Knocking on braking

[chriz1]

Hi my berlingo front wheel bearing was shot so I managed to find a copy new hub complete with wheel bearing on ebay. Fitted to today and on braking there's a knocking noise coming from that corner no vibration or noise during driving only when braking, ive taken calipers discs and carriers off and cleaned all faces and surfaces it's more than a judder it's a faint bang / knocking noise.
I can't understand what's causing it I'm starting to suspect the replacement 'cheap' hub isn't running true and it's only highlighting itself when braking.

Any thoughts guys?

[stevieturbo]

And how exactly would a hub that is not true, cause knocking ?

You've done something else

[chriz1]

I was thinking in the same way a brake disc not sitting flush to the hub or warped would cause a knocking / judder.
If the hubs not running true this will cause the disc to judder and knock no?

[stevieturbo]

chriz1 said:

I was thinking in the same way a brake disc not sitting flush to the hub or warped would cause a knocking / judder.
If the hubs not running true this will cause the disc to judder and knock no?

I have never ever had an out of true brake disc cause a knocking. A judder, a bumpy pedal etc yes, but never knocking.

Either something is loose, or fitted incorrectly.

[chriz1]

It probably is a really bad judder not what i have experienced in the past mind, more of a knock but only when braking,can't understand what can cause that other than disc not sitting correctly

My plan tomorrow to get a replacement bearing pressed in to the old hub and refit.
What I should have done in the first place tbh but at the time it was easier to get a complete new hub delivered to the house and fit.
This will at least confirm if the cheap replacement hub is naff.
Will post back tomorrow

[E-bmw]

stevieturbo said:

chriz1 said:

I was thinking in the same way a brake disc not sitting flush to the hub or warped would cause a knocking / judder.
If the hubs not running true this will cause the disc to judder and knock no?

I have never ever had an out of true brake disc cause a knocking. A judder, a bumpy pedal etc yes, but never knocking.

Either something is loose, or fitted incorrectly.

Listen to this man, don't try to invent issues that are not there.

[cuprabob]

Could it be the pads moving in the caliper. Are the anti-rattle springs fitted? Are the in good condition? The only other thing I can think of is a drop link not torqued up correctly but I wouldn't have thought you would have needed to remove that to change the hub.

[Dave Brand]

cuprabob said:

Could it be the pads moving in the caliper. Are the anti-rattle springs fitted?

That was my first though.

Having said that, I had a similar problem on an Alfa 145; turned out one of the horns had dropped off & was hanging loose inside the front bumper!

[chriz1]

Right had a new nearing pressed into old hub, fitted all back and all good! So must be the new hub isn't square or running true that will teach me to use cheap parts to try make my life easier

[cuprabob]

chriz1 said:

Right had a new nearing pressed into old hub, fitted all back and all good! So must be the new hub isn't square or running true that will teach me to use cheap parts to try make my life easier

Or you put it back together better this time. Either way it sounds as if it's fixed