Single knock when braking

[Gaverick]

Ever since I bought my car (30k miles ago) I've had this knock. It happens when I brake, usually just as I'm about to come to a stop, one single knock from the front drivers side. It feels like something is loaded up as I pull away and then released when I brake, for example once the knock has happened, it won't happen again unless I accelerate before I brake.

Things I've changed on the car which I thought might be causing it are;

Track Rod Ends
Ball Joints
Powerflex ARB Bushes (inner and outer)
Powerflex Dogbone
KTEC Engine mounts
New front and rear dampers
Eibach Sportlnes

My suspicions now lye with either;

Top mounts
Driveshaft has a slight hole in the inner boot
Ball joint hole in hub could be ovaled

Has anybody experienced this before and have you managed to sort it out?

It's not a major problem, car still drives fine but it's very annoying.

 

[Faxo]

I'd say bottom arm

My mums car (CMax) had the exact same symptoms, knock when accelerating, then a knock when braking, but never in between. It was the rear bush moving one way, then the other

 

[welshname]

Hmmm. Are you sure you've replaced the balljoints with the correct item? I had this problem, put on the supplied balljoint only to realise I had a sport one instead of a non sport so there was a lot of movement in the balljoint and the wishbone.

 

[olliewebbuk]

Hmmm. Are you sure you've replaced the balljoints with the correct item? I had this problem, put on the supplied balljoint only to realise I had a sport one instead of a non sport so there was a lot of movement in the balljoint and the wishbone.

Yeah I had this issue. Fitted a non-sport one without realising. Replaced with a proper item it improved things no-end. Make sure you get the bolts plenty tight too, had issues with them not being torqued up enough originally.

 

[Gaverick]

I replaced the ball joints on both sides and the other side is fine so I assume they are the right ones. I'll try tightening the pinch bolt on the ball joint see if that helps. May be time for powerflex wishbone bushes.

Thanks for the suggestions.

 

[olliewebbuk]

Check the bolts that hold the ball joints to the arm, if they are 2mm bigger than the holes in your arms then you have the wrong ones. The end that attaches to the hub is the same size, so it won't be that.

 

[Gaverick]

Just something I've noticed this morning, it seems after it has rained the knock disappears for a while, I don't know if this is just coincidence of if it could genuinely affect something.

 

[Harbinger]

Loose brake pads? check the little slider thing holding them in the Caliper.