Hello.

As some of you know i currently have a problem with my brakes at the moment. I initially susspected a seized brake caliper.

A good check yesterday now leads me to think something else is at fault.

I jacked the car up yesterday at each corner and none of the wheels would turn freely but the fronts being worse than the backs. The car moves but the the binding gets worse the more you push the pedal. Like the fluid is only going one way and not going back once i take my foot off the pedal.

Im no brake expert so am stumped as to what the cause is. Any advice is greatly appreciated. I have a track day booked for Monday and fear i may not make it :(

Kind Regards

Garry

I recon it's that R32 rack of yours. If you like and as a favour I will take it off and fit the standard one back on at no charge.

You may want to check the master cylinder.

Excellent Des. Top bloke. Best to elimimate all possible options i say

It had been mentioned that it could be the master cylinder. Is there anyway of checking this?

Kind Regards

Garry

it does sound like your master cylinder seals have either failed or its full of crap & the piston in the cyl cant return fully,on the rallycar i had with the locked front brakes i loosened the relavent pipe coming out of the master cyl & the brakes freed off straight away so i replaced the master cyl & its been fine ever since,however the rally car didnt have the abs like a octy does,i would be tempted to remove & strip the master cyl & have a look inside,i would replace the master cyl rather than re-seal it etc,when you bleed the brakes & changed the fluid how did you bleed it? did you use a pressure bleed kit or did somebody pump the pedal? if you used the pump the pedal way & pressed it all the way to the floor you could of knackered the seals! what fluid did you put in it? i have known pepole put the wrong fluid in sometimes!

Mikey, thanks for the reply.

It was bleed using a compessor kit to suck the fluid through. I pushed the pedal all the way to the floor in the final tweaking so this could be the problem. The fluid was replaced with DOT5.1 from Halfrauds.

Think i will change the master cylinder then. Only £60.00 so worth a shot :(

Thanks again.

Kind Regards

Garry Curley

I agree with mikey, it sounds like he knows what he's on about.

Mikey, thanks for the reply.

I pushed the pedal all the way to the floor in the final tweaking so this could be the problem.

IIRC pushing the pedal down fully will invert the seals so it sounds as if this may be your problem.

IIRC pushing the pedal down fully will invert the seals so it sounds as if this may be your problem.

That was my thought too. I was allways told never too push the pedal to the floor when bleeding.

Buggar :(

I can design engines for F1, Touring Car, WRC etc... yet cant bleed my own brakes.

Can anyone else see the irony here?

lol

Garry

have you fixed this problem yet garry?:confused:

Not as yet Mikey :(

Our current "best guesses" are that its still the master cylinder. I got a spare one from a local auto factors but it turned out to bethe wrong bloody one :(

Got one on order from Skoda now instead. Bit more money but at least it will be right. It should be with me on Thursday so i can fit it at the weekend and see if that fixes it.

:(

Shall keep you all posted.

Garry

A little update and further advise needed :(

I have now fitted the new brake master cylinder. It seems to have cured the problem in part. Now i have the following symptoms:

Near side front brake - acting free and normal

Off side rear brake - acting free and normal

Off side front brake - Sticking on very strong

Near side rear brake - Sticking on slightly

Does anyone have any further advice on what to check and change?

I dont need the car and use it very little, but as sods law would have it this problem has happened over a period where i have now missed 1 track day and 2 local meets, lol.

This is how my poor car looks at the moment in the JDT workshop :(

Kind Regards

Garry

Have you got pin & slider callipers on (as opposed to opposed piston set up)? If so, could the pins be sticking and maybe need lubricating/calliper replacing?

Have you got pin & slider callipers on (as opposed to opposed piston set up)? If so, could the pins be sticking and maybe need lubricating/calliper replacing?

Thanks for the reply. It does indeed have the stock slider calipers fitted.

We have throughly cleaned and lubricated the sliders on all the calipers but still the problem persists :(

It may be worth noting that if you crack off the bleed nipple on the caliper, a little fluid comes out and the piston slides back in. Like its releving the pressure, but i cant figure out whats causing the pressure build up? When i take my foot off the pedel, surely the preasure in ment to be released.

:(

Garry

Could the hoses be blocked or twisted / constricted? This would stop fluid returning and cause the fluid to leak out when you take the bleed nipple off :confused:

Could the hoses be blocked or twisted / constricted? This would stop fluid returning and cause the fluid to leak out when you take the bleed nipple off :confused:

It certainly sounds like a hydraulic blockage to me.

Would it only stop it one way tho, because it bleeds through beautifully, which tells me there is no blockage.

It all looks okay but is something i could consider i guess?

Garry

You haven't clamped any of the hoses have you?

I believe that on this chassis, the fexible lines are all PTFE lined like a Goodrich hose but without the stainless braiding. If you clamp the hoses they are scrap. Haynes manuals tell you it's OK, but you can't do it as PTFE does not recover like a rubber hose.

I haven't read further than this post, but initial thoughs woudl be to open the bleed screw on a caliper to see if it then freed off. If it did, master cylinder issue. If it didn't, brakes need servicing.

Pressing the pedal to the floor is a big no-no, over the years I have seen more master cylinders wrecked by this than I can think. Reason being there is a 'normal' range and below that the cylinder get muck/corrosion on, if after 10 years you then push the seals down there they can tear/become unseated, generally leading to a sinking pedal.

Also common is pressure bleeding at too high a pressure, this can invert the seals in the master cylinder leading to a 'one way valve' - I went out to a Bedford Rascal a few years ago with this issue. Stripping the master cylinder revealed the seal that was pushed out of it's seat and jamming, it had the symptoms of brakes would go on, but not come off. I fitted a new seal kit, bled it out at a reasonable pressure, all good.

Good luck,

Greg.

Mikey, thanks for the reply.

It was bleed using a compessor kit to suck the fluid through. I pushed the pedal all the way to the floor in the final tweaking so this could be the problem. The fluid was replaced with DOT5.1 from Halfrauds.

Think i will change the master cylinder then. Only £60.00 so worth a shot :(

Thanks again.

Kind Regards

Garry Curley

hi garry,this is turning into a bit of a headache for you now eh?,i can only think of a couple of reasons that may cause this fault,1,you have been unlucky & fitted a faulty master cylinder(i say this as you still have one front & the opposite rear binding)cars have a split braking system so should a brake pipe or caliper fail you still have limited braking available.2,you have a internally collapsed brake flexi(how did you clamp them when you took the calipers off?)3,the piston is siezing on the 0/S/F caliper(i can remember you saying in a earlier post about it the piston not returning then suddenly returing)4,there is a fault in the abs pump(maybe its got muck in it & a valve is not returning hence keeping preasure on & giving you a binding brake.(i dont have vast experience on the abs side of things,maybe somebody else has?)hope you get it fixed soon:thumbup:

I was gonna say it is something to do wi the ABS?

good luck with it tho mate

billy

Just a stray thought but cant you use vag.com to bleed the abs system in the event of a problem. I seem to remember someone had problems after bleeding the brakes due to the abs valves or something and vag.com sorted it.

internally collapsed brake flexi

I've heard of that causing this type of problem.

It is jammed straight away or only after running it up?

If so pop the vacuum pipe off the servo and see if it frees off the brakes.

Just a stray thought but cant you use vag.com to bleed the abs system in the event of a problem. I seem to remember someone had problems after bleeding the brakes due to the abs valves or something and vag.com sorted it.

I've heard of that causing this type of problem.

Right, so the next step is a set of brake lines and to find someone with VAG COM to bleed the ABS system.

It is jammed straight away or only after running it up?

If so pop the vacuum pipe off the servo and see if it frees off the brakes.

Thanks for the reply. They seem to get tighter and tighter the further you drive, even if you dont touch the brakes (it seems). Then if you do touch the brakes, they hold on nice and tight but the peddle feels okay?

I shall have a go at popping the vacuum pipe off and see what happens. Is it best to do this stationary or is it okay to drive and test?

Kind Regards

Garry