Forum Replies Created
-
Replies
-
I’m a Mechanical Engineer at an automotive supplier, and a lot of what Eric said is true, but there was one major point that was left out.
The cars were built to be manufactured in a specific order of assembly in the least time possible. Because of this, you will always find things that are difficult to reach without removing something else first. Design for service is typically a low priority.
As Eric pointed out, the styling of the vehicle has an influence as well…If we had exposed screw heads, no engine covers, and non-clip together panels, we would be universally panned by the car reviewers.
The “bean counters” which in most cases are “Purchasing” people are the drivers of a lot of this. They always force us to make something more cheaply than originally intended. The OEMs also put price pressure on the suppliers in the same way. The companies are there to make money – so we have to balance price and quality. These purchasing people also know little to nothing about design.
The other thing you will see is that parts are carried over from chassis to chassis which sometimes causes unanticipated issues with repairs.
With that being said, German cars seem to be designed to not be repaired by a DIY person or independent shop.
I’m a Mechanical Engineer at an automotive supplier, and a lot of what Eric said is true, but there was one major point that was left out.
The cars were built to be manufactured in a specific order of assembly in the least time possible. Because of this, you will always find things that are difficult to reach without removing something else first. Design for service is typically a low priority.
As Eric pointed out, the styling of the vehicle has an influence as well…If we had exposed screw heads, no engine covers, and non-clip together panels, we would be universally panned by the car reviewers.
The “bean counters” which in most cases are “Purchasing” people are the drivers of a lot of this. They always force us to make something more cheaply than originally intended. The OEMs also put price pressure on the suppliers in the same way. The companies are there to make money – so we have to balance price and quality. These purchasing people also know little to nothing about design.
The other thing you will see is that parts are carried over from chassis to chassis which sometimes causes unanticipated issues with repairs.
With that being said, German cars seem to be designed to not be repaired by a DIY person or independent shop.
Eric,
I have worked extensively at an OEM caliper supplier that makes many calipers that are similar to the design you have on your Subaru.
If you knew that the caliper was bad beforehand (I would always use the C-clamp to push on the piston always so the piston-pad contact surface does not get damaged), I would remove only the banjo bolt and let it drain (use a catch pan). Then if there is clearance, I would loosen and remove the bracket bolts only and not touch the caliper.
When it comes to install the new caliper (once again if you had clearance to get at the bracket bolts with the caliper housing installed on the bracket), I would check the pin lubrication by sliding the pins out of the bracket on the bench without loosening. Once I was satisfied, I would install the shims and pads in the caliper through the rotor clearance with the caliper assembled to the bracket. This is how it is done @ the manufacturing plant when the calipers are made. You would then be able to slip it over the rotor and tighten only the bracket and banjo bolts. For someone like yourself who needs to do this as fast as possible for income, this would be the best way. It also makes it less likely that antisieze or silicone paste gets on the rotor surface.
Also, while your trick for the axle nut and lug nut worked well, I would suggest using an open end lug nut (many GM cars use these on nearly every car), and turn it around backwards so the hex is facing the rotor and tighten it hand tight. You’ll be able to get it off no problem afterwords as well.
I understand your dislike of the copper washers, but I can honestly say they do work well, but require more torque to crush them.
I would suggest everyone use torque specs on the bracket bolts unless they cannot find it. There are some cars (1st gen GM “W” cars like Luminas, Grand Prixs) that use a torque spec that is 125+ lb-ft on the bracket bolts. Its really not fun if these loosen up and really bad if the bolt falls out, which is worse on those cars with 16″ wheels and a 14″ brake package.
I’m not being critical at all, just pointing out things from my experience. This vid should still help many people.
Eric,
I have worked extensively at an OEM caliper supplier that makes many calipers that are similar to the design you have on your Subaru.
If you knew that the caliper was bad beforehand (I would always use the C-clamp to push on the piston always so the piston-pad contact surface does not get damaged), I would remove only the banjo bolt and let it drain (use a catch pan). Then if there is clearance, I would loosen and remove the bracket bolts only and not touch the caliper.
When it comes to install the new caliper (once again if you had clearance to get at the bracket bolts with the caliper housing installed on the bracket), I would check the pin lubrication by sliding the pins out of the bracket on the bench without loosening. Once I was satisfied, I would install the shims and pads in the caliper through the rotor clearance with the caliper assembled to the bracket. This is how it is done @ the manufacturing plant when the calipers are made. You would then be able to slip it over the rotor and tighten only the bracket and banjo bolts. For someone like yourself who needs to do this as fast as possible for income, this would be the best way. It also makes it less likely that antisieze or silicone paste gets on the rotor surface.
Also, while your trick for the axle nut and lug nut worked well, I would suggest using an open end lug nut (many GM cars use these on nearly every car), and turn it around backwards so the hex is facing the rotor and tighten it hand tight. You’ll be able to get it off no problem afterwords as well.
I understand your dislike of the copper washers, but I can honestly say they do work well, but require more torque to crush them.
I would suggest everyone use torque specs on the bracket bolts unless they cannot find it. There are some cars (1st gen GM “W” cars like Luminas, Grand Prixs) that use a torque spec that is 125+ lb-ft on the bracket bolts. Its really not fun if these loosen up and really bad if the bolt falls out, which is worse on those cars with 16″ wheels and a 14″ brake package.
I’m not being critical at all, just pointing out things from my experience. This vid should still help many people.