smiff99

can anyone please help.
I fitted new discs pads and braided hoses today, drained the fluid down and then re-filled the system with new, I then bled the system starting with the near side then offside rear then near side and finaly off side front taking care that the resevoir didn't run dry, until there was no more air in the system.
I used aprox a litre and a half of fluid.
The problem is I now don't have a brake pedal unless I pump it, then a few seconds later it's gone again.
Could I have damaged the master cylinder or could it just be air in the same which needs bleading ???
Thanks for any advice.

stockcar

if you've just fitted new hoses i would probs suggest that you have one (or more) slightly loose connections that are leaking/allowing air into the system..............have a friend pump up the pedal, then hold the pressure on while you inspect each junction/banjo bolt to see if you have a leak............

hope this helps,
alyn - asperformance.com

RON

"""""""

JohnD

iTrader: (5)

Sounds like you've still got a lot of air in there! Too late now but you shouldn't have drained the system before re-filling with the new fluid. Air has entered the system and now it's a git to get rid of! Bleed the first wheel and keep topping-up with new fluid until the new fluid flows, this should purge the master cylinder, then do the other wheels until the new fluid flows.
I've tried the one man bleeding kits but always reverted to the two person, long winded method. Don't trust these kits not to draw some air back past the slack threads of the released bleed nipple.
JohnD

RON

Mmmm, didn't read the 'drained down' bit, bound to be loads of air in the pipes around the master cylinder, and also the abs unit, that'll be a bu66er to sort!!

smiff99

Thanks for the advice so far.
I didn't use a one man bleading kit though, it was the wife sat in the car for about 2 hours whilst I tried to get all the air out, obviously to no avail.
As long as I havn't damaged the master cylinder I'll try and bleed the pipes around the it tomorrow and then re do the wheels.

Simon C

I had the same problem when I helped a friend change his fluid and front calipers. WE bled the front but forgot the backs, doh.

We finaly sorted it by: starting at the nearside rear, (furthest from the m/c), then offside rear, then front n/s, then front o/s. After each wheel check and top up the master cylinder. Took us about 1 1/5 hours and 2 laps of the car to get 99% of the air out. Due to re-bleed the system next weekend to make sure and give the brakes a chance to bed in.

HTH
Simon

JohnD

iTrader: (5)

You may eventually resort to getting a garage to pressure bleed the system if all else fails!
JohnD

smiff99

Thanks Jon, maybe thats the next move, however a mechanic had a go at bleeding the system today and he said that I may have damaged the master cylinder!!
I think I'll have a word with Subaru tomorrow to see what they think.

stockcar

find it unlikely to be the master cylinder because of what you have described....................as said above if it pumps up and works for a short period of time its more than likely a loose fitting, etc. causing an air/fluid leak................

alyn - asperformance.com

smiff99

The reason the mechanic thought it may be the master cylinder is because when you pump the pedal, fluid can be seen being pumped up into the resevoir.

RON

I'm sure mine does that as normal.......

JohnD

iTrader: (5)

With a perfectly purged system with undamaged seals there should be no perceptable movement of the fluid in the reservoir.

smiff99

I've just checked another Impreza and Rons right, there is a movement of fluid in the resevoir when the pedal is pumped.
I'm running out of ideas now, next step is to fork out £210 + VAT for a new master cylinder, (unless anyone has a used one for sale) Does anyone know if these differ from year to year or in fact from a UK to an import ?
Thanks,
Jon.

stockcar

no offence but would probs be cheaper to take it to a local garage and get them to diagnose the problem correctly................plenty of s/hand m/cylinders around if you need one!!

alyn - asperformance.com

smiff99

Problem sorted, the front calipers were put back on the wrong side, trouble was that the bleed nipples were then on the bottom not the top, as air rises it made it impossible to get it all out.
So take care anyone removing their calipers for a refurb.
Thanks everone for the advice.

RON

You know I nearly suggested that, but nowhere did you say that you'd actually removed the calipers!!!

Loads of people do it, the air comes out of the top, not the bottom!!!!
Glad it's sorted!

Ron.

stockcar

good news.................as Ron said, hard to suggest something that you presume hasn't happened...........

alyn - asperformance.com

smiff99

Sorry guys, I should have mentioned that in the begining.
I must admit, I thought long and hard before posting my error on here, but then I thought, well, maybe it could prevent someone else making the same mistake, plus it will allow everyone to get a decent nights sleep now that the problems solved
Thanks again everyone.

stockcar

you'd be suprised how often peeps do it..........................suppose if its not something you do on a regular basis its easy to overlook...............

alyn - asperformance.com