t4and greys

Hi all am hoping someone can shed some light on the problem I have with her indoors car
Just getting it ready for the mot and having a lot of problems with getting a firm brake pedal as is very soft

Car is a 02 bugeye wagon and has 4 pots ,new brake pads all round
Now have tried bleeding it using lots of different methods inc furthest wheel away then diagonal opposite etc
And also nearest first then opposite etc to no avail
Used the normal hand method and also the easy bleed aswell with same result spongy pedal ,brakes do grab but very low down on the pedal

Have also tried just gravity bleeding them ,also swapped the master cylinder aswell with no change in feel

Think servo or booster is working correctly as with ignition off and foot on the pedal starting car up pedal drops a little which I'm told means the servo is good

Brake pistons are free and have no visible leaks or splits in any of the brake pipes either

Just need some fresh ideas now as its only thing stopping me putting a mot on the car as just rebuilt and refitted the engine which has been much easier than these pesky brakes argh

Is there a one way valve in the servo vacuum pipe that could possibly be leaking not sure if subaru s have them or not
And before anyone asks nipples are at the top lmao

Turbotits

iTrader: (2)

Have you done any miles on the pads?They do need a couple of heat cycles to firm up.
Does the brake pedal pump up? If it does its a sure sign of air in the system. If they always stay the same id suggest the pads need bedding in.

You dont say youve removed the calipers. Incase you have. Are they on the right side? Bleed nipple at top of caliper.

t4and greys

I bought the car with a blown engine and only found out there was an issue once I'd fitted new engine and ran the car
Have given it a few miles to bed in but still no joy with them
But with ignition off pedal does get firmer once they are pumped ????

Oh and as I said in first post nipple is at the top as was first thing I checked lol

madscoob

iTrader: (3)

get someone to pump the brake pedal while you check to see if the rubber pipes are expanding,

Turbotits

iTrader: (2)

sorry must have missed that lol. Yep going firmer when switched off is normal.

What pads have you put in?

t4and greys

Just put some new mintex pads not special tbh but they are new
Old pads that were fitted didn't even look that bad either to be honest , just wanted to rule out the pads
When it is pumped by someone I can see the pistons pushing the pads under pressure with each pump too ??

Could it be a faulty abs unit or something else

Turbotits

iTrader: (2)

Very unusual

only other thing i can think of is that your getting pad knock off. Usually caused by play in a wheel bearing.

Although if your getting the problem without moving the car thats unlikely

t4and greys

Gettin on my nerves now this bloody car rebuilt the engine in a couple of weeks ,fitted it in 3 hours
But it's taken a week so far on these bloody brakes and it Doing my head in hahahah

Turbotits

iTrader: (2)

2 pots or single pot sliders on the rear?

Clutching at straws could be a siezed slider

tayscooby

iTrader: (3)

Clamp off all flexi hoses at calipers and see if pedal solid. If it is then remove clamps one by one or front first then rear until you find pedal goes soft. If its still soft after clamping all hoses then problem lies before calipers ect

tayscooby

iTrader: (3)

Oh and dont attempt to drive car with them clamped lol

sssssteeeee

u get spongey brakes if the fluid has boiled, or been boiled at some point.

t4and greys

Yeah cheers for the suggestions guys appreciate it
Has new dot 4 in from when I swapped master cylinder over and barely driven it to boil it
Will try clamping the hoses as just wondering if its possible they can collapse on the inside ???

Turbotits

iTrader: (2)

Yep ive had them on other makes colapse. But the other way round. Brakes were binding on after braking as fluid couldnt get back up the pipe

Baz82

When bleeding have you got the ignition on(lights on ,engine off) ?

I have had serious peddle feel problems with a few different Abs equipped cars when the ignition is not on.

Also you could have an issue with the master cylinder. Also what condition are the discs in?

t4and greys

Disks aren't in bad nick and as for bleeding I always do it with the ignition on anyway , but just to make sure have bled it whilst running , whilst totally off and also with just ignition on

See that's what's doing my head in have methodically gone over everything as a process of elimination and still no idea what's wrong lol

And master cylinder already been swapped for a good known working one so isn't that

t4and greys

Will try clamping them off like posted earlier on and remove clamps one by one until i find the problem other thn that and trying new fleck pipes I'm stuck

Just fed up of throwing money at it when I'm not curing the problem lol

Baz82

Next step would be bench bleeding the master cylinder

merlin24

iTrader: (1)

Or you wedge the brake pedal down with a piece of wood against the seat frame and leave it overnight - quite often lets any trapped air back up into the master cylinder.
You may need to pull the fuse for the brake lights if they stop on with the pedal wedged down.

I use a similar method on the motorcycles I service as they can be an **** to bleed.

Mick

t4and greys

Forgive my ignorance but how do you " bench bleed the cylinder " please
At least it something I haven't tried I suppose

t4and greys

Sounds like a good idea merlin is it best to leave cap slightly undone ?

Will go try that in a moment see if it makes any difference in the morning ?

t4and greys

Right just googled bench bleeding thanks for the idea , will bench bleed my original master cylinder tomorrow on the bench
See how I get on

merlin24

iTrader: (1)

I normally leave the cap on.
It's something easy to try as you can leave it overnight to see if it helps cure the problem.

Mick

t4and greys

simple idea but overlooked by myself tut tut

hoping its just something silly but in reality its a right royal PITA