ScoobyNet.com - Subaru Enthusiast Forum

ScoobyNet.com - Subaru Enthusiast Forum (https://www.scoobynet.com/)
-   Wheels, Tyres & Brakes (https://www.scoobynet.com/wheels-tyres-and-brakes-13/)
-   -   Brakes locking on (https://www.scoobynet.com/wheels-tyres-and-brakes-13/945321-brakes-locking-on.html)

JonMc 10 August 2012 09:10 PM


Originally Posted by prodriverules (Post 10745127)
Good news Jon,I did try and get them out when I refurbed them mate but they wouldn't budge,most brembo's/k-sports and AP's are all the same with that shim holding screw:brickwall

Pedal pressure seemed fine on the way in to work, whilst it did change a little no where near as much as previously, but the drivers side caliper is still hotter than the passenger side. I'll jack the car up Sunday afternoon and see if it is still binding when I spin the wheel and if it is time to enlist some more experienced help, I'm happy with the basics but deeper diagnosis is getting beyond me:freak3:

I would be thinking a blockage in the lines but the pistons all pushed back fine and pumped up again once I'd fitted the pads.

Would air bubbles cause a problem and would bleeding be a worthwhile next step:wonder:

prodriverules 10 August 2012 09:16 PM

Certainly worth a go mate,we have a VW polo in at the moment with a very very similar problem of O/S/F brake binding and we have almost eliminated everything except the ABS pump so you may need to be looking towards that having now eliminated the calipers and pads.

JonMc 10 August 2012 09:22 PM


Originally Posted by prodriverules (Post 10745532)
Certainly worth a go mate,we have a VW polo in at the moment with a very very similar problem of O/S/F brake binding and we have almost eliminated everything except the ABS pump so you may need to be looking towards that having now eliminated the calipers and pads.

I will need to find someone local who can re-run the brake lines and tee together the front and rear pipes through an adjustable proportioning valve - removing the pump will also make more space for the induction kit:thumb:

prodriverules 10 August 2012 09:24 PM


Originally Posted by JonMc (Post 10745541)
I will need to find someone local who can re-run the brake lines and tee together the front and rear pipes through an adjustable proportioning valve - removing the pump will also make more space for the induction kit:thumb:

That is my way of thinking as well in mine Jon,that and the fact it just looks plain ugly sat there:freak3:

JonMc 10 August 2012 09:41 PM


Originally Posted by prodriverules (Post 10745545)
That is my way of thinking as well in mine Jon,that and the fact it just looks plain ugly sat there:freak3:

Have you found anywhere that sells the proportioning valve for decent money - seen a few wilwood ones in the states for about £40 but they seem to be double that in the UK. Also any ideas whether or not any 2-way valve will do or is there any spec that I need to be looking for:wonder:

prodriverules 10 August 2012 09:43 PM

Tbho I may just try and have a word with one of the ebay traders and have on of there's sent but with gift marked on it to save the tax etc??

JonMc 10 August 2012 10:01 PM

I can't find the 'how-to' I was looking at a couple of months back but my thought is something like this one:wonder:

http://www.merlinmotorsport.co.uk/p3...a4a3d4244b333d

I know you have to tee the fronts and rears together rather than have the four independant lines you have from the ABS pump, but iirc there's four lines in/out of the standard pump and only three into the one above:freak3:

JonMc 10 August 2012 10:05 PM

Found it:luxhello:

http://www.jamessimpson.co.uk/impreza-abs-removal

prodriverules 10 August 2012 10:09 PM

Bingo!!
I think I may as well just rip mine out as the engine bay is going to it's bare bones anyway!

Don Clark 10 August 2012 10:58 PM

The brake pdf posted above also contains the non abs circuits

JonMc 11 August 2012 08:43 PM


Originally Posted by Don Clark (Post 10745724)
The brake pdf posted above also contains the non abs circuits

I'll read through and print the pages. I thought it was cracked as when I got home this morning the caliper temps were even across the calipers but coming in to work tonight the brakes over heated to the degree that the binding was causing a rumbling until they cooled down again. As it is only one caliper I am convinced it is either the ABS or the lines that are not allowing the pistons to release - I would suspect the propotioning valve if it was a pair of caliper as they onle have 2 channels coming out.

Time to break into the piggy-bank:eek:

JDM_Stig 11 August 2012 09:01 PM

anyone local you could swap callipers with to test them to be 100%

JonMc 11 August 2012 09:13 PM


Originally Posted by JDM_Stig (Post 10746531)
anyone local you could swap callipers with to test them to be 100%

Calipers appear fine - pistons all move freely and the new pads are not sticking when the brakes are cold. Also the calipers were refurbed 6-months ago.

prodriverules 11 August 2012 09:24 PM

I would defo be looking at the ABS Jon,it isn't the calipers and you have now eliminated the pads so it must be something in the system ie ABS pump/master cylinder.

Turbotits 11 August 2012 09:37 PM

Its worth changing the flexi hose as well. Ive had one colapse (not on a scooby) caused similar issues. The pressure from the pedal allowed fluid down to the caliper to apply the brakes, but wouldnt allow the fluid out so the brakes stayed slightly on. Then ofcourse that side got hot

prodriverules 11 August 2012 09:39 PM


Originally Posted by Turbotits (Post 10746592)
Its worth changing the flexi hose as well. Ive had one colapse (not on a scooby) caused similar issues. The pressure from the pedal allowed fluid down to the caliper to apply the brakes, but wouldnt allow the fluid out so the brakes stayed slightly on. Then ofcourse that side got hot

Very good point,I should have thought of that myself.

JonMc 11 August 2012 09:41 PM


Originally Posted by prodriverules (Post 10746594)
Very good point,I should have thought of that myself.

The hoses are braided so they should not have collapsed and they appeared to be okay on a visual inspection:wonder:

prodriverules 11 August 2012 09:44 PM


Originally Posted by JonMc (Post 10746598)
The hoses are braided so they should not have collapsed and they appeared to be okay on a visual inspection:wonder:

Another very good point lol,it just keeps leading back to the ABS pump or master cylinder tbho mate.
Plus you can do your ABS delete and detail the job to which I can copy :lol1:

JonMc 11 August 2012 10:52 PM


Originally Posted by prodriverules (Post 10746604)
Another very good point lol,it just keeps leading back to the ABS pump or master cylinder tbho mate.
Plus you can do your ABS delete and detail the job to which I can copy :lol1:

I've PM'd one of the local members to help out with the delete - it's getting beyond my amatuer abilities and I don't have pipe-bending or flaring stuff. Found the Wilwood valve and some t-pieces on ebay for about £60 all in.

The way I read it is you tee the fronts and rears together and use the valve to set the front/rear balance in the absence of the ABS pump - seems quite simple. Off to print the noddy guide and read it properly, good old night shifts:D

JonMc 11 August 2012 10:54 PM


Originally Posted by prodriverules (Post 10746604)
Another very good point lol,it just keeps leading back to the ABS pump or master cylinder tbho mate.
Plus you can do your ABS delete and detail the job to which I can copy :lol1:

More to the ABS though as I would expect the fault to be more than one line if it was the master cylinder. It only seems to split into 4-channels at the ABS pump:wonder:

prodriverules 11 August 2012 10:57 PM


Originally Posted by JonMc (Post 10746706)
I've PM'd one of the local members to help out with the delete - it's getting beyond my amatuer abilities and I don't have pipe-bending or flaring stuff. Found the Wilwood valve and some t-pieces on ebay for about £60 all in.

The way I read it is you tee the fronts and rears together and use the valve to set the front/rear balance in the absence of the ABS pump - seems quite simple. Off to print the noddy guide and read it properly, good old night shifts:D

Have you got a link for the wilwood valve and t-piece's mate and yes I would be more looking towards the ABS than master cylinder for the problem:)
I am set on deleting mine now:thumb:

JonMc 11 August 2012 11:04 PM


Originally Posted by prodriverules (Post 10746716)
Have you got a link for the wilwood valve and t-piece's mate and yes I would be more looking towards the ABS than master cylinder for the problem:)
I am set on deleting mine now:thumb:

I'll stick them up tomorrow when I get up after my night shift - I can't get on ebay in work:(

prodriverules 11 August 2012 11:06 PM


Originally Posted by JonMc (Post 10746728)
I'll stick them up tomorrow when I get up after my night shift - I can't get on ebay in work:(

No worries Jon thanks :thumb:

JonMc 12 August 2012 03:37 PM


Originally Posted by prodriverules (Post 10746716)
Have you got a link for the wilwood valve and t-piece's mate and yes I would be more looking towards the ABS than master cylinder for the problem:)
I am set on deleting mine now:thumb:

Here's the bits I've found - I'm making the assumption that my measurements are good and I have 10mm connections and 3/16" pipework so you need 2 of these...

http://www.ebay.co.uk/itm/3603921223...#ht_1083wt_906

and one of these...

http://www.ebay.co.uk/itm/WILWOOD-26...ht_1480wt_1111

I read up on it last night and the job is simple:

Tee the 2 front lines together and connect to one output from the master cylinder.

Tee the 2 rear lines together and connect to the bias valve. Connect the bias valve to the second output from the master cylinder.

Adjust bias valve so the back brakes lock up first for serious tail out action:D

prodriverules 12 August 2012 04:33 PM


Originally Posted by JonMc (Post 10747391)
Here's the bits I've found - I'm making the assumption that my measurements are good and I have 10mm connections and 3/16" pipework so you need 2 of these...

http://www.ebay.co.uk/itm/3603921223...#ht_1083wt_906

and one of these...

http://www.ebay.co.uk/itm/WILWOOD-26...ht_1480wt_1111

I read up on it last night and the job is simple:

Tee the 2 front lines together and connect to one output from the master cylinder.

Tee the 2 rear lines together and connect to the bias valve. Connect the bias valve to the second output from the master cylinder.

Adjust bias valve so the back brakes lock up first for serious tail out action:D

:notworthy:thumb:
Good man Jon,that's another job on my list which is as long as my leg:freak3::D

JonMc 12 August 2012 04:49 PM

Only one of the unions on my ABS pump is seized so I should have enough unions and pipe to recycle it - and no, the seized one is not the O/S/F either, that would have been too simple:wonder:

JonMc 14 August 2012 06:14 PM

Postman arrived today so I just need the garage to let me know when is good to run along so we can bend and flare all the pipes to suit:norty:

Need to do a steady couple more runs to work and back at the current rate though:eek:

I can't think of anything else as a block in the pipe would not allow the pistons to push out as well as retract, all the pistons are free and move when the pedal is pumped, and the only part that is channel specific is the ABS pump - hopefully I'll be happy again soon...

http://img.photobucket.com/albums/v5...6/IMG_0519.jpg

Also had these turn up from CRN today ready to replace my rather sorry looking rear OE discs:D

http://img.photobucket.com/albums/v5...6/IMG_0520.jpg

I can then get my Brembo HP sport rear pads fitted and the brakes should be all done:thumb:

prodriverules 14 August 2012 06:59 PM

Not hanging about there Jon,good man:thumb:

JonMc 14 August 2012 07:02 PM

Can't afford to mate - even been toying with buying my own brake flaring kit and pipe bender but I still need to get on the ramps so I can drop all four wheels off and bleed the brakes:D

prodriverules 14 August 2012 07:07 PM

I can't wait to ditch my ABS and have a much cleaner inner wing area on that side!
It will be good to see what your feelings are on the brakes after removal as well!


All times are GMT +1. The time now is 03:58 AM.


© 2024 MH Sub I, LLC dba Internet Brands