Brake Flush

[LAF]

I needed new sneakers so while I pulled the wheels I figured I would install speed bleeders and flush the brakes.

Here is the rear flush.  Notice the bag color to where the tube connects you can see where it ran clean.  This was using the GS-911 to flush the ABS block.
This image has been resized. Click this bar to view the full image.Report this image

I clean all brake parts, pads, pins, slides, anti rattle clips, and pucks every time I change tires.  Just the way I have always kept up on my pad and calipers. The pucks over time get a ring built up around them of brake dirt so I clean them off and work the pucks out by hand to clean the rings off with brake cleaner and a tooth bruch.
This image has been resized. Click this bar to view the full image.Report this image
This image has been resized. Click this bar to view the full image.Report this image

The front reservoir looked like this.
This image has been resized. Click this bar to view the full image.Report this image

And drawn out.
This image has been resized. Click this bar to view the full image.Report this image

Front with some dirt rings showing.
This image has been resized. Click this bar to view the full image.Report this image

Front ready for install.
This image has been resized. Click this bar to view the full image.Report this image

I use a copper high temp anti seize on the pin in the front caliper and I also put a thin coat on the back of the pads where they contact the pucks.

The GS-911 ABS flush works very nice.  Dirty fluid came out after my initial flush.  Speed bleeders work great and the little speed bleeder bag and hose was no muss no fuss. 

This is on a 15  so I see the need to be on the flush every 2 years. Others may not see the need for my removing the pads and cleaning the calipers and anti seizing the various slide parts and pins but just how I have always kept my bike. 

A bit of work flushing the brakes, removing and installing two wheels, cleaning all the areas that are exposed when said wheels are removed and cleaning the three calipers but well worth the effort. 

[Levisp]

Nice job. I regularly remove pads and clean the pistons in the callipers. I use a little ACF50 block grease on the pistons to prevent corrosion. Use the same grease to lube the sliding pin on the back brake. Like you use copper grease on the pad pins. I no longer use anything on the back of pads. If you have any corrosion on the calliper pistons its important to remove it before pushing the pistons back into the calliper, otherwise its possible the corrosion could damage the seals. I also avoid using anything but brake cleaner on the pistons to avoid seal damage. Keep away from WD40 apparently it can damage brake seals. Keeping the brakes clean and corrosion free is the key to hassle free brakes especially here in the UK if you ride in winter on salt covered roads. Yours look spotless.

[guest2360]

Nice job. I regularly remove pads and clean the pistons in the callipers. I use a little ACF50 block grease on the pistons to prevent corrosion. Use the same grease to lube the sliding pin on the back brake. Like you use copper grease on the pad pins. I no longer use anything on the back of pads. If you have any corrosion on the calliper pistons its important to remove it before pushing the pistons back into the calliper, otherwise its possible the corrosion could damage the seals. I also avoid using anything but brake cleaner on the pistons to avoid seal damage. Keep away from WD40 apparently it can damage brake seals. Keeping the brakes clean and corrosion free is the key to hassle free brakes especially here in the UK if you ride in winter on salt covered roads. Yours look spotless.

Are the pistons not ceramic ?

[Levisp]

Are the pistons not ceramic ?

They may have ceramic inserts but the outside shiny part of the piston looks to me to be metal. I have seen a picture of corroded pistons. Next time I have them apart I'll have a better look.

[LAF]

Are the pistons not ceramic ?

They looked metal to me just black coated, anodized,or it could have been coated.

They did clean up nice but at only 8000 miles I expected them too.  As I said I only used a toothbrush and brake cleaner. 

Regardless of composition you want to remove the built up dirt ring as the seal acts as a sweep when the piston moves in and out.  When I took them off and removed the pads I sprayed them clean over a little plastic jug. I then dropped the pads and all parts removed into that plastic to soak.  I then move the pistons to make them move past their normal range to make sure they are clean.

Ohh brain storm.  When I removed the pin in the front caliper it is the color of the pistons.  However because the pin takes a bit of pressure it had slight wear marks that were gray and going shiny in some places.  Not scientific or confirmation of the piston's composition.

That's my story and I am sticking to it.

[Our Gee]

I use shower gel and warm water to clean pistons and apply a very thin coat of red rubber grease. Seems to work well. Incidently, I think I have managed to figure out that "pucks" are caliper pistons but I'm struggling with "sneakers" so perhaps someone can translate ?. Also what does the GS-911 do in relation to a brake fluid change.

[Levisp]

I use shower gel and warm water to clean pistons and apply a very thin coat of red rubber grease. Semis to work well.

Red rubber grease is good designed for brake rubbers. I used ACF50 Block Grease because I didn't have any Red Rubber grease and was too mean to go and buy some. I emailed ACF50 to check that it was safe on brake seals. They were very helpful bottom line is Yes except on Vintage cars/bikes that would have natural rubber seals.

[Our Gee]

Just in case the addition to my last post got missed I would like to ask the question again. "What has the GS-911 got to do with a brake fluid flush". Thanks.

[Levisp]

Just in case the addition to my last post got missed I would like to ask the question again. "What has the GS-911 got to do with a brake fluid flush". Thanks.

It activates the ABS pump so pushing fluid through it. I'm guessing here but just bleeding brakes the usual way probably does not flush the ABS pump circuit. I don't have a GS9111 so maybe someone who has one can elaborate more.

[LAF]

Yes the GS-911 has a brake flush procedure under service.  If you see the first pic that is what was being done on the rear brake.  I filled the rear brake container and used that service feature until it ran clear at the nipple on the brake caliper.  You hold the pedal or handle in for 3 seconds 3 times each in the brake service in the GS-911.  It does work very nicely.

And remember when you see that color it was 2 years to the month since my bike was built.  A service not to be neglected.

[David.]

Speaking to a fellow RT owner recently, reminded me about the need to flush the brake fluid from the ABS control unit and pressure modulator, not just the F&R calipers themselves.

As above, to complete this task, a GS-911 tool or BMW diagnostic tester is required. The F&R brake fluid change is due on my 2012 RT this year (2017, every two years). As my bike is under a BMW warranty, I'll be taking it to the dealers. I was informed by the service manager that they were fighting a case on behalf of a customer with BMW warranty services over the replacement of a failed ABS unit on a bike which hadn't had the brake fluid changed.

Two years ago, it cost £58.37 to have the F&R brake fluid changed, (labour + brake fluid).

A new ABS unit costs £1,125.00!

[Lynxfixer]

Just a quick question to confirm, on a 2008 model, do you NEED a gs911 to flush the brake fluid through the abs unit or will it flush by turning on the ignition whilst doing the procedure?

[Steve F]

I use shower gel and warm water to clean pistons and apply a very thin coat of red rubber grease. Seems to work well. Incidently, I think I have managed to figure out that "pucks" are caliper pistons but I'm struggling with "sneakers" so perhaps someone can translate ?. Also what does the GS-911 do in relation to a brake fluid change.

Sneakers = Tyres...???

[David.]

This article from Motorcycle Info Pages, http://www.motorcycleinfo.co.uk/indexd5 ... geId=95176 suggests that the calliper pistons are made of nylon.

Can anyone confirm the material which the calliper pistons are made of.

[LAF]

This article from Motorcycle Info Pages, http://www.motorcycleinfo.co.uk/indexd5f2.html?fa=contentGeneric.obxaszqugbllbuna&pageId=95176 suggests that the calliper pistons are made of nylon.

Can anyone confirm the material which the calliper pistons are made of.

I am not sure what drugs the guy is taking but they are not nylon.
How in the world would nylon hold it's integrity against the heat generated by braking?
Think about how accurate that piston has to be to seal with a o-ring and think of the heat that the brake caliper generates.
Maybe I am off my rocker but I think he misspoke or took too many tokes from the bowel they were passing around while he was typing that up.