Brake Disc Size

[T5R+]

Suspect need some new front pads.

The car parts sites think that they could be 295mm or 322mm or 344mm.

Is there any easy way to ascertain (without taking off the wheel ).

Thx.

 

[alecmascot]

Use one of the online EPC's with your VIN to check what you have. As long as a previous owner has not modded it.

 

[KennyN]

Measure them , depending on how much room you have between the wheel spokes.

12" steel rulers x 2
Magnets x 2 or assistant x 1
Tape rule.

Using the magnets stick a ruler to the disc and the other 180 degrees from it and use the tape rule to measure between them.

Simples , did the above with the Porker as some discs are 370 / 375 / 380mm so some room for error when measuring and wanted to get it right.

K

 

[T5R+]

Came in at 342mm.

(That is only 3 days worth of dust on the rims!)

 

[chic0821]

12" steel rulers x 2
Magnets x 2 or assistant x 1
Tape rule.

Or, get a bit of string & run it round the outside diameter of the disc & measure the length
Formula is 3.142 x D = Circumference (length of string

For 295 size the string would be approx 927mm
For 322 size of string would be approx 1012mm
For 344 size of string would be approx 1081mm

 

[T5R+]

Or, get a bit of string & run it round the outside diameter of the disc & measure the length

You just know that I am going to undertake this also - once the downpour stops. .........even the fiddly bit around the caliper.

 

[Petrol Pete]

May I ask why taking the wheel off is a problem ? even with the wheel off accurate measurement can be a bit tricky.

 

[Muckypaps]

You've spent longer making this thread and reading the replies than it takes to remove the wheel.

 

[W1ghty]

You've spent longer making this thread and reading the replies than it takes to remove the wheel.

But think of all the alternative ways he has learnt buddy

 

[geoffus]

Came in at 342mm.

(That is only 3 days worth of dust on the rims!)

Is that a crack in your tyre sidewall ?

 

[zipdip]

Wow does look like it,this job just got a bit more expensive

 

[optimusprime]

TSR geoffus just saved your life .. Do you have a vin number i will do it for you to save you time asking about and measuring up like that is a bit hit and miss ..

 

[T5R+]

Is that a crack in your tyre sidewall ?

It is. Actually need 2x front tyres. About to buy a pair...........................

Also, a "new" n/s/f alloy.......................

Chap in builders van decided he wanted to be in L3 of the motorway as I was passing. He also managed to scuff the bumper and wing.

 

[optimusprime]

T5R Not a bit of luck ,, it all looks expensive.. a new wheel along with tyre and discs ...See if alloy wheel repair shop can do it first

 

[T5R+]

T5R Not a bit of luck ,, it all looks expensive.. a new wheel along with tyre and discs ...See if alloy wheel repair shop can do it first

Appreciated.
"My" wheel man can infill weld, flat and powder coat.
Mercedes cannot supply this front rim any longer - rear still orderable.
"I"can source at £700ish per rim whilst insurance approved garage struggling.

We all know how this goes.........insurance company will want to repair, customer will request a new rim, whatever happens the "new" rim colour will not match the other 3.

It is so amusing watching the lack of coordination between broker, insurer, approved garage, hire car company and me. At some stage I will get bored and may offer to manage it myself.

 

[Funkyboy]

Get the autodoc app and use the live chat function. You will need the VIN number

 

[T5R+]

Whilst waiting, decided to change the discs/pads. (Pins were a nightmare - liberally greased now with new parts).

Sourced from MB.

 

[Duffy3074]

Can’t help but notice the old/knackered tyre is on the repaired wheel

 

[optimusprime]

TSR i dont know how you have managed to get 17 posts without any profile ???? i did not know what car you were talkig about .