brake help!

[gate78]

hey guys, just thought id post a problem im having, with luck somebody may solve my problem.

Just put some new front and back brake pads (had rear disk conversion ages ago) and although they were a slag to fit, due to rust and mud, and a seized calliper on the back i got them on, and they all seem to be grabbing with no obvious leaks. The brakes were working ok before the new pads (excluding the seized calliper) but now the brake pedal needs pumping before the brakes work. i have bled a few litres of brake fluid through each calliper in the correct order, and no more air is coming out.

I have also now noticed a kind of hissing noise, like pumping a bicycle pump when the brake pedal is pressed, this comes from around the brake fluid reservoir. there are no leaks alond the whole system that i can see, and as they worked before surely it is unlikely something just broke?!? Im still just hoping it is air in the system, but if so where could it be and how do i get it out?

any help, suggestions or ideas much appreciated! what have i done wrong? any thing i can do to diagnose a faulty component? Im very reluctant to put it into a garage unless i exhaust all my options.

cheers guys in advance!

[Mart]

have you checked the seal ring on the reservoir cap? might be perished so your not holding the pressure, just a thought

[gate78]

just had a look but the seal looks good as new. with the engine running if i press the brake pedal 2-3 times then i get resistance and the pedal feels normal, and the brakes work. as soon as i release the pedal, and press again, the resistance is gone and the pedal drops to the floor (the brakes do still work like this, but id never stop fast enough in an emergency).

thanks

keep the ideas coming guys
 :D

[P.R.Howler]

Its good practice to change fluid once a year too, fluid gets too much moisture in it and becomes less reliable, sounds like you have air in the system m8, check bleed nipples are fully screwed in,ie, no crap behind them.
When you push the pistons back into caliper you can sometimes nick the rubber seal, if you get too much crap behind the dust cover this will break down the seal too.

[generation-x]

hi m8 wot rear calipers are u using?
if sj front ones did you move the rears so the bleed nipples are at the same position as the fronts else they wont bleed right

let us no

simon

[gate78]

WOW cheers Simon, that sounds like it might be the problem. The rear callipers are from the front axle of a 410, and they are at about 10 o'clock as you look at them on the hub (the front ones are on the top as i assume these were on the last vehicle). seems to make sense that there might be air ABOVE the bleeb nipples on one or more of the rear callipers. cant beleive i didnt think of that, and ill try and check it out soon.

thats why i love this forum, you can learn loads.


thanks mate, ill post here when i find if it has helped or not.


ps. would that account for the hissing sound from the front do you know? hope so!

[generation-x]

no probs mate its a common thing with the rear disc conversion
as for hissing do you no were its comin from?

simon

[gate78]

the sound seems to be coming from around the master cylinder/brake fluid reservoir area, when you depress the brake pedal. sounds like a bicycle pump. im hoping its just another symptom of what i hope is the AIR problem. im sure they didnt make that sound before, but ill post after i get a chance to re bleed the callipers.

cheers again mate.

[Evilgoat]

Duff servo?

Might just be normal servo noise too and thus a red herring. Rabbit's brakes were like this for some time until I had bled them about 3 times.

[gate78]

cheers for all the help, after moving the rear callipers and bleeding them in the correct position the problem is a lot better. still not right though, im thinking the master cylinder might be fecked. However one of the rear callipers is grabbing, but not releasing properly. Gunna take it to a mechanic mate of mine who did the SPOA for me, hopefully he can diagnose for me.

Unfortunately now its not starting, so although ive just replaced the solenoid on the starter, looks like something else has broken, lol

oh well never give up, its a learning experience...

[gate78]

starting now! after ages spent checking fuses and connections, turns out my brother had put the wires to the starter the wrong way round! [Edited], at least it was easy to fix once discovered. just my brakes again, until i find something else! lol

[Mart]

its always something obvious you tend to overlook for thinking its something else normally a simple fix as well

[generation-x]

gate m8
clamp off the rear brakes with some mole grips on the main flexy line if you can then try taking it round the block see if any better

simon

[baz2236]

Did you ever resolve you brake problem i have a similar issue with my brakes but i do not have rear disk conversion ...

[gate78]

hey mate, it did help when i bled the brakes at the right angle. but turned out my master cylinder was on its way out, and probably is what is wrong with yours baz. i ended up having to buy a brand new part for about £150, but you could try and find a second hand one, piece of p$$s to fit. hope that helps mate