LS430.. Knocking sound after brake job.. HELP

[Abid221]

Hello

I decided to demonstrate my DIY skills to my second half and followed the tutorials on here and changed the front pads and discs myself. 

I went for a test drive. However I can hear a knocking sound which I'm sure is coming from my DIY brake job.. 

What do members think it is? 

I don't want to drive the Lex because I feel it might be dangerous. 

Thanks 

[GrahamG]

Have you checked on Youtube?

I replaced my rear discs and pads but only after studying the available videos.

Good luck

[Connor2x4]

You need to specify when it happens, asking generic questions is going to give you generic answers. Does it only knock when you press the brake? Does it do it when you let off the brake? When you push hard/soft?

 

 

I'm guessing it's only happening when your pressing on the brake at speed (10/15mph+) I would suggest double checking that you have tightened the carrier bolts to the hub, as these do need to be really tight.

 

If that's not the case you'll need to report back after a short test drive and put down the specifics as to when the knocking occurs.

 

Hope this helps

 

 

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[Abid221]

7 hours ago, Connor2x4 said:

You need to specify when it happens, asking generic questions is going to give you generic answers. Does it only knock when you press the brake? Does it do it when you let off the brake? When you push hard/soft?

 

 

I'm guessing it's only happening when your pressing on the brake at speed (10/15mph+) I would suggest double checking that you have tightened the carrier bolts to the hub, as these do need to be really tight.

 

If that's not the case you'll need to report back after a short test drive and put down the specifics as to when the knocking occurs.

 

Hope this helps

 

 

Sent from my SM-G960F using Tapatalk

 

 

 

 

The knocking occurs when I'm driving on low speeds at around 20-30mph. I tightened the 2 bolts as tight as I could. 

 

[Connor2x4]

The knocking occurs when I'm driving on low speeds at around 20-30mph. I tightened the 2 bolts as tight as I could. 
 

I had a similar problem once and it was down to those carrier bolts. It was like a slight clunky everytime I pressed the pedal at around those speeds. I personally found it quite difficult to get the torque required on the bolts when it was jacked up, on the 400 I'm sure its about 88NM.

If you have a torque wrench and can wait till tomorrow I'm happy to find the correct torque setting for these bolts and its something you can eliminate from the equation

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[DaKa]

I changed my front pads/discs about a year ago without issue.

Assuming you definitely bought the correct pads/disc, a clunk normally suggests that the pads are not a secure a they should be. You must check they they where locked back in securely and all bolts tightened to a torque of FT.

May I suggest if this is new to you to take it to ATS or KwikFit for a free brake test (suggest to them that you may ask them to fit the rears?) - I'm sure will help.

 

[GrahamG]

At risk of sounding like a school prefect, the carrier bolts should be renewed with the discs and all bolts need tightening with a torque wrench. If you do not need a torque wrench you would not be asking advice.

Noises from brakes may be associated with shims and that is one reason I recommended watching Youtube videos to establish if they are all present and in correct order.

Please be careful, if my brakes were making any noise after servicing I would be terrified.

[Abid221]

Resolved the issue. 

Thanks to a member's advise who told me to check my wheel nuts.

I checked my wheel nuts. And omg guess what? some were loose! 

So I tightened them all and the knocking is now gone. 

Thank god the tyre didn't come off. 

 

 

[Connor2x4]

Resolved the issue. 
Thanks to a member's advise who told me to check my wheel nuts.
I checked my wheel nuts. And omg guess what? some were loose! 
So I tightened them all and the knocking is now gone. 
Thank god the tyre didn't come off. 
 
 

They must have been really loose, whenever mine have been slightly loose you can feel a faint hum at any speed through the steering wheel.

Also the tyre and wheel are two different things dont forget!

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[Texas]

Gotta say when I read the 'cause' of this thread's posting I was a bit horrified....wheel nuts loose!!!!! Sorry but that is quite basic.

please don't let your confidence exceed your competence when working on your car cause you could be driving somewhere near me!

paul m.

[Abid221]

19 minutes ago, Texas said:

Gotta say when I read the 'cause' of this thread's posting I was a bit horrified....wheel nuts loose!!!!! Sorry but that is quite basic.

please don't let your confidence exceed your competence when working on your car cause you could be driving somewhere near me!

paul m.

I guess I'll have to just leave it to the experts next time. 

But yes that's was pretty stupid of me. 

[Cotswold Pete]

Adam,

Do not beat yourself up, I have had wifes car with loose wheel nuts (done by a garage), and I almost did it myself a few years back  (go distracted once I had dropped tyre on road), and being a bit paranoid checked my wheels after 10 miles to discover had not tightened up 3 of the nuts.

So I now check then double check, and as I work a lot with electric at 240 volt, just get into the habit of being paranoid, as 240 volts tneds to pack you off to heaven pretty quickly.

Your skills are fine as changing brakes though not difficult does need a level of cpability which sounds like you have.

[ambermarine]

13 hours ago, Abid221 said:

I guess I'll have to just leave it to the experts next time. 

But yes that's was pretty stupid of me. 

I agree with Pete mistakes are only made by learning from experience ,If you want to avoid this issue in future tape a notice to the inside of your hubcaps in red letters "Tighten wheel nuts" this will cover all instances when wheels are off punctures etc.

[RgrWynne]

32 minutes ago, ambermarine said:

I agree with Pete mistakes are only made by learning from experience ,If you want to avoid this issue in future tape a notice to the inside of your hubcaps in red letters "Tighten wheel nuts" this will cover all instances when wheels are off punctures etc.

So you don’t forget, the wheel nuts should be torqued to the manufacturers spec, for which you will need a torque wrench, this might remind you.

[ambermarine]

Roger

I have to point out that the requirement for a torque wrench is not strictly true the wheel brace in the toolkit of the LS is adequate to undo the wheel nuts if used to tighten them up and that tightness is achievable with the wheel brace .

To that end the design of the wheel brace as been thought out to create the safe torque for manual application,sometimes the tyre garages use power wrenches that are set too high this can result in snapped lugs whilst driving especially on steel wheels and the impossible task of undoing the nuts in the case of a puncture with the vehicle supplied wheel wrench.

[RgrWynne]

25 minutes ago, ambermarine said:

Roger

I have to point out that the requirement for a torque wrench is not strictly true the wheel brace in the toolkit of the LS is adequate to undo the wheel nuts if used to tighten them up and that tightness is achievable with the wheel brace .

To that end the design of the wheel brace as been thought out to create the safe torque for manual application,sometimes the tyre garages use power wrenches that are set too high this can result in snapped lugs whilst driving especially on steel wheels and the impossible task of undoing the nuts in the case of a puncture with the vehicle supplied wheel wrench.

Thanks Phil, that does make sense. It is just that I always insist on tyre depots torquing to manufacturers specs which I check. Having said that I have not had to use the supplied wheel brace, thank goodness......Sod’s law I now get a puncture, Rgds, Roger

[Abid221]

9 hours ago, Cotswold Pete said:

Adam,

Do not beat yourself up, I have had wifes car with loose wheel nuts (done by a garage), and I almost did it myself a few years back  (go distracted once I had dropped tyre on road), and being a bit paranoid checked my wheels after 10 miles to discover had not tightened up 3 of the nuts.

So I now check then double check, and as I work a lot with electric at 240 volt, just get into the habit of being paranoid, as 240 volts tneds to pack you off to heaven pretty quickly.

Your skills are fine as changing brakes though not difficult does need a level of cpability which sounds like you have.

Yeah I guess learn through mistakes. 

I'm actually thinking of changing the engine oil next. Shouldn't be difficult. 

Thanks guys.