Bolt head / spline size calipers

Does anyone know what size the rear caliper retaining bolt heads are , They are a Spline ? , can't find anything to fit .

You don't say which vehicle but many such bolts are just bi-hexagonal so a 12 point normal socket/spanner does the job.

Sorry defender , it looks like a spline . So great if a 12 point standard socket wil fit

Aye Up,

Had this issue myself just recently, as bongo says a twelve point will fit but first clean as much crud off as you can then use the tightest fitting socket or spanner - I think that I found two metric that would fit a mil apart, one loosely the other with a bit of a light tap with a hammer.

13mm multipoint but it may slip if the head is a bit worn or a cheapy socket I've found. 1/2 AF multipoint fits real snug and won't slip but needs tapping on. I've got both a socket and ring spanner (britool) in the 1/2" and they work well even if the 13mm has chewed the splines a bit.

Spot on ta for that , now I know what to use hopefully without cocking it up , I do have a 3/8 drive socket but certainly not britool , And sods law just been out and got a 1/2 drive 1/2af thought it would be a bit stronger .

I'm not 100% sure but I do recall not being able to get a socket on some splined head bolts only a ring spanner.

I can get a 1/2 drive 13mm on ok , the 1/2 af, will I guess with a tap , plenty of room around the head to get a socket on, So don't need a 3/8 drive ?? , This is a defender 90 300tdi , are they different .
Likewise I've got a britool ring spanner , I'm looking good . Just hope they crack off

I can't remember what area I was working on tbh. I think it was rear caliper on a 110 Salisbury axle but might have been the front end!
I've had to change/fix alot of stuff in the last 12 months.
It's also possible that I could get a socket on after all and I just used a spanner so I could tw@t it to crack the bolt free.....dunno..but I bought the 1/2 britool for a good reason.

Britool always give you a bit of confidence