Car pulls under braking. Uneven wear at the front? Pictures attached

[Yiannis197]

​Hi guys,

My car has developed an issue and it really caught me by surprise yesterday night. When I tried to brake heavily the car pulled massively to the left, so much that I nearly lost the rear as I wasn't even expecting that!

Now the basics,

The capilers are spot on, no seized pistons etc
Inner roads are newish given that they came with the brand new steering rack
My brake lines are fine (Hel, fitted them 2 months ago alongside discs and pads)
Tracking is fine (the car drives straight)

I haven't checked tyre pressures but i don't think they are out, I did check them 2 weeks ago.

So what's next? I've read somewhere that it might be worn wishbone bushings? Car passed MOT in July (wouldn't they have picked it up?) and it was absolutely fine on the trip (September) right after fitting brand new discs and pads.

I do remember a similar thread started from A2ON but i can't find it!

Thanks in advance.

 

[Kelv]

It wasn't a horrid rut in the road caused by lorries atall was it?

 

[Yiannis197]

No Kelv, I did test it again with the same results (expecting it this time lol). This is what I originally thought tbh but it seemed to be a wishful thinking

 

[Kelv]

I was clutching at straws in hope it was something simple to allocate to the blame.

 

[Yiannis197]

haha I wished mate!

Any chance the right caliper is under performing? Would something like that be possible? Anything wrong with the brake balance maybe?

 

[Kelv]

the only way you could tell would be to check that all 4 pistons are free and moving with ease, and that the fluid flow is reaching the caliper with no restrictions.

 

[deadmau5]

I had this happen once. Check your brake pads are all in one piece. One of my rear pads had come away from the backing causing the car to pull to one side under braking.

 

[sideways danny]

Almost certainly one caliper is sticking or not bled properly.

 

[Yiannis197]

Thanks guys, I'd have to investigate.

The thing is that my mechanic stripped and cleaned the brakes all around after I came back from my trip and that was 3 weeks ago (I didn't test the brakes since then tbh). We sanded down the pads to retrieve a fresh surface and get rid of the cooked areas (till i buy new ones anyway), cleaned the calipers etc. No corrosion, the pins came out effortlessly and no indication of sticking rear calipers. However we didn't change the fluid (which fluid boiled at some point therefore needs changing).

I'll have to have a look tomorrow in case I notice anything obvious...

 

[deadmau5]

Check the brake lines are all in correctly, it's possible to cross thread them and think they're fully in.

 

[Yiannis197]

Cheers Ross, I had a look for anything obvious, the lines seem fine.

However, I have a rusty line on my both rear discs which suggests that the pads do not contact the discs properly, why is this happening? Here is a pic


Untitled by YiannisR27, on Flickr

Untitled by YiannisR27, on Flickr




On top of that, after inspecting my front discs I noticed that the left one has been unevenly worn! It is barely noticeable but it is there and if you run your finger across the rotor you can feel it. A couple of pics


Untitled by YiannisR27, on Flickr

Untitled by YiannisR27, on Flickr



I'm talking about the middle surface of the rotor. So does that suggest that the caliper doesn't do the job properly? I'm positive that i haven't got a sticking piston (as I said we stripped and cleaned 3 weeks ago) so my only thoughts is only if the caliper does not bite as strong as the other one? Still, do you reckon I'd have to change the fluid? It def needs changing....

Thanks

EDIT. My mechanic also told me that at some point I'd have to change the guide pins for the pads (rear), would that affect the braking by any means?

 

[Womble]

Instead of guessing would it be be easier to pop into your MOT place or friendly garage and get it on the brake tester. That will instantly give you information as to where the problem is on the car, you can then start to investigate the possible cause, and tell us all what it was

 

[Yiannis197]

Cheers Womble, the car passed MOT in July with no issues but I'll have to have it checked on the tester. Loads of stuff can go wrong in 3 months I suppose..

 

[madlynx]

Any updates on this issue mate? I'm having the exact same problem (car pulls to the left under hard braking). How did you manage to solve your problem?
Thanks in advance and sorry for the necropost)

 

[choppen]

mine done this and it was down to air in the brake lines