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Consolidated Macan Brembo upgrade thread (READ FIRST POST)

Raguvian

Autocross Champion
Location
Bay Area, CA
Car(s)
2019 GSW 4MO 6MT
Because it's messy, haha. Bleeding is easy super easy with the motive. And very little fluid lost disconnecting the line if you keep the pedal pressed with the seat and 2*4.
How does keeping the brake pedal depressed prevent extra fluid from leaking out? There is still fluid in the lines no matter if the pedal is depressed or not.
 

Cuzoe

Autocross Champion
Location
Los Angeles
How does keeping the brake pedal depressed prevent extra fluid from leaking out? There is still fluid in the lines no matter if the pedal is depressed or not.
Gotta be honest, don't know how or why it works. @emichel6888 mentioned it in his thread. I tried it when I replaced the rears, and it worked. It wasn't drip free, but I was pleasantly surprised with the lack of mess in my garage.
 

GTIfan99

Autocross Champion
Location
FL
How does keeping the brake pedal depressed prevent extra fluid from leaking out? There is still fluid in the lines no matter if the pedal is depressed or not.
Don't know, but it's true.
 

Raguvian

Autocross Champion
Location
Bay Area, CA
Car(s)
2019 GSW 4MO 6MT
Gotta be honest, don't know how or why it works. @emichel6888 mentioned it in his thread. I tried it when I replaced the rears, and it worked. It wasn't drip free, but I was pleasantly surprised with the lack of mess in my garage.
Don't know, but it's true.

I've been trying to wrap my head around it for weeks after reading @emichel6888 's thread as well.
 

Will_

Autocross Champion
Location
SF Bay Area
Car(s)
2017 GTI S DSG
That's exactly what I did. I pulled the caliper off, removed dust seals, put pads in the caliper and had wife give a little push of the pedal for me, which exposed more of the pistons, greased, pushed pistons back in, replaced boots. Then did order side the same. No way I was pulling the calipers all the way back off.
So with just a little bit of the piston sticking out you were able to remove and fully seat the new dust seal? Good to know, I wanted to change mine out if need be but didn’t want to remove/rebuild (or realistically have a shop do it) the whole caliper.
 

jmblur

Autocross Champion
Location
Massachusetts
Car(s)
2017 Golf R
Self adjusting hydraulic brakes (read: every modern auto brake system) basically have an open port to the brake fluid reservoir in the master cylinder when the pedal is all the way up. this allows fluid to expand back into the reservoir when brakes are hot (and the fluid expands) and to allow the pistons to stay extended more to allow for pad wear (which requires more fluid in the system).

As the pedal is depressed, the very first thing that happens is the piston closes this port. Only once this port is closed can the system begin building pressure - otherwise that fluid would just go back up to your reservoir. So, when you begin depressing the brake pedal, you go from an open system to a closed system. At that point, fluid won't leak out (much) because to do so air would have to enter the system somewhere else, or there would have to be some significant expansion. With the brake pedal depressed, it's like putting your finger over a straw (or a pipette, for those who remember high school chemistry) - no fluid is going to leak out.
 

Raguvian

Autocross Champion
Location
Bay Area, CA
Car(s)
2019 GSW 4MO 6MT
Self adjusting hydraulic brakes (read: every modern auto brake system) basically have an open port to the brake fluid reservoir in the master cylinder when the pedal is all the way up. this allows fluid to expand back into the reservoir when brakes are hot (and the fluid expands) and to allow the pistons to stay extended more to allow for pad wear (which requires more fluid in the system).

As the pedal is depressed, the very first thing that happens is the piston closes this port. Only once this port is closed can the system begin building pressure - otherwise that fluid would just go back up to your reservoir. So, when you begin depressing the brake pedal, you go from an open system to a closed system. At that point, fluid won't leak out (much) because to do so air would have to enter the system somewhere else, or there would have to be some significant expansion. With the brake pedal depressed, it's like putting your finger over a straw (or a pipette, for those who remember high school chemistry) - no fluid is going to leak out.

Thank you for the explanation! That makes a lot of sense.

I guess I won't be doing it for my install as I'm going to flush everything out with new RBF600 but if I ever need to work on the brakes or install RPVs I'll keep this in mind.
 

Cuzoe

Autocross Champion
Location
Los Angeles
Thank you for the explanation! That makes a lot of sense.

I guess I won't be doing it for my install as I'm going to flush everything out with new RBF600 but if I ever need to work on the brakes or install RPVs I'll keep this in mind.
Might still be worth doing, flush the old fluid out with the new, instead of having to flush the old fluid + air out. At least, that makes sense in my mind.
 

emichel6888

Go Kart Champion
Location
TX
By pulled the caliper you off you just mean unbolted from the knuckle right? Dust seals off, pads in (or a wooden block, whatever) so the pistons don't push all the way out... grease them up. Seals back on, bolt them back up? The line is plenty long enough to rest on a foam mat on the ground if you pull it off the little "keeper" on the knuckle. That means little to no brake fluid mess then, hopefully?

If so I might try to do that next weekend. I haven't ordered the part for the RPV's yet but I will this week.
I know it is a bit more work and mess, but I am very skeptical about how effective this process could be. I can't help but think it is comparable to this method for adding engine oil:


You can tell this young lady in her DIY jeans really knows what she is doing, because she is smart enough to make sure she is getting the oil evenly spread all of the engine bay. #doingitright :)


Think about it, if brake fluid (at around a 1000 PSI) is not getting past the seal, how is grease at 1 bar going to get in there and lubricate the seal? It is about as likely as the oil these ladies are pouring all over the engine getting inside the engine.

Just get a low wide bucket or plastic bin to place under the caliper, a couple cans of brake cleaner, and some shop towels, and it really isn't that big of a deal. Honestly jacking the car and taking the wheels off and on is the hardest part IMO, so if you are already doing that I say take a few more minutes and do it right, there are far worse things than a little spilled brake fluid.

The easiest way to do it is to remove the pads and use the system to push the pistons most of the way out with the brake pedal. However without a pad the pistons will push past the seal so you can end up with one piston out with a brake fluid mess and the other three still more or less recessed. So you want to put something thinner in place of the pads first, a completely worn set of pad backings would be perfect if you have them, but any bit of wood or metal about 5 mm thick will do.
Once you have the pistons most of the way out you can use a stick to depress the brake pedal and disconnect the line. Then if you have compressed air you can push the fluid in the caliper out through the line/bleeder screw (this is optional and not necessary). You don't have to completely remove the caliper to do this but you were already down to a single loose bolt so I highly recommend removing them, just drop it into your shallow wide bucket and clean it up on a bench/table.
You want to clean the seals with alcohol/paper towels so they are not covered in brake fluid before applying the grease. So just clean everything up first then grease it up really well and pop it all back together. It really doesn't add much time and effort to what you were already doing, and if you have a bucket and some cleaning supplies it is not bad at all.
 

GTIfan99

Autocross Champion
Location
FL
I know it is a bit more work and mess, but I am very skeptical about how effective this process could be. I can't help but think it is comparable to this method for adding engine oil:


You can tell this young lady in her DIY jeans really knows what she is doing, because she is smart enough to make sure she is getting the oil evenly spread all of the engine bay. #doingitright :)


Think about it, if brake fluid (at around a 1000 PSI) is not getting past the seal, how is grease at 1 bar going to get in there and lubricate the seal? It is about as likely as the oil these ladies are pouring all over the engine getting inside the engine.

Just get a low wide bucket or plastic bin to place under the caliper, a couple cans of brake cleaner, and some shop towels, and it really isn't that big of a deal. Honestly jacking the car and taking the wheels off and on is the hardest part IMO, so if you are already doing that I say take a few more minutes and do it right, there are far worse things than a little spilled brake fluid.

The easiest way to do it is to remove the pads and use the system to push the pistons most of the way out with the brake pedal. However without a pad the pistons will push past the seal so you can end up with one piston out with a brake fluid mess and the other three still more or less recessed. So you want to put something thinner in place of the pads first, a completely worn set of pad backings would be perfect if you have them, but any bit of wood or metal about 5 mm thick will do.
Once you have the pistons most of the way out you can use a stick to depress the brake pedal and disconnect the line. Then if you have compressed air you can push the fluid in the caliper out through the line/bleeder screw (this is optional and not necessary). You don't have to completely remove the caliper to do this but you were already down to a single loose bolt so I highly recommend removing them, just drop it into your shallow wide bucket and clean it up on a bench/table.
You want to clean the seals with alcohol/paper towels so they are not covered in brake fluid before applying the grease. So just clean everything up first then grease it up really well and pop it all back together. It really doesn't add much time and effort to what you were already doing, and if you have a bucket and some cleaning supplies it is not bad at all.
The grease gets on the pistons, which get pushed back into the seals, so probably not the same as greasing seals and pistons, but it isn't dumping oil on the engine. It did make a difference for me.
 

emichel6888

Go Kart Champion
Location
TX
The grease gets on the pistons, which get pushed back into the seals, so probably not the same as greasing seals and pistons, but it isn't dumping oil on the engine. It did make a difference for me.
It probably does help to some degree, and I know it is not the same, these just make me laugh so any excuse to post them... :) They are probably staged, but you just know that someone somewhere has actually done this, which is why it is so funny.
I just really think if you are going to take the time and effort to do all that, then you mine as well pull them out completely to clean/lube them properly. It really isn't that much more work/mess, and would provide better results for a longer time.
 

GTIfan99

Autocross Champion
Location
FL
It probably does help to some degree, and I know it is not the same, these just make me laugh so any excuse to post them... :) They are probably staged, but you just know that someone somewhere has actually done this, which is why it is so funny.
I just really think if you are going to take the time and effort to do all that, then you mine as well pull them out completely to clean/lube them properly. It really isn't that much more work/mess, and would provide better results for a longer time.
Totally agree, and I will do it next time I'm doing a full fluid replacement, but I wanted to see if it was worth doing.
 

spaparizos

Ready to race!
Location
Mountain View, CA
Car(s)
'17 GTI Sport
I haven't received it yet as they are made to order. And just to make sure you know that I did get it for the OEM calipers.

I have a track weekend in early March and will report back.
Perhaps we need a different thread on them to not hijack the macan one then :)

I am curious on what you find out. For example, do they work well, with what tires and what rear pads. Are they street able at all, or what is the bedding needed if one has the ds2500 for the street and swaps the fronts to ds3.12 for the track.
 

scrapin240

Drag Racing Champion
Location
IzzaGolf
Car(s)
Golf
Self adjusting hydraulic brakes (read: every modern auto brake system) basically have an open port to the brake fluid reservoir in the master cylinder when the pedal is all the way up. this allows fluid to expand back into the reservoir when brakes are hot (and the fluid expands) and to allow the pistons to stay extended more to allow for pad wear (which requires more fluid in the system).

As the pedal is depressed, the very first thing that happens is the piston closes this port. Only once this port is closed can the system begin building pressure - otherwise that fluid would just go back up to your reservoir. So, when you begin depressing the brake pedal, you go from an open system to a closed system. At that point, fluid won't leak out (much) because to do so air would have to enter the system somewhere else, or there would have to be some significant expansion. With the brake pedal depressed, it's like putting your finger over a straw (or a pipette, for those who remember high school chemistry) - no fluid is going to leak out.
worked perfectly when I removed the calipers yesterday. Not a drop from the brake lines on the car.
 
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