Flush your brake fluid!!

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swat2380

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Just did a complete brake job on new to me 07 Denali with 75k. I partially drained and filled the master cylinder via turkey baster 2x's a couple months before doing the brake job. I replaced everything in the brake system including new stainless hoses, drained the calipers and was still surprised at the rust, metal, and one rear caliper had nasty grey fluid almost resembling bad gear oil.

I am lucky enough to not live in a rust prone area where lines rust out etc. I do this on all my vehicles every 2 years or so and always get a nice performance difference in braking. A fluid flush will cost anywhere from $7-$16 bucks depending on what fluid you buy.

Our rides usually spec Dot 3 but you can use 4 or 5.1 safely, I used Castrol Dot 4. For a homemade bleeder setup I used a plastic fitting from a harbor freight bleeder kit and some clear hose fed into a RC car fuel bottle with a little fluid added to prevent air getting sucked back in. I would have preferred a larger hose over the bleeder nipple but didn't have one available. Cheap, easy, usually nice performance bump and keeps you and the family safe.IMG_20171119_170828123.jpg IMG_20171119_170832097.jpg IMG_20171118_132635046.jpg IMG_20171118_132700505.jpg IMG_20171119_170828123.jpg IMG_20171119_170832097.jpg IMG_20171118_132635046.jpg IMG_20171118_132700505.jpg
 

jmm121783

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i need to do this and flush my pumpkins, tranny and transfer case
 
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swat2380

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I also did the diff's at the same time however I didn't take the cover off the rear. I removed the fill plug and used a common gear oil pump to suck it out and jacked up each side of the axle tube to get most of the fluid remaining. Normally I would open it up, inspect, clean with brake cleaner etc. but it seems to be working fine and I plan to do this again in a couple months with a new cover that has a drain plug. Took about 20 minutes and much cleaner that way.

The front was a different story some dumba$$ stripped the fill plug and its not budging. Of course I noticed this after draining the old fluid. I decided to fill it from the drain plug after screwing with it over an hour. I just added some extra fluid to account for a little spillage and it worked fine.

Remember to use RTV made for gear/synthetic oil if you take the rear cover off if you cant reuse the factory gasket. I used RedLine 75w-90 in the rear and Mobil 1 75w-90 in the front since I had it on hand.

I did the transfer case and trans a couple months back. Used Castrol Dex VI for both and some LubeGuard Platinum. I did the transfer case again after about 500 miles since it came out a little dirty and its AWD.
 
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wendal

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I've seen this service offered at different Lube shops and Firestone. Is it the same as what you're doing here? I can do pads and rotors, but opening up the brake fluid system is just something I've never wanted to attempt, as I remember my dad saying that getting air in the brake fluid system could be fatal... I'd also like to replace my hoses with braided metals. Did you do this all at once, or at different times? Are there detailed instructions out there somewhere, or should I just go and get it done and spend the extra $$? I'm fairly mechanically inclined, I've just been scared of brake fluid system. While I'm asking, has anyone ever had an issue where light braking in a turn produces a rub vibration in the brake pedal? Seems to be something like a caliper rubbing, but I cannot locate or identify it. Thanks in advance for all info!
 

Rocket Man

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I've seen this service offered at different Lube shops and Firestone. Is it the same as what you're doing here? I can do pads and rotors, but opening up the brake fluid system is just something I've never wanted to attempt, as I remember my dad saying that getting air in the brake fluid system could be fatal... I'd also like to replace my hoses with braided metals. Did you do this all at once, or at different times? Are there detailed instructions out there somewhere, or should I just go and get it done and spend the extra $$? I'm fairly mechanically inclined, I've just been scared of brake fluid system. While I'm asking, has anyone ever had an issue where light braking in a turn produces a rub vibration in the brake pedal? Seems to be something like a caliper rubbing, but I cannot locate or identify it. Thanks in advance for all info!
Instead of paying somebody to do it, get a Motiv pressure bleeder and you'll be amazed how easy it is. You fill the thing with up to 1/2 gallon of fluid, remove your master cylinder reservoir cover and replace it with the Motiv cap attached to it's tank. Then pump it up (kind of like a garden sprayer) and just go to each caliper, attach a clear hose and open the bleeders and drain the old fluid into a container. Start at passenger rear, then driver rear, passenger front and then driver front. The fluid level in your MC stays full automatically. It's about $60 but you'll always have the tool afterwards to work on brakes.
https://www.amazon.com/Motive-Produ...8&qid=1511970287&sr=8-1&keywords=motiv+for+gm
 

wendal

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Instead of paying somebody to do it, get a Motiv pressure bleeder and you'll be amazed how easy it is. You fill the thing with up to 1/2 gallon of fluid, remove your master cylinder reservoir cover and replace it with the Motiv cap attached to it's tank. Then pump it up (kind of like a garden sprayer) and just go to each caliper, attach a clear hose and open the bleeders and drain the old fluid into a container. Start at passenger rear, then driver rear, passenger front and then driver front. The fluid level in your MC stays full automatically. It's about $60 but you'll always have the tool afterwards to work on brakes.
https://www.amazon.com/Motive-Produ...8&qid=1511970287&sr=8-1&keywords=motiv+for+gm
U da man, sir. Thanks! Bought! Can I use this to install my own braided hoses? IF so, should I just replace the hoses at each wheel before bleeding that wheel?
 

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