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Vibrating under braking


-Chris-

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All,

 

Looking for a bit of advice. My cart has just come back from Lockwood and Greenwood where it had a P3 and braided brake lines fitted.

 

I drove home in rush hour to find I had flat tyre when I got back. I had this repaired yesterday and then noticed a vibration under braking at higher speeds. This morning I got up and when had the wheel re balanced but this has not solved the problem.

 

I have done a a short bedding in procedure (it was during the day and not safe to do more than 5 stops in a row) but the problem is still there.

 

I have read about DTV but how would this occur when in the garage?

 

Thanks for the help/advice in advance and please excuse any typos I'm posting from my phone.

 

Chris.

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If its only happened since the car has been in, get it back there and get them to look at it.

 

DTV develops over many many miles. They could have made it worse if they removed the discs and didnt put them back on the same, but they dont need to remove discs to replace lines.

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Was the wheel balanced on the car or off - if the latter that might be the problem if your were not getting the vibration prior to the puncture and I presume you did not notice anything on your way back from L & G.

 

As L & G have a good reputation on here you might be best off going back there to see what they say/can do ;)

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I get this when braking from 50+ but iv put it down to the fact the brakes are drilled and slotted (as i have never had them before so dont know if its supposed to :lol: ) but doesnt vibrate when slowing from under 50.

 

You shouldn't get any vibration no matter what sort of discs you have.

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the problem may be more apparent now, now you've had your braided lines fitted. I had the same issue. The discs aren't touched when fitting the lines so its just something that is now more obvious. I ended up changing my discs as they were quite weathered over winter low usage and the build up of rust on the inner disc was heavy causing uneven wear.

 

The other thing to perhaps consider is your front bushes. They may be split. I also found this issue. ZMANALEX can supply these

 

Changing the discs and pads will now doubt cure the issue. It did for me.

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I get this when braking from 50+ but iv put it down to the fact the brakes are drilled and slotted (as i have never had them before so dont know if its supposed to :lol: ) but doesnt vibrate when slowing from under 50.

 

 

Mine vibrated at the higher end of speeds due to winter weathering and low usage, as they got hotter the vibration would come down in speed. Do a good bedding in procedure to see if it cures it. If not its time to replace discs and pads I'm afraid.

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Was the wheel balanced on the car or off - if the latter that might be the problem if your were not getting the vibration prior to the puncture and I presume you did not notice anything on your way back from L & G.

 

As L & G have a good reputation on here you might be best off going back there to see what they say/can do ;)

 

The wheel was balanced off the car (I didn't realise it could be done on the car) but I don't quite see how that would cause the problem? It was also the rear wheel that had the puncture and the vibration feels like it is coming from the front more. The wheel has also been balanced twice now - once on sat when the puncture was repaired and again today at a different garage as I thought that may be the problem.

 

I didn't notice the vibration on the way back from L & G but it was rush hour so wasn't going very quickly (although I did use the motorway). Could a puncture repair really cause this issue?

 

I'm going to take the car back to L&G tomorrow to see what they say but I need it sorting

this week as I am attending RAF Valley next weekend for the airfield day.

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Ok,

 

The car has been back to L&G today for them to investigate. They have inspected the brakes and found there to be slight run-off on the nearside disc.

 

The only explanation they can suggest as to why the vibration is their now and wasn't there before is the braided brake line and upgraded fluid. They are suggesting that the previous brake lines and fluid were absorbing this vibration and the new more set up is transferring this vibration.

 

Before the car went in the brakes worked perfectly and I had no problems at all with vibration. Now the vibration causes the dash to vibrate when braking and is worst at ~40mph.

 

I would be very interested to hear if people think this is plausible?

 

Chris.

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as I said in my post earlier, they're correct and most definitely plausible. The guys at L&G are good are not just out to rip you off. The vibration is definetly caused by the disc and isn't touched when installing braided lines. As they and I pointed out, this issue rises when you have braided lines fitted. It did with me and new discs and pads solved the problem. I also had my lines fitted by L&G for the record but had the discs fitted independently.

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Thanks for the reply M13KY.

 

I use L&G due to their good rep on here and have always been very impressed with the service and the work they have done.

 

Personally it feels the difference before and after is too significant to just be the new lines and fluid but it appears I am wrong - you learn a new thing every day!

 

I will order some new discs and pads as suggested.

 

Thanks to all those who posted.

 

Chris.

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Before you go and order new discs and pads, see if L&G will skim the disc for you. Agree that if it is the runout then you will pay for it (I would push to have it done at cost) and if it doesnt fix it then its up to them to find the solution. I agree with Mike in that it is likely to be fresh fluid and braided lines that is highlighting this fact, and if they beleive that this is the case, they should do the skimming for you if there is enough meat left on the disc. Nothing for them to loose if that is the real cause as you will pay for it, and if its not then they cant hide behind it :thumbs:

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Hi All,

 

Thought i would post a quick update on this. Had the front discs skimmed last week but this has not solved the problem.

 

The problem is definitely related to heat - the brakes are fine when cold but the vibration gets worse the hotter they get. After the getting the discs hot they did not look very healthy either - the disc was covered in what seemed to be brake dust and there were several shadows after each grove (EBC drilled and grooved discs). A short drive yesterday where the brakes didn't get hot cleared most of this from the disc so it points to he problem being the front discs, rather than the rears which were not skimmed.

 

I think I now have no choice but to replace the front discs.

 

The only other thought i had (and please tell me if this is daft i am clutching a straws a little here!!) is that 2 nipples where seized when the brake fluid was replaced (can't remember exactly which ones but NSF and OSF i think). Could this mean there is still the old standard brake fluid in part of the calliper and as it heats up it is reacting differently to the new brake fluid and putting uneven pressure on the pad causing it to vibrate?? The fact both front discs are showing the shadow and brake dust doesn't support this though.

 

Anyone have any thoughts or should i just get my wallet out and buy new discs?

 

Thanks,

 

Chris.

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What pads are they out of curiousity? I'm personally not a fan of ebc, but apparently they've changed their compounds at least.

 

May be worth just trying some different pads rather than discs as well.

 

I had issues with yellowstuff on drilled rotors, but maybe you'd be ok with their newer compounds? However, personally from that experience and seeing some pictures of pads disintegrating I'd be trying something else like ferodo/endless/performance friction/dixcel.

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I agree with you on EBC products - when i brought the car it had EBC yellow stuff pads on (with the disc i have now) but when i needed to replace my rear brakes i also changed the front pads to Ferodo DS2500 and they have been a big improvement.

 

L&G have been great and asked to check the car over once more before I coughed up for new discs and pads. they have cleaned up the hub and checked the current discs are seated correctly as well as double checking the fluid they replaced at the service. The problem is still there though. :bangin:

 

I have now ordered DBA discs and Ferodo pads from ZMANALEX so will place these over easter and hopefully the problem will be solved!

 

I will update this post in a week or two after I have fitted and bedded them in.

 

Chris.

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same issue as I had and stated earlier. Get some new discs and pads and the problem will disappear. I went for DBA4000 with ferodo DS2500 pads. No vibrating issues now. Need I repeat myself again

 

He's already said he's ordered new discs and pads? :wacko:

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same issue as I had and stated earlier. Get some new discs and pads and the problem will disappear. I went for DBA4000 with ferodo DS2500 pads. No vibrating issues now. Need I repeat myself again

 

He's already said he's ordered new discs and pads? :wacko:

 

 

oh eye, missed the last post :oops::sorry:

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Could it be some contamination on the discs causing a difference in friction as the disc rotates? I had similar issues when using ferodo ds2500 pads on-track, the pads transferred onto the disc in places, leaving shadows of the pad outline on the disc causing vibrations. But then if you have had them skimmed this should have solved this.

 

Yellowstuff`s all the way for me

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