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Flushing Brake Fluid, Replacing Rotors, brake lines...

4K views 15 replies 6 participants last post by  dslboomer 
#1 ·
Okay so I need to replace my rotors and decided to do a weekend job of it. Since I am replacing the rotors, I decided to go all out and replace pads, brake lines with new stainless steel ones, and I thought it would be cool to paint my calipers too, since they are pretty rusty. I've been looking at several DIY's on here about painting the calipers and replacing the brake lines and feel pretty confident that it's not a difficult task. My main concern is the brake fluid. My calipers are pretty rusty, so I am planning on given them a good cleaning and soaking them overnight with evapo-rust to get them optimally clean and ready to paint. I had planned on letting all the brake fluid drain and replacing it with new one, but after reading several threads on bleeding brakes, I am starting to see that it would not be a good idea to let all the fluid drain. Any advice on how to best tackle this small project. I don't have a pressurized bleeder, which I seen used on some of the DIY's. I guess what I'm asking is how should I flush my brake fluid when I am going to need to keep my brake calipers off my car for atleast one day? Any advice? Thanks.
 
#4 ·
Nope. No issues. Brakes working perfectly and actually feel better.

When I had the issue, warning lights, DSC and other lights showed up, but after fixing the issue they all went away.

By no means am I a mechanic and not anywhere close, but with the help of the DIY's in the forum and googling I was able to fix it myself and save alot of $$$
 
#5 ·
Cool, well I'm like you. I'm not a mechanic either, but I do like to tinker with stuff and I have found the DIY's on here very helpful. Thanks for letting me your experience with this issue. I'll let the fluid drain and just bleed it properly. I did purchase a bleeder from amazon, not a pressurized one though, but according to the reviews it does the job.
 
#6 · (Edited)
Some of those brake bleeder kits are labels as "1 man brake bleeder kits" but I still had someone help out and press the brakes while I released the screw to observe the fluid being released to make sure I got rid of all the air from the system.

It's very satisfying experience doing it on your own and learning how to maintain your E46

Someone posted a tip to use a different colored brake fluid for the new brake fluid so that you could tell the system has been replenished with the new fluid by the color of the brake fluid being released when purging the old fluid and air out (if that made sense)
 
#7 ·
Don't soak calipers in anything. Just wire brush and paint. Caliper paint is made for high temps, and to stick well to rust. It typically doesn't last very long, but given the environment it's in that's not really a surprise.

to replace the lines, use a piece of wood wedged between the seat to depress the brake pedal slightly. Then unhook the lines. Use flare wrenches, not regular ones!

To bleed the brakes, you shouldn't need special equipment or anything. Fill reservoir, crack the bleeder, pump the pedal. Make sure you don't suck air at the master cylinder, because you'll have to do the whole process over.
 
#10 ·
I am currently doing almost the exact same thing to my car but in addition to the lines, rotors, pads, and painting, I am rebuilding all calipers. I had a front inner pad that had drastically more wear and discovered a slightly seized piston. The calipers are very rusty and I noticed a small tear in the rubber boot around the piston so I figured to just do them all.

Good to know about the wrenches. I have purchased a Mityvac MV8000 to help with bleeding process. I have a question though. If I am planning on having the brakes off of the car for a day or two to complete the rebuild, should I be fitting a rubber plug to the brake system to keep it isolated from the elements or even to keep some fluid in the system until I am ready to reassemble and bleed? I have read that the system should never be dry.
 
#11 · (Edited)
Do not drain the brake fluid all the way down. I say dznuts007 is exception for not having sponge brake. Even pressure bleeder will not completely eliminate trapped air in the abs system, and you will not be happy when that happens. It is a good thing you did research before you do the work. I had a first hand experience.

Clamp the brake hoses using these locking pliers until you are ready to re-install your calipers and new brake lines while making sure enough brake fluid is in the reservoir.
http://www.harborfreight.com/6-inch-needle-nose-locking-pliers-39715.html

While you are at it, why not rebuild the calipers too?
 
#13 ·
Thanks for the info, I did see some other threads where they advised not to let all the brake fluid drain. This has been my biggest concern, how to keep it from draining. I thought maybe keeping the old brake lines on and positioned so they don't hang, maybe that way they won't leak out all the fluid. I would use needle nose pliers, but I don't have 4 for all the lines :(, so I would only have one brake line clamped. I thought about rebuilding the calipers too, but already this project is costing more than I expected. While searching ECS for rotors and pads, I saw something about the DISA valve and decided to check mine too, and sure it enough it was not functioning at all. There went another 200. I might still decide to rebuild the calipers though, haven't decided, any advice on how to best tackle this rebuild? Once again thanks for all the info
 
#16 · (Edited)
1. Fold the hoses tight and tape them. Or cut the hose and plug with a golf tee. Have not tried them myself though.
2. I recommend to use this 3M Scotch-Brite stripping disc to clean the caliper. It works better than wire brush type.
http://www.autobodytoolmart.com/3m-scotch-brite-roloc-clean-strip-xt-disc-07470-p-13940.aspx
3. Engine paint is more durable than caliper paint. My favorite is the understated cast iron color over primer.
http://www.amazon.com/VHT-Temperature-Engine-Paint-Aerosol/dp/B005HQ41K2/ref=sr_1_cc_3?s=aps&ie=UTF8&qid=1363484262&sr=1-3-catcorr&keywords=cast+iron+engine+paint
 
#14 ·
Best, yes...but it will work fine with just a elbow grease, a wire brush, and brake cleaner. Soaking them is a bad idea though, you have rubber seals you can compromise. Sandblasting is OK for the carriers as long as you don't aim directly at the rubber guide pin boot. I wouldn't do it to the actual caliper because, once again, you're running the risk of compromising the piston seal.

The best way to rebuild the calipers is to buy the remanufactured ones (search). This also gives the advantage of a perfectly clean surface to paint with no worries about fluid draining out.
 
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