Slight Judder When Braking

[Keith Bowler]

Noticed recently on motorway when I break smoothly from about 90 mph down to about 50 mph I get some slight judder from the front wheels.

I think I may need new pads and possibly disks which I assume is the problem due to extra play in the calliper operation and worn disks beginning to warp.

If my diagnosis is correct I would like to get some cross drilled and grooved disks.

Any advice as to where to look and what would be best combination of disk and pad to use. The car is a Mk1 Gs and runs on standard sport wheels and has had no similar problems to date.

[eXOBeX]

Firstly, borrow a torque wrench and tighten the wheelnuts to the correct torque, in the correct order! Out-of-order nut tightening messes up discs on the GS.

[grafter]

I had exactly the same with mine a few weeks back mate. Meant new pads and disks for me as the old ones were well worn. Even had to have standard cr*p cause of the ex

Just letting you know mate.

[Rodders_UK]

it's gonna be the discs mate - they seem to warp very quickly on the GS.

I've tried a few different ones, I'm using Mintex now and I'm pretty happy with them

[gsportcars]

Hey mine is very similar although not obtrusive on my IS. Kinda worrying still as I have uprated discs on the car already!

[crazylex]

Hey mine is very similar although not obtrusive on my IS. Kinda worrying still as I have uprated discs on the car already!

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See this thread it could be a sticking caliper on your IS. Maybe even on the GS - I think the pads are the same so maybe the calipers are.

[Keith Bowler]

Thanks guys

I don't think its calipers as they seem to operate fine.

I suspect discs, as there is a ridge around the outer lip of the discs of over 1mm or so.

I want to try some cross drilled and grooved discs so will probably giving the guys at prolex a call.

I will check wheels this weekend as alas can't get to JAE. I am going to repaint my calipers from gold to red which I think will look better in contrast with my dark blue paintwork.

Can anyone let me know what the correct torque setting is for the wheel nuts and the sequence for tightening them.

[Keith Bowler]

Thanks guys

I don't think its calipers as they seem to operate fine.

I suspect discs, as there is a ridge around the outer lip of the discs of over 1mm or so.

I want to try some cross drilled and grooved discs so will probably giving the guys at prolex a call.

I will check wheels this weekend as alas can't get to JAE. I am going to repaint my calipers from gold to red which I think will look better in contrast with my dark blue paintwork.

Can anyone let me know what the correct torque setting is for the wheel nuts and the sequence for tightening them.

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Just seen an earlier post from Colin regarding the last sentence of my post.

[Peter L]

Trust me when I say this but when I had my MK1 GS Sport, I kept getting brake judder despite changing discs and pads 3 times within a space of 6 months. The OEM ones just aren't up to stopping a big heavy auto without warping. I changed them with the DBA drilled and grooved ones which were part of a group buy from Mark at Torque Developments and with standard pattern pads - were the dogs danglies ... not only did they not warp or fade they felt solid and stopped sooner ... may have been even better with Mintex or another decent set of pads. Even when a caliper siezed and clamped down so that the discs got WHITE hot .and everything else melted/knackered, the discs just needed cleaning up and worked faultlessly, no cracks/warping ... I'm thinking of getting a set for my IS 200 Sport even though the OEM ones seem more than up to the job ...

Hope this helps ...

[LAURIE MILLS]

Trust me when I say this but when I had my MK1 GS Sport, I kept getting brake judder despite changing discs and pads 3 times within a space of 6 months.  The OEM ones just aren't up to stopping a big heavy auto without warping.  I changed them with the DBA drilled and grooved ones which were part of a group buy from Mark at Torque Developments and with standard pattern pads - were the dogs danglies ... not only did they not warp or fade they felt solid and stopped sooner ... may have been even better with Mintex or another decent set of pads.  Even when a caliper siezed and clamped down so that the discs got WHITE hot .and everything else melted/knackered, the discs just needed cleaning up and worked faultlessly, no cracks/warping ... I'm thinking of getting a set for my IS 200 Sport even though the OEM ones seem more than up to the job ...

Hope this helps ...

←

Just had my front brake rebuilt (see previous post), and the rear of the discs were badly rusted, and were barely in contact with the hubs. My judder was pretty bad, and I had bought the discs anyway, so changed them, but had the hub faces thoroughly cleaned and given a liberal coating of copper grease to ensure no return of the corrosion.

My mechanic also spotted a siezed caliper piston, and rusted slide mechanism, prompting my rant over the effeciency of Lexus's (gold plated) service regime. In fact my man chris felt that the corrosion and caliper/slider problems were far more likely to be the cause than any torque issue, although I made sure the torques and tightening oreder were 100% as per Colin's post anyway.

BTW they now work very well. When you compare the specification (diameter, ventillation, pistons etc) with the brakes on a BMW 5 Series (the GS's natural target) they are at least as well specified, so I would question the previous comments about the brakes not being up to stopping such a big and heavy car. Having owned both I would suggest that the character of the BM would lead it to need more hard braking than a wallowy. comfort biased GS300, yet such an experience in a 5 series is rare indeed (I have owned 5 so far|). My view is that shoddy replacement cleaning/greasing regimes lead to this problem on higher mileage GS300's.

Comments welcome

[Tron20]

Intresting topic, I've got a slight judder aswell on a 63k 1997 P reg GS300 sport, recently changed the front pads, but suspect a warped disc or two, any how, i'm still gonna check all the caliper pins, and caliper pistons for play/binding, might be worth a shot before i purchase costly discs for no reason.

Just curious, but does anyone know how to check the drum brakes on the back of a gs300, i think mine are either wearing thin, or are sticking a little, as i get a scrappng noise from somewhere as i'm moving along, not a loud noise, but still evident when driving near a crash barrier on a dual carriageway when travelling slowly