Brake queation

[Nightsman33]

Hi guys.

Abit of a stange one but when i brake hard it feels like the wheel is moving back and fore as im pressing and releasing the brake and there is a slight thud if that makes sense.
I have changed all suspension ball joints etc also had new discs and pads and calipers are all fine.
I have jacked it up and cant feel no play in the wheels etc.

Any ideas please
Many thanks

[marti]

Caliper bolts tight enough?

[Nightsman33]

Yes mate checked everything twice.

[X5Sport]

It may not show without ‘load’ on the suspension (as in weight-on-wheels), and use a something like a pry-bar to see if anything joints wise moves that shouldn’t. It could just be that once the weight came on something settled and isn’t as tight as you thought.

[Nightsman33]

It may not show without ‘load’ on the suspension (as in weight-on-wheels), and use a something like a pry-bar to see if anything joints wise moves that shouldn’t. It could just be that once the weight came on something settled and isn’t as tight as you thought.

I will take another look at it. Many thanks

[Themoog2]

Front lower thrust arms rubber Bush knackered I reckon.

[Nightsman33]

Front lower thrust arms rubber Bush knackered I reckon.

Is that the arm that fits into the ball joint mate

[Themoog2]

It’s got a ball joint on it yes. It also has a big rubber bush nearly in the front bumper. When that rips it wobbles about and can give those symptoms you mention.

[Nightsman33]

Am i better off replacing the arm or just changing the bush
Thanks mate

[Greydog]

Depends on whether you have a really good bush removal tool or a press those bushes are in there really tight. If you cut them out you could replace them with poly-bushes. Whether you use convectional or poly-bushes when tightening make sure the car is on ramps loading the suspension. If you don't the bushes will be under tension and fail early. When I did this job I changed the arms but the lower ball joint was also on it's way out and the only way to describe that job is it's a grade "A" Beeeeeeech of a job, not BMW's best engineering design
I had read that this was not a good job. So I cleaned around the top of the ball joint made a wall of plasticine around the edge and flooded it with release fluid left it for a couple of days to soak in then with arm in place and a really big hammer wacked down on the arm. Passenger side worked using this brute force attack. Drivers side it just pulled the ball from the joint and didn't move the housing at all. I ended up using a grinding burr on the wall of the housing then collapsing it with a chisel even then it needed stilsons on the mounting bolt ears before it gave up!!

Good luck

[Nightsman33]

everything has been changed apart from that bush both sides so all will be loose as it was only done recently. Only reaaon didnt change them bushes or arms as they looked quite new but live and learn il get them changed asap. The ball joints was bad to come out but they did come out whole and not fall apart lucky enough Thanks again for the help.

[Greydog]

I did the job on my first X5 (4.4) and tightened everything up with the front jacked up. The bushes failed in about 5k as when the car is back on it's wheels the bushes are twisted and under strain. That is when I learned to change them put the bolts back loose then wheels on and drive the car onto my ramps which give enough room underneath to Torque the bolts up