Bleeding Brakes & Fitting Pads - Please Help!

[Juz 0]

i bought some red dot discs and mintex pads to go on my 1.6 gti as an upgrade from the standard parts.

 

i've got the discs on but the pads won't fit as they are unworn. i guess that this means the brake system needs bleeding to fit them in?

 

i've bought a gunson eezibleed as i've never bled car brakes before and this made it look a lot easier and help prevent against getting old fluid/air trapped in the system. however... with this being pressurised i'm assuming it won't allow any give in the caliper to squeeze the new pads in?

 

could somebody please explain how i can do this? should the pads go in whilst bleeding with the gunson or do i have to bleed manually to release the pressure in the system first?

 

thanks...

[hengti 2]

sounds as though to need to push the pistons back into the caliper

 

have you got a Haynes manual?

[TEKNOPUG 3]

You need to wind the pistons in to allow room for the pads to fit. The eezi-bleeds can be good if you can get it to seal properly over there MC Reservoir - otherwise you'll just spray brake fluid everywhere. The 2 man method is probably best.

[Juz 0]

yep i have a haynes, it's very old and missing bits though

 

how do i push the piston back into the caliper? can this be done without bleeding the fluid?

 

the eezibleed came with a selection of reservoir cap sizes for all the different brake types, including girling which i think mine are? so if/when i do bleed using it i think [hope] it should work without spraying the fluid all over the show

[TEKNOPUG 3]

yep i have a haynes, it's very old and missing bits though

 

how do i push the piston back into the caliper? can this be done without bleeding the fluid?

 

the eezibleed came with a selection of reservoir cap sizes for all the different brake types, including girling which i think mine are? so if/when i do bleed using it i think [hope] it should work without spraying the fluid all over the show

 

 

You need to wind them back in - there should be some grooves on the pistons with which you can use a screwdriver to wind the pistons in. With regards to the brake bleeding - it doesn't matter what brakes you have as you just need to attach the plastic pipe to the nipples; it the fluid reservoir on top of the master cylinder which you need to seal.

[hengti 2]

you don't normally need to bleed the brakes at all if you're changing the discs/pads - only if you've disconnected any of the pipes or suspect that there may be air in the system.

 

had forgotten that 1.6 front calipers are the same as 1.9 rears - as above, you can just wind them in using a suitable screwdriver placed across the cutouts on the edge of the piston. no need to bleed to do this, but you might need to drain some of the fluid from the reservoir (use a syringe if you've got one - or get one from a chemists) as the fluid will rise as you wind the pistons back in.

 

if you still want to bleed the brakes, Easibleeds are excellent imo - you just need to be sure that you've got a good seal over the reservoir and on the fluid bottle. connect it all up to a spare tyre without fluid in the bottle first and listen really carefully for leaks - should be ok.

 

no need to bleed unless you've still got a spongey pedal though - i wouldn't bother unless you absolutely have to as it's easy to snap the bleed nipples and then you'll likely be needing new calipers.

 

after you've changed the discs/pads, the brakes will likely feel rubbish for a while - they need to bed in so don't panic thinking you've a problem.

 

hth

 

ed. typing too slow!

Edited March 17, 2007 by hengti

[Juz 0]

there is a large grove all the way around the outside of the piston, but no groves in the actual face end of it with which to wind it... i'll take a picture in a second...

[Juz 0]

right here's a photo of the piston with the rubber outer seal removed... you can see the groove ring around the outside but on the face (slightly obscured by the copper grease!) it's completely flat...

 

 

i'd already started to wind the bleed nipple out a little thinking that it might release some of the pressure and let the piston back in, so after i get the pads in i'm going to have a go at bleeding the system anyway. the brake pedal was a little spongey before so they were probably ready for doing.

[hengti 2]

thinking again (!) the pistons at the front aren't going to have grooves in them as that's part of the handbrake mechanism for the rear calipers only

 

just press the pistons in with a G clamp if you've got one or carefully lever them in using a screwdriver and a block of wood

[Juz 0]

ahhhh thanks, the g-clamp with a couple of pieces of wood worked a treat... got the new pads in now dead easy

 

i have however discovered that one of the bleeding nipple screws was in crossed, since taking it out i now can't get it to tighten up properly when putting it back in. the screw itself looks fine so i think it must be the thread in the caliper that's knackered. s*it! guess i will have to replace that caliper now!? if i source a similar mileage second hand one for the same side will i be ok? or would it be better to replace both calipers at the same time?

[Richie-Van-GTi 70 2 Cars]

you be fine replacing just one caliper.

[Juz 0]

thanks for all the advice chaps! and thanks to dodsworth_gti for selling me his calipers

 

i've been a busy bunny today, got the calipers all cleaned up and fitted, bled the brake system replacing it with fresh fluid, then fixed an annoying electrical short which was causing my left front indicator to intermittently stop working, and then affixed the peugeotsport colour stripes stickers on the front grille

 

i took the car out for a drive after doing the brakes and they are so much keener than the old ones. but, if i pump the brakes when stationary i can hear a sort of "pssshh" noise as though it's coming from the pedal???? even though the brakes feel so much better, could this mean i still have air in the system? i realised after this that whilst i was bleeding the brakes i had left the handbrake on (front was on axle stands still so i didn't want it to fall off) - could doing this have caused air to stay in? i couldn't find any mention of what position the handbrake should be in either the haynes or the gunson eezibleed instructions.

 

here's a quick pic of the stickers too... i fitted them with the grille off the car in what i thought looked like the best position at the time, but after putting the grille back on i think they'd look better further over away more off-centre! :[ fortunately i have another set so will see how i feel about them in a couple of days and maybe re-do them

 

(excuse the dirt, she needs a good wash!)...

[hengti 2]

good to hear you've sorted it

 

bleeding with the handbrake on shouldn't have caused any problems

 

the hissing you're hearing is likely the servo. it should exhaust itself after half a dozen pedal presses (with engine off). there's more detail in the 'road test' section of the service schedule in Haynes

Edited March 21, 2007 by hengti