Utter Frustration, Rear Brake Caliper Carriers

[Wayne]

What are the forces on the rear brake bolts you think?

Lots, think of the torque applied against the caliper when the brakes are used.

[tweed]

What are the forces on the rear brake bolts you think?

Lots, think of the torque applied against the caliper when the brakes are used.

  I know its lots lol I was thinking more of a figure. Surely someone has worked it out. Grip will be biggest factor, due to weather condition, temperature, surface and tyre, then different weights too. 

[Bellend]

TBH does it really all matter.

If theres XYZ bolt there, instead of getting technical, put an XYZ bolt back!

They aren't expensive from TPS or a bolt shop. Get the highest tensile you require.

TBH if it failed on an emergency stop the first time and the bolts went it would still stop as it would just hit the carrier. Dangerous thing would be you wouldn't notice til the second stop!

[Bellend]

Or the caliper jamming the wheel up.

[Ess_Three]

May as well 

When I put still up we would use 20, 24mm 8.2 bolts to hold up one 3000kg I beam. I little 200kg beam would have 8, 20mm 8.2 bolts

What are the forces on the rear brake bolts you think?

I hear you...but there is a big difference between the clamping torque of a 24mm metric coarse bolt and a 10mm metric fine bolt.
The bolts are M10fine high strength for a reason.
The static load is very little - the weight of the calliper, carrier and pads...the loading under full braking is huge though.

Bottom line, in my view, is that you never knowingly fit a weaker bolt...especially on a braking system.

[Bellend]

Bottom line, in my view, is that you never knowingly fit a weaker bolt...especially on a braking system.

/thread

Get it, thread....

[ttelracs]

I got some high tensile bolts, right length, pitch and with a hex nut instead of a allen key end, so easier to work with and invested in loctite too.  Inserted the bearings front and back into the disc and added the rubber bush, all good. Then the disc would not slip onto the stub axle and on looking closely there is a lip where the bush and collapsed and worn a slight groove all the way round it.  It's scrap.
Sourced one from a chap scrapping one so not too bad or so I thought, but I couldn't remove the bolts securing the stub axle.  Was prepared to soak in WD40 and use the blowtorch to heat up when I was offered a complete rear beam unit which had been polybushed too.  With a bit of luck it should be here later this evening and then I'll attempt to fit it over the next couple of nights !
What seemed like worn rear pads has turned out to be a complete pain.

[ttelracs]

Managed to get both bolts holding the rear beam loosened and nuts of nice and easy through using a wire brush on them first and then WD 40 overnight.
Handbrake cables removed no problem and just the two 11mm nuts on the brake lines near the beam to be undone. Would have carried on through the night but it is now absolutely freezing and my hands were getting a bit stiff so stopped before I made a mistake.

[ttelracs]

Brake pipes loosened and off, tight but WD40 again prior to attempting to remove and rear beam off.  Had to grind the old bolt out of the mounting bracket to allow fitting off rear beam but sorted now.
Struggling to line up the new beam with the Powerflex bushes though, but it is bloody freezing and now gone 21:30 and may need two more jacks and one more body. Will try again in the morning but any tips on fitting by one person greatly received.
Thinking of using a couple of metal plates to help guide in the bushes as all greased up now.

[ttelracs]

The rear beam is on.   Then wiggled it around until I got one side in and used the bolt from holding the shock absorber to the beam to keep it in place.
Then did the same on the on the other side but shaved of a small amount at the top of the polybush to allow it to slide up into the mounting bracket.  All I had to do then was to lie on my back and kick the back of the beam until it lined up and then inserted the mounting bolt.  Just need to bleed the brakes and check all good.