droning noise when braking

[Andy T 0]

Sometimes when braking to a stop, there is a loud droning sound coming from one of the front wheels, which reduces as the speed does.

 

It sounds alo like alot like a wheel bearing sound, but on previous cars i've only heard this noise when at travelling speed, not when braking. The bearings make no noise at all when driving at any speed.

 

Does this sound like the wheelbearings, or could it be the brakes/driveshaft/cv/diff/gearbox???

 

btw, the brakes have drilled discs & pagid pads. Wheels are 17's.

 

cheers,

[andycowuk 0]

When you brake the weight of the car is thrown to the front, increasing the load on the bearing - so it could be the bearing on its way out. However, I found on my last golf the 500 mls before I replaced my pads, they would make a droning as they approached the last 3-5 mm of pad - must have been a built in feature.

As soon as I put new pads on, noise was gone.

[Kevin Bacon 5]

Some drilled or grooved discs cause a droning noise themselves. My old Zimmerman drilled discs and Mintex M1144 pads used to drone.

 

Worn wheel bearings normally drone during cornering and you'd get a delayed reaction on the steering, plus a very vague feeling in the steering when driving in a staight line.

 

Just another possibility.

 

Kev

[Andy T 0]

yeah, guess the drone could be vibation between the pad and disc, particularly because of the drilled holes.

 

I'm going to take the 17's off and put a set of 15's on, somehow I have a feeling that they make the problem worse. I also noticed that they don't seem to locate on the hub boss(!) there is loads of clearance, so all the forces of the wheel are through the wheel bolts, not good!

 

 

cheers

[Bruno 4]

yeah, guess the drone could be vibation between the pad and disc, particularly because of the drilled holes.

 

Andy, it is your disks. Your pads are either very hard or have become glazed. Either way as long as they dont squeak or judder or pull one way or another, or cause the ABS to flicker theres nothing to worry about.

[Andy T 0]

Cheers Bruno,

 

If the pads are glazed, what can be done? Would a good run with some heavy braking sort them out??

 

The brake feel is a bit vague, not as good as the mk2 on its little 239's.

 

Not sure about the ABS light, I've only just discovered that I've got ABS! (see ABS thread)

 

thanks,

[Kevin Bacon 5]

If the pads are glazed, what can be done? Would a good run with some heavy braking sort them out??

 

Yep!

 

The brake feel is a bit vague, not as good as the mk2 on its little 239's.

 

The G60 and VR6 got bigger Master cylinder (22? and 23.something mm respectively) and caliper pistons than the MK2 Golf 8 & 16Vs, which gives a slightly softer pedal. The Corrado brakes are a lot more effective though, even if they don't feel it on initial bite!

 

Not sure about the ABS light, I've only just discovered that I've got ABS! (see ABS thread)

 

thanks,

 

The light is there as a warning and shouldn't affect them workings of the ABS mechanics. Just stomp on the pedal on a wet road and you'll soon see if the ABS works or not!

 

Kev

[Andy T 0]

Cheers mate. yep I really need to test them properly to find out how good they are!

 

Think I will change the brake fluid first, its probably not been done for a few years.

 

cheers,

[stevemac 0]

Cheers Bruno,

 

If the pads are glazed, what can be done? Would a good run with some heavy braking sort them out?

 

If heavy braking doesn't sort them out, you'll need to take them out of the caliper. Give the pad linings a quick rub with some fairly rough emery cloth, coat the back of the pads with copper grease & re-fit them onto the car. Allow a few miles to (cough) "bed" them back in.

[Andy T 0]

Cheers, I might end up doing that. The pds look clean as if no Copper grease has been used.

 

How difficult is it to change the front pads? I'm mechanically minded, just haven't touched brakes yet, apart from bleeding the braking system on my mk2.

 

thanks,

[stevemac 0]

Fairly easy to do. Just remove any pad retaining clips & pins from the calipers & the pads should just slide out. Loosen the brakefluid reservoir cap (don't remove it completely) and lever the caliper pistons back into the calipers a bit. Roughen the pad linings a bit with emery cloth. Spread plenty of coppergrease onto the back of the pads and re-fit everything back together. Tighten the reservoir cap & pump the brake pedal a few times to push the pistons back into position. You won't need to bleed the system as no air will have entered it. The pads will take a few miles to bed in properly.

[Andy T 0]

Right, I still have this front brake problem, but I need to sort it this weekend!

 

I'm thinking of replacing the 'pagid' pads with a set of Pagid FR, rather than try and resurrect the old pads.

 

Only thing i'm worried about is that the drilled disks could be causing the problem - I have no idea who they are made by!

 

I've also noticed, with the windows down, that the front brakes are very noisy even when slow/light braking (cant be the tyres because I had the same tyre on my mk2) :roll:

 

Should I try a new set of pads both first, or should I junk the lot, and get some VAG disks? Could the new pads go the same way if used with drilled disks?

 

I like to do a job once rather than 5 times if you know what I mean! :)

 

and finally, how many miles to break the new pads in properly?

 

 

cheers

[aide 0]

Had an intermittent vibration problem a year ago with standard pads and disc setup. So decided to change with cross drilled pads and pagid fast road pads like you've got - then I got the droning problem :!: Tends to happen when rapidly braking, and resonance of drone gets deeper the harder and longer the braking is, that said the brakes are damn site better than the original set up so would stick with em if I were you, and since I had the full tracking checked the problem is definitely occuring less. I'd change the pads and discs for new and see what happens, G&S do all the kit - don't forget copper grease on the back of the pads though :D

 

Advice on previous link is obviosuly very sound, your 'hub to wheel' gap sounds a bit hairy though!!!!

 

I guess its a case of suck it and see :roll:

[stevemac 0]

Get yourselves some drilled Brembo front discs from German, Swedish & French. I've had them on my G60 for about 7k now - totally silent, no droning at all. Cheaper than original VAG ones too. 8)

 

I agree with aide about the wheels though - fitment sounds a bit strange. 17" wheels won't usually cause a problem, so long as they fit properly.

 

Also check your rear wheel bearings as these drone quite loudly when they're worn. Unlike the front ones, the rear bearings will drone constantly wether cornering or in a straight line.

[Andy T 0]

Tends to happen when rapidly braking, and resonance of drone gets deeper the harder and longer the braking is

 

Thats exactly the problem I am getting! I assumed the increase in noise was dues to them heating up. It gets so loud that ppl look round at you expecting your car to blow up !

 

So maybe its just a problem with certain types of drilled disc's - what disc's are you running Aide?

 

It turned out that the 17's were ok, they were actually on spigot rings that were the same colour as the hub! Anyway its on 16's now that are a proper VW fitment.

 

The Brembo discs sound good, maybe I'll swop to those eventually. The rear bearings are ok, nice and quiet.

 

It seems to be coming more from the offside wheel, I might just take the o/s disc off first and make sure the mating faces are totally clean, then try with new pads, plenty of Copper grease of course 8)

 

cheers

[aide 0]

So maybe its just a problem with certain types of drilled disc's - what disc's are you running Aide?

 

eerrr a mate bought them for me about a year ago from German & Swedish as i didn't have time, they didn't come in a box :!:

 

They're fairly distinctive though - Due to the fact there is no discernable pattern!! Unlike other cross drilled pads which usually have the holes in groups or curved lines.

 

Do these sound like yours?

[kongo127 0]

I am pretty sure of bad bearings!

You can find a cheap kit of both of them on http://www.ebay.de

[Andy T 0]

Pretty sure the front bearings are ok- they were replaced about 30k ago. Theres no rumbling when fast cornering so they should be ok!

 

Does anyone know the size of the Hexagon key/socket required for taking the caliper bolts out?

 

Think i'll go and get a proper hexagon head socket drive rather than chance it with an allen key :)

 

 

Cheers

[Andy T 0]

ignore that I was talking crap, its a 13 & 15mm spanner isn't it!

 

Will the discs come off without removing the pad carrier, if not, what sockets do I need to take it off?

 

cheers,

[dazzyvr6 0]

if its the front bearing you will need to get them pressed in,i think the caliper bolts are 8mm allen type bolts

[Andy T 0]

Not touching the bearings, just gonna change the pads and take the discs off to take sure they were seated cleanly on the hub.

[Andy T 0]

They're fairly distinctive though - Due to the fact there is no discernable pattern!! Unlike other cross drilled pads which usually have the holes in groups or curved lines.

 

Do these sound like yours?

 

Mine are in straight lines - the pattern is 3 holes/2 holes/3 holes and so on.

 

 

I took one of the front wheels off today, to have a look at the brake disc.

 

Both sides of the disc were unevenly worn, in bands. The bands were inline with and the same width as the drillings, so it seems that the drilled holes are causing the disc to wear unevenly.

 

It's hard to describe, but every other 'band' had worn more than the one next to it, by about 0.5-1mm.

 

So maybe the uneven disc surfaces are causing the vibration when they heat up and expand slightly? :?

 

 

German & Swedish don't list any brembo discs for the G60 now - shame because Brembo MAX look great (6 groove with a phosphate finish)

[Kevin Bacon 5]

Where they on the car when you bought it? They sound suspiciously like Zimmerman drilled discs as those lateral grooves you describe are put there deliberately. They are shite discs and explains the droning your getting as I used to have some many moons ago....

 

K

[Andy T 0]

Yeah unfortunately they were on it when I bought it, and there's no receipt for front discs's.

 

The holes are badly corroded so the pads are probably picking up hard chips of rust which cant be helping much!

 

What have you changed to now Kev?

[Andy T 0]

Is anyone using ATE power discs? They sell them at Euro car parts, and have two continuous grooves in them that overlap 3 times around the disc face.

 

Any good? I'm I right in thinking that ATE make VW's OE brake disc's, so the quality should be bang on?

 

 

cheers