Was out in my 98 classic tonight, and took it for a blast, and when applying the brakes, OMG.... The brake pedal went completely hard, for a split second, and this happened quite a few times, high speed and going slow, like the pedal wouldn't even move, then u try Again and it was ok,

Please say someone has a solution or a good idea what this is,

 

This maybe..

ABS delete kit.

https://www.scoobynet.com/car-parts-...lete-kits.html

 

Airlock,seized caliper piston?
Or like Dubzy says,the ABS system is poor on the Impreza,down right dangerous sometimes tbh. ABS Delete kit is the way to go.

 

When this happen, does the pedal feel the same as if when its being pressed with the engine off after a few pumps?

If so it sounds more like loss of vacuum; Check vacuum pipe to booster (servo) for splits, kinks or collapsing (when engine is idling) and one-way valve. Be very suspicious if silicone hoses have been fitted (brightly coloured- original hoses were black and were hard plastic tube) as the valve often gets thrown away; That will give a intermittent hard pedal...as when the turbo kicks in the engine has no vacuum to give brake assistance; Vacuum is normally stored in the servo, but it won't if there is a leak or faulty valve, and full vaccum is only restored during engine overrun and idle. At low engine speeds or idle, it can take a few seconds to for assistance to be fully restored.

ABS issues would be obvious by the noise the pump makes and vibration from the pedal; ABS doesn't give a hard pedal, just one that moves but does eff all or gives good initial braking then a reduction of braking when the ABS pump kicks in, and is usually a symptom of mismatched/cold/glazed pads or defective calipers or air/degraded fluid (not to forget mismatching/nasty tyres - any ABS systems can't work well if the tyres have no grip, the old 3 channel systems were no exception ).

 

Let me know how you get on my widetrack braking feels dead hard as I come off the motorway aswell but saying that I've done bout30miles in 6months of ownership?

 

Yes Ali-b, that's exactly how I would describe it, it's just rock solid, for a second or 2,

I can't see anything wrong with the pipes when I was under my bonnet today, anyway will see if that front Godspeed brake kit makes a difference and fresh oil, when it comes, also got Yokohama parade spec 2, tyres aswell, will keep you all updated,

 

Might it be an idea to get it bled at a garage, using subaru approved method

 

How are the yoko prada spec2 like on the impreza? I have just bought some and fitting I the next phew weeks.

Cheers