Pulling left under high speed braking. Solved

Z4 Gaz

Member
 South Hams
Only does it at higher speeds, around 60 and above, even when only braking gently.

The car has new Meyle wishbones and Lollipops.
All caliper sliders are free and greased.
Checked the front right caliper piston and that is free from rust and moving fine.
Discs and pads are good all round.
All new suspension.
Track rod ends have no play that i can see from beneith or feel when moving the wheels or pulling on them.


What am i missing here that could be causing this?

I re used the top mounts when doing the suspension as the bearings were tight with no play, so i just re greased them.
 
Pedal feels firm, but will try bleeding the drivers side to see if that makes any difference.
 
May be a silly question but are these tests on the same road or different roads?

I had a road near me that I had to fight to keep straight under breaking.. only done it on that stretch of road though...
 
coupedan said:
May be a silly question but are these tests on the same road or different roads?

I had a road near me that I had to fight to keep straight under breaking.. only done it on that stretch of road though...

It's everywhere.

jamie_z4 said:
You only checked the right caliper?

Yeah, pulling left would suggest the front left caliper is working harder than the right, hence the car trying to rotate to the left, assuming it is even brake related, meaning it would have to be the front right caliper that was sub optimal. Non of the calipers are sticking though.
 
Wheel alignment?

If you have had new wishbones/lollypops next to check is the steering tie rod ends which would have been undone... then done up again which could have thrown out the tracking/camber
 
Was doing it before the wishbones were changed, I also didn't remove the TRE's when I changed them.

Doubt it is alignment related as it is perfect apart from high speed braking when there is a pronounced pull to the left. Full set up was done recently too.
 
Round 2 for other thoughts
- tyre pressures
- dodgy shock absorber / cracked spring
- worn ARB drop links
- broken main ARB clip
- fractured ARB
- worn tie rod ends
 
Jembo said:
Round 2 for other thoughts
- tyre pressures
- dodgy shock absorber / cracked spring
- worn ARB drop links
- broken main ARB clip
- fractured ARB
- worn tie rod ends

Pressures fine, ARB fine, tie rods seemingly have zero play, shocks, springs, arb links and bushes are new :lol: This is why it is so strange.

Once I have bled the brakes I will report back, but may just change the TRE's anyway to make sure.
 
Blimey... looks like you took the journey I made with my old 3.0SE, though at each change it improved as I did 1 by 1

Good hunting
 
Bled the brakes on the drivers side front and back, no air came out.

Took the car for a quick drive into town, when I got back I put the infra thermometer on the back of the pads. The near side pad was 20c hotter than the off side, so for some reason the OSF caliper isn't working as hard as the NSF. Hopefully this is the cause of the issue and not a result of.
Rather than rebuild the calipers I am going to go for a 325mm upgrade. Now I just need to source some cheap SI or e46 330 front calipers.
 
After changing the front calipers for used ones from an E46 330 along with new discs and pads the problem is solved.

Why I don't know, as the discs and pads were in good, barely worn condition, the pistons are rust free and the slide pins greased and moving freely.
 
Sounds a bit strange, but at least the problem is solved! :thumbsup:
 
I have exactly the same issue with the M. Started about a year ago but up to about 60 mph, you wouldn't notice.

I will drop it off at my local specilaist and see if he can sort it.
 
Congrats on the fix! Mine pulls left a bit when braking at higher speeds too. Rear discs were shabby so I replaced those. Next stop was wheel alignment. I booked the car in with a respected Mercedes specialist in North Somerset for Hunter alignment. They charged me £78 even though they made no adjustments having discovered that a special tool is needed for rear wheel alignment. When I mentioned the behaviour under braking and said that I hadn't inspected the front brakes yet, there was a bit of a sly remark from them to say "your tracking makes a car pull sideways, not your brakes". Needless to say I won't be going back there...apart from to get my money back :)
 
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