Need some help on brake calipers

Crgwal

Crgwal

A2OC Donor
Scotland
Hi,

So I managed to change the pads on my front left with no problem.

I started the same on the right side got everything in place.

I am stuck on getting one of the two hex 7mm back into place. There is a little spring that it seems to screw into and it's slightly mishapened and for the love of me cannot get it to screw back in.

What is this spring called and I need a new one!

Many thanks,
C
 
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It's like a caliper return spring I think, but I'm sure it's not. It is probably what you said, it no longer will lock the hex 7 in place as it just spins loose...
 
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There are no return springs I am afraid. If the bolt is just spinning then it does indeed sound like a helicoil insert has been fitted to the casting to repair a previously damaged thread. If so then you have 2 options.. Replace the helicoil insert or replace the whole part.
 
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audifan said:
Great but if that fails the better solution is in the above video. Remember to use thread locking compound on the helicoil.
Click to expand...
This engineer and machinist says that it should not be necessary to use locking compound on helicoils.
The coil is wound in such a way to have its own prevailing torque when installed in a correctly tapped hole.
If the coil wont stay in, the recipient part is scrap and should be replaced.
On brakes, never go cheap.
 
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Agree but as the part already has a helicoil the locking compound is an extra backup. Already said may have to go to solid insert. ( From an engineer with 40 years experience )?
 
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Perhaps the heat generated in the caliper is enough to weaken the locking compound?

I have to say that in a safety critical area such as a brake caliper, I'd be very reluctant to go with a helicoil repair and would always go with a good used caliper. Yes, it's an extra faff to install and bleed, but it's safer and probably as time efficient and possibly cheaper also as there's plenty around.
 
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Ah, I get it now. The mount bracket is part of the hub on standard A2 front brakes (I always think of my own, which are 312mm upgrade ones).

A good used part again would solve, but would mean re-doing the geometry checks and they can be a right pain to get off without a proper spreader and a lot of brute force. Perhaps a longer bolt, a sleeve (to maintain correct spacing) and a nut on the back, if there's clearance) would be a safer solution. Or if you have a local welder, they could weld up the hole, drill it and re-tap which would be a better option again.
 
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Helicoils are a recognised repair for this. Solid insert as shown in my first video is far better than new. Reason for the locking compound is to help adhere the helicoil to the used threads that were cut for the existing pulled helicoil. Replacing the caliper will not solve this as it is indeed the carrier that has the damaged location. Other issue preventing a standard bolt / nut is these are the pins the calipers slide on.
 
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Yes, I'm aware of the sliding action of the pin and now that I've got the picture of my own calipers out of my head, I understand it's the bracket that's in need of repair or replacement.

Not withstanding, I can't agree that a solid insert is far better than new, unless I misunderstand you? As good parts are readily available now, I'd only ever use a good used part and would (and have) advised accordingly. I know there's a love of helicoil lovers out there and there's something elegant about them as an engineered solution, but in a safety critical area like this, I'd always go new (old) part over repair.
 
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