11 replies to this topic

[antcole]

Hello folks,

Just overhauling the 8.4 calipers and cant find the torque for the bolts which hold the two halves together.

Looked through the brilliant torque ref sheet posted here but its not listed, only shows the caliper to hub torque.

Many thanks in advance

[jime17]

It's not allowedto split them. I did before I knew this three months ago and now I'm waiting for them to fail.


Seriously though. make sure you change the o ring and clean the mating surfaces. I don't know the torque I'm afraid. I just did mine FT. loctite I'd say would be advisable too.

I believe it not to be good practice to split them as it's hard to get them to seal. I did one of mine as I couldn't get a seized piston out any other way and it's been ok so far touch wood but theres lots of really experienced people on here warning against it so you'd be silly not to consider what they say.

[TopCatCustom]

They're made in 2 halves, and callipers are often overhauled so I don't know why it wouldn't be allowed to split them. Use the correct high tensile bolts and the correct torque and I don't see why it should be any different to a new calliper.

[jime17]

They're made in 2 halves, and callipers are often overhauled so I don't know why it wouldn't be allowed to split them. Use the correct high tensile bolts and the correct torque and I don't see why it should be any different to a new calliper.

That was my initial thought but as I say there are plenty of posts warning against doing it. I've not had enough experience overhauling callipers to argue against some of the people here.

I did one of mine and maybe it was luck that it sealed ok. (using a new o ring). I just hope it doesn't come back to bite me in the bum.

Maybe I'm just a worrier lol

[Cooperman]

I always split the calliper into 2 parts when doing a re-build. You do need a new O-ring and the correct torque setting is 45 lb.ft with Loctite applied. The faces must be clean, as must everything when re-building brakes.
It's an 'urban myth' that the two halves should not be split.

[jime17]

I always split the calliper into 2 parts when doing a re-build. You do need a new O-ring and the correct torque setting is 45 lb.ft with Loctite applied. The faces must be clean, as must everything when re-building brakes.
It's an 'urban myth' that the two halves should not be split.

That's good enough for me then.

I'm guessing that failure of a reassembled caliper would either mean the bolts would work loose or fracture, or the seal would fail.


if the two halves have sealed ok in the first place and the system is maintaining pedal pressure is it fair to assume that the seal is a good one and likely to remain so for the life of the new o ring?

[antcole]

I always split the calliper into 2 parts when doing a re-build. You do need a new O-ring and the correct torque setting is 45 lb.ft with Loctite applied. The faces must be clean, as must everything when re-building brakes.
It's an 'urban myth' that the two halves should not be split.

Thanks Cooperman, really appreciated mate.

[conrod]

I'm liking Cooperman's input. Like Antcole I scoured the books and net but no torque setting was found. My thought was to contact Lockheed or Girling. Cooperman can you tell us where you got your setting from? It needs to be added to torque settings in our manuals and restoration books. Cheers Kev.

[nicklouse]

Some more reading with slightly different numbers.

http://www.theminifo...-reconditioning

[Spider]

Some more reading with slightly different numbers.

http://www.theminifo...-reconditioning

 

In that link, I posted a torque figure of 60 ft / lb. That is correct for genuine 8.4" AP Calipers. The non-genuine types seem to take an M10 Metric Bolt. I have no data on those.

[g0myw]

I'm in the "split them" camp. 
Have done several (motorbike) calipers and have never had any problems.
As with anything brakes, keep it clean and you'll be ok.
If you're not happy, thethen don't do it.

 

[MaximMini]

Hi Everyone,

 

When selecting the thread lock, you should consider that brake fluid in worth case scenario (DOT 3 with maximum water content of 3.5%) will maintain a boiling temperature of minimum 130 °C. I therefore went for Loctite 270, which is high strength and rated for up to 180 °C.

 

Cheers