ha, that's what I get for typing while working 😔

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[Crazylegs]

On this subject, my pedal feel has gone a bit soft of late.

Got Hawk pads which have been on the car around 5 months possibly longer so they can't be worn already surely?

The fluid was changed at the same time and I have TGM braided lines too. When you put your foot right down they feel fine but up until recently, even after a few pumps they felt quite solid but they've gone a bit squidgy of late.

 

[badeshi]

I gave slightly weird issue... Every now and then the pedal is quite soft and travels further. The braking is still strong and if a press twice the second is usually hard.... I have done tests from service manual and don't think it is cylinder or booster. Started trying to bleed them but couldn't undo rear nipples with mediumforce and was worried I would round them or damage etc... Maybe just have to take to garage...
Bleeding good idea? Any suggestions?