Steering Vibration Diagnosis

[Disca]

Hi all

Figured I would wrack your knowledge to see if anyone can point me in the right direction!

Symptoms:
- Intermittent steering vibration while driving
- When braking it sometimes feels like 3/4 of the rotation it brakes and then 1/4 doesn't, still stops fine though.
- N/S/R brake disc has a slightly smaller shiny surface than other side, possibly starting to seize?
- Burning smell when I stopped the car after a 20 min drive today, more like a clutch smell but 95% sure I wasn't burning the clutch out!

Half the symptoms could be unrelated but thought I'd list the known issues to see if any could help.

I had the wheels balanced yesterday so they are all correct.
Previous owner changed all bushes five years ago.

Go!

 

[Davyhoogy]

I recent had new tyres all round, balanced wheels and tracking, and my vibrations were cured, but I also asked them to fit my brake pads and he said front offside piston was almost seized on so could be possibly a caliper issue?

 

[andyglym]

Sounds like a sticking/seized caliper to me. You can get them from Eurocarparts for a good price, I've just purchased one for just over £40 after a 30% discount in a sale.

 

[Disca]

Is there a good way to diagnose which is sticking, if one is

 

[andyglym]

Is there a good way to diagnose which is sticking, if one is

Jack up the front and spin the wheel I would suggest? That aside the disc/wheel will be too hot to touch after a short while with lots of break dust.

 

[GazHyde]

That aside the disc/wheel will be too hot to touch

Just to make a slight amendment to Andy's post, the disc will always be too hot to touch to the point at which you will lose the skin on your fingers - so don't.

However as he points out the actual wheel will tend to heat up with the excess temperature caused by a stick caliper. You can touch the wheel (carefully), and if it's really hot then caliper makes sense.

Smell wise, a stuck caliper baking brake pads will smell like clutch. I had this last time the caliper stuck on my Z3, but as the clutch was going I nearly ignored it.

Your symptoms listed do suggest a binding caliper!

 

[Disca]

Right I can confirm its the NSF caliper based off the temperature of the alloy when I got home.

Question is... what do I do next as I have 0 idea
Could source the parts if I knew what I needed and then see if a mate wants to fit it for me, or I'll take it to Birds Iver / Munich Legends and get them to do it for their lovely costs.

The NSR caliper is also still questionable due to the smaller contact surface, but it's 100% the front that is sticking at present.

 

[andyglym]

Right I can confirm its the NSF caliper based off the temperature of the alloy when I got home.

Question is... what do I do next as I have 0 idea
Could source the parts if I knew what I needed and then see if a mate wants to fit it for me, or I'll take it to Birds Iver / Munich Legends and get them to do it for their lovely costs.

The NSR caliper is also still questionable due to the smaller contact surface, but it's 100% the front that is sticking at present.

Just Google for example;
Eurocarparts and look under brakes post typing in your reg to the screen that presents itself and the parts for you car will come up under brakes. This is for mine a 98 2.8

 

[GazHyde]

Got my last calliper from Euro car parts as Andy suggests. They give you some money back when you return the original one as well. Think mine worked out at about £55 in the end.

 

[Disca]

Just so happens ECP have a 30% off flash sale this weekend.
So I should just need the Pagid caliper and it will come with everything I'll need? (Complete novice with car mechanics )

 

[andyglym]

Just so happens ECP have a 30% off flash sale this weekend.
So I should just need the Pagid caliper and it will come with everything I'll need? (Complete novice with car mechanics )

The caliper comes complete, however, check your pads to see if they are on the cusp. Change both sides and your garage will be able to inform your if the disc has been warped or not. If lucky you'll just need the caliper. For a mechanic with a ramp it's a 20 minute deal I would suspect to change one caliper. 4 bolts, a metal spring/clasp thingy and the brake hose, reassemble and bleed the brakes. Very basic tools if DIY.

 

[Disca]

A friend suggested taking the existing one off first, refitting the pads, regreasing the pins and checking the pistons move prior to ordering a new one? Worth a shot or is it well known enough it'll need a new one

 

[andyglym]

A friend suggested taking the existing one off first, refitting the pads, regreasing the pins and checking the pistons move prior to ordering a new one? Worth a shot or is it well known enough it'll need a new one

If you're going down that road I'd suggest you'd need to change the seals on the piston. Again it's not a difficult job for a mechanic but for piece of mind I'd go down the new caliper route. These cars are getting on a bit.

 

[Disca]

Ordered a new calliper in the end as ECP sale made it worthwhile.

Will give BMW a call tomorrow to check if I need anything else to replace it

How come the rear ones cost twice as much when I thought the rears are less powerful

 

[Disca]

Changed the calliper yesterday.
Felt a lot better on the drive home so hopefully over the next few days I will see no more of it and the issue is fixed

 

[andyglym]

Changed the calliper yesterday.
Felt a lot better on the drive home so hopefully over the next few days I will see no more of it and the issue is fixed

Hopefully a result then.