Front caliper banjo bolt torque specs?

[jyi786]

You all definitely helped me out, can't fault you for that, totally grateful. This is just more for info; I just hope anyone who comes across this thread does it in time before they change their caliper and then royally screw something up because of the little banjo bolt!

 

[wsteele]

You all definitely helped me out, can't fault you for that. This is just more for info; I just hope anyone who comes across this thread does it in time before they change their caliper and then royally screw something up because of the little banjo bolt!

One thing that crossed my mind, what material were the crush washers? I am wondering if too soft a crush washer material could screw up the torque specs?

 

[jyi786]

One thing that crossed my mind, what material were the crush washers? I am wondering if too soft a crush washer material could screw up the torque specs?

All the crush washers I have are directly from GM. They are copper; very soft.

 

[wsteele]

All the crush washers I have are directly from GM. They are copper; very soft.

I was just wondering if the material were soft enough, it might allow the screw to bottom, taking some contact area in the threads (and strength of the fastener body) out of the torque/yield equation. Just guessing as it really is a head scratcher.

 

[jyi786]

I was just wondering if the material were soft enough, it might allow the screw to bottom, taking some contact area in the threads (and strength of the fastener body) out of the torque/yield equation. Just guessing as it really is a head scratcher.

Actually, that's what was surprising. When I took the set off, after the first banjo bolt got screwed up, I actually was able to REUSE the new crush washers after the first install attempt because they were in immaculate condition. Like they weren't even "crushed".

 

[wsteele]

Actually, that's what was surprising. When I took the set off, after the first banjo bolt got screwed up, I actually was able to REUSE the new crush washers after the first install attempt because they were in immaculate condition. Like they weren't even "crushed".

Very strange indeed. I wonder if maybe the bolts weren't the proper material, improper heat treating or maybe knock-offs?

 

[Geotrash]

Very strange indeed. I wonder if maybe the bolts weren't the proper material, improper heat treating or maybe knock-offs?

Yeah, that's my worry also. I would be hesitant to put any pressurized component in my braking system that couldn't hold up to the factory torque specs. Because if it fails, it will do so when it's under the greatest pressure load, such as under emergency braking. I'd be inclined to order a new bolt from GM and swap it out if it were my truck.

 

[jyi786]

Yeah, that's my worry also. I would be hesitant to put any pressurized component in my braking system that couldn't hold up to the factory torque specs. Because if it fails, it will do so when it's under the greatest pressure load, such as under emergency braking. I'd be inclined to order a new bolt from GM and swap it out if it were my truck.

The bolts and crush washers were straight from GM.

Banjo bolt: PN #11569669
Banjo bolt washer: PN #21012386

I hear you about the emergency braking. That's why I took it out yesterday after I was done, and gradually braked, until I was confident enough. I then took it to 70+ MPH and stomped on the brake to bring it down to zero. I did this about 7-8 times. I've never felt my truck ever stop better; it almost stops like a small car would. I actually have to be more judicious now compared to before with brake usage, because a light tap is all that's needed; pushing it too hard is enough to slow down the truck really fast (i.e. the brakes are way more responsive now).

 

[jyi786]

double post....

 

[wsteele]

The bolts and crush washers were straight from GM.

Banjo bolt: PN #11569669
Banjo bolt washer: PN #21012386

I hear you about the emergency braking. That's why I took it out yesterday after I was done, and gradually braked, until I was confident enough. I then took it to 70+ MPH and stomped on the brake to bring it down to zero. I did this about 7-8 times. I've never felt my truck ever stop better; it almost stops like a small car would. I actually have to be more judicious now compared to before with brake usage, because a light tap is all that's needed; pushing it too hard is enough to slow down the truck really fast (i.e. the brakes are way more responsive now).

I just wonder what is the problem with the banjo bolts not holding up to the torque spec and even not holding up to the crush washers not crushing at all. To me, if I am a tech at a GM dealership, I am calling the mothership right away and telling them "Houston we have a problem". I mean, I know OE parts have issues with quality control from time to time, but a banjo bolt on a brake system not being able to be torqued to spec without yielding seems like a REALLY BIG problem.