ozzy

Driving home last night, doing about 70 on the Motorway. Rush hour, so had to slow down to about 55 when a loud droaning noise started coming from the front of the car and there was some serious vibration through the steering wheel.

Drove a mile or so and pulled into the services. Noise seemed bad around 50-55, but faded away (although vibration didn't) until about 20mph.

Got out and had a look under the car. Turned the wheel lock-to-lock and couldn't see anything obviously wrong with the car.

Got in and headed home (about 12-miles). A mile or so from home (B-roads), I tested the brakes on a couple of corners. Nothing hard, until a little straight into the village. Went to stamp on the brakes and the pedal went to the floor. The brakes worked, just really long. Obviously a little worried, so drove very slowly and the brakes did get me to my house. Pedal was very soft, but brakes still functioned.

Later took the car down the street and after 2 more stops, nothing. If I sit in the car, the brake warning light is on but the pedal goes straight to the floor and I get nothing on them.

The car was serviced exactly 2 weeks ago and they said the pads needed changing soon as they were "starting to break-up". I got some replacement pads at the start of the week and planned on changing them this weekend.

Does this problem sound like just the pads? If so, what surprised me was the way in which the suddenly let go. I've ran pads down to metal before and apart from lots of noise and dust, they still stopped the car.

Other than a fluid leak (I do remember hitting a pot-hole 2 corners before they failed), what else could cause a complete failure?? Rear only seem to work using the handbrake.

Stefan

awd wrx

could be a wheel bearing , if its making a droaning noise , and if its gone the discs will be moving around in the calipers as the hub will be loose and will push the pistons back into the calipers which is why your losing the peddle

You couls loose the brakes for a short while if the pad material comes away from the backplate , but as soon as you pump the peddle it would become hard once the back plate is up against the disc

Or it could be a fluid leak , esspecially if your warning light has come on , is the reservoir still full ?

ozzy

Haven't check yet. Unfortunately when the car was getting serviced they said the bonnet release cable was away. I could still open the bonnet, but now I can't even do that. Since I've not had a chance to fix that, I couldn't check the fluid levels. I didn't spot any fluid leaking around the wheel though.

When I heard the noise, I did think wheel bearing. The brakes should still operate on the rear and on the working front though should it not?

Pumping the pedal seems to bring back an initial bite, but as soon as you press the pedal it goes straight back to the floor.

Would have been a very brown trouser moment if it had happened on the Motorway or if I'd been raging the car around the backroads. Might have been typing this from a Hospital bed

Stefan

awd wrx

no if your wheel bearing is flopping around and it pushes the front pistons back into the calipers , the peddal will hit the floor and you will have no brakes

Jack it up and hold the top and bottom of the wheel and see if there's any movement on them , if you cant see any leaks in the wheels/calipers then it can only really be the bearings esspecially if you hear a droaning noise

ozzy

OK, I'll have a look tonight. Looks like I'll need to get it recovered to them.

Thanks for your help,

Stefan

ozzy

Thinking about the wheel bearing. Would it not take both sides to fail? If the offside had failed and the piston wasn't working, the split braking system should still work on the nearside should it not?

I thought that was the whole point with such a system - that a failure in one part wouldn't render the brakes completely useless (unless it ran out of fluid).

Stefan

awd wrx

if you break a pipe you will loose all the brakes , the only way would would still have brakes is if you have a bias peddal box like they fit on rally cars so you have 2 separate master cylinders , one for the back one for the front ,

ozzy

so, if no pipes broken and plenty of fluid then the brakes should still work with a duff wheel bearing?

Stefan

awd wrx

no they wont , if your wheel bearing has play in it then the hub is loose , as the discs fit on the hub this also means your discs is loose , the caliper will not be loose as its fitted to the hub assembly , the discs will move in the calipers and push the pistons back into the calipers , which means you have to pump the pedal to get them back out before they clamp the discs , if you are driving then as you are bringing the pistons back out the discs moving back and forth with push them back in , if you see what I mean

ozzy

OK, ta.

I'll check the bearing tonight. I'm off to the Czech Republic for a week, so I'll either have it recovered to the Dealer for them to sort next week or wait until I'm back in the UK.

Feel like I've lost an arm without my car

Stefan

ozzy

Dealer price for a wheel bearing is £59.79+VAT. Also needs some new seals at £7 each.

At least it may not break the bank to get it back on the road.

Stefan

ozzy

OK, another theory question. Would a dodgy bearing even affect the brakes when sitting stationary??

If I jump in the car without ignition, then there's virtually no pedal feel. Start car or prime ignition and same thing. Off to try and open the bonnet

New To Scoob

The pedals probably hitting the floor due to the lack of fluid left in the system as your pads have gone, the pistons will almost be maxed out on their travel and you've probably dragged some air into the lines if its that low hence the spongey pedal. This would only have happened if the fluid level was slightly low to start with.

John

ozzy

Been out for another look. With the ignition off or on prime, then there's a little pressure. Pedal's still very long, but as soon as you switch the car on there's absolutely no pressure on the pedal.

I can move the offside outer pad in the caliper, so I'll not know for sure if it's just the pads. I'm beginning to suspect the bearing is faulty, but isn't the direct cause of the brakes failing. It's too cold, dark and wet to do anything tonight plus I want a few beers instead

Stefan

ozzy

After a week away, I finally had a chance to look at the brakes over the weekend. Still plenty of material on all pads, so I'm at a loss to what caused my problem There doesn't appear to be any play in the wheel, so I'm still confused over the wheel bearing too

Changed all pads (front & rear) and had a quick look at the brake fluid. Looks like plenty of air is in the system, which would explain the pedal. What I'm concerned is why it suddenly happend just 10-days after the car was serviced.

If I start the car and push the pedal it goes straight to the floor but I can distinctly hear a 'pssssssst' coming from the front of the car. Doesn't appear to be any leaks on the calipers and I've checked the bleed valves are tight.

Would you expect air noises from a system full of air or does it suggest a leak somewhere ??

Out tonight with the works Xmas part (Monday night I know ), so I won't get a chance to bleed the brakes until tomorrow evening.

Stefan

ozzy

Finally found the problem - hose has rubbed against wheel arch and then split

Some pics:-







Can the hose be replaced without having to buy a complete new set?

Stefan

ozzy

Car was serviced 1.5 weeks before the brakes failed. Shouldn't the Dealer have spotted the brake lines rubbing on the arch?? Don't they inspect the lines during a service?

Guess it could've started rubbing after the service, but I'd be surprised.

Stefan

stockcar

Stefan, they are unfortunately a "crimped" hose set, therefore you can't simply replace the hose as discussed.........................

will have a look in the w/shop tomorrow and see if i have some suitable fittings/hose/etc to sort................

alyn - asperformance.com

ozzy

Thanks Alyn, I appreciate your help.

Stefan

ozzy

Alyn, on another point do you know where I can get replacement bleed valves for the Subaru 4-pot calipers??

I noticed tonight when bleeding the brakes that the N/S looks like the nut has rounded as I had to be very careful not to make it worse.

Stefan

morpheous

iTrader: (9)

Depending where and how soon you need them try companies like:-
Hose Doctor...Pertek...JW Hydraulics...Listers Motorsport...
These companies will make your hoses to pattern and supply all types of fittings whether single or mulptiple

ozzy

Ian from Godspeed e-mailed me to say he could make me a line, so hopefully he'll sort things out for me. Rob G has kindly offered to send me a OE rubber hose to get my car back on the road until I can get a replacement braided hose.

Thanks for those contacts; I'll check them out as it's always good to have plenty of options.

Cheers,
Stefan

ozzy

Car's all sorted now.

HUGE thanks to Cosmic for giving me a replacement braided hose

Stefan

ozzy

Pic of the damage to the hose



Stefan