Potential brakes binding/handbrake issue?
 

Good morning Scoobynet

Looking for some advice if anyone is in the know, car is a MY03 STI JDM.

Driving home on Thursday I was stop start in traffic. Slowly accelerating in 2nd got to about 3k rpm and come off the gas, the car slowly dropped revs as it should before suddenly slowing rapidly like I was applying the brakes, which of course I wasn't. It did it a few times and then seemed to be ok.

I've been out for a drive or two since to replicate the issue. The first time it did it there was a noticeable squeaking grinding noise coming from what I believe is the rear left corner. I applied the brakes, stopped put the handbrake on and drove away. No more noise. This morning there is a definite squeak from the rear. I applied the brakes slightly, when on no noise but the moment I let off the noise returned, so I applied the handbrake a little to 'clean the shoes' as suggested on here from a previous thread. That seemed to clear the noise. So I'm thinking handbrake.

Further symptoms, the car seems to be a little sluggish over the last few days especially at low revs, and more jerky when changing gear (ie when the clutch is in) when going up through the box, suggesting resistance between gears from the brake binding. No boost issues pulls hard when giving it the beans, it's just at slow speeds or low revs.

The brakes have always been noisy/rough feeling until I've applied them once or twice every time I use the car from it sitting for a day or so. I only use it every other day at best. I believe the brakes are standard and appear to have plenty of life in the discs and loads on the pads.

Does this sound like a handbrake problem? Or potentially a binding caliper? Will adjusting the handbrake potentially sort the issue or will I need to replace parts etc etc?

Finally, last weekend I cleaned out my intercooler. I've put it all back together and everything was fine. I tested the car thoroughly since then (all pipes are done up tight, cooler was 1000000% dry prior to refitting etc etc) and used it plenty before this issue arrived with no problems, but I wanted to mention it in case for some unknown reason it's related.

Complete noob here guys so any advice is very much appreciated.

Binny

Oh one more thing, my drive is a slight slope. When I reverse onto my drive, apply the handbrake and release the foot brake the car rolls forward what must be 3-4 inches. Does this every time and has done since I got it 5 months ago. Another thing that makes me think it's the handbrake (unless that's a trait of Imprezas...)

Id check the rear pads on that side, make sure the caliper is working properly, at this point you can check if the handbrake is dragging at all, if you have done no work on the rear brakes then its uncommon for them to cause a issue, more likely a pad issue,
its when people work on the handbrake shoes there can be issues as the adjuster on the hubs can confuse people.
hth

Thanks for your quick response.

Forgive me as I know nothing, but you say check the pads? I assume you mean pads as in the brake disc pads not the handbrake shoes? How do I check them? They look like they've got plenty of life left, 6-7mm thick. When it come to the mechanical side of thing I'm up for giving it a go myself but it's the brakes we're talking about so want as much info as possible, too important to get it wrong!

Regards the handbrake adjustment, I've read through previous posts and have obtained the Subaru 'how to' sheet. Seems straight forward enough. If that's the issue in the first place of course...

The rolling slightly forward once the handbrake is applied, is that common?

When I have a look tomorrow for potential causes I need to be able to identify if a wheel is sticking or not. If I jack the rear of the car up so that both rear wheels are off the ground will either wheel rotate freely when turned by hand (subject to it not binding)? Will the rear wheels be independent from each other, ie say the left rear is binding will the right rear still turn? Or because of how the diff works if one rear is binding then both will not turn? Sorry for the questions but I don't know how the diff operates and don't want to investigate only to find neither turn because of the 4WD system, not the problem being a binding brake.

Will it be the same for the front wheels if I check them too?

Finally, does the DCCD have to be in a certain position or will leaving it in 'Auto' be ok?

Thanks