Brake Flush/Bleed suggestions

RobVoy126

Original poster
Member
Dec 7, 2011
9
Having just replaced rotors and pads, front and rear, I decided it might be a good idea to drain the old fluid. At 145,000 miles the fluid is extremely dark. I used an Actron vacuum pump without much success. It seems to only drain the caliper and there is a lot of air like its not sealing at the bleeder. Any suggestions?
 

Chickenhawk

Member
Dec 6, 2011
782
Vacuum bleeders can sometimes take in air past the bleeder screw threads. This is why I prefer pressure bleeders.

I use the Motive Products Power Bleeder and it works great. Being lazy and not wanting to clean brake fluid out of the pressure bleeder, I simply use it to pressure the master cylinder and I bleed one brake at a time, topping up the master cylinder in between each wheel.
 

Mark20

Member
Dec 6, 2011
1,630
I picked up a Lisle one man bleeder kit and just used it on the Envoy to flush its brakes. You can get about 15 - 20 pumps of the brake pedel before you have to empty it. Just start with a little fluid in it to keep the tube in the cup submerged. Took about 1.5 hours to do all four and had no problems. First sucked as much fluid as possible out of the master cylinder, refilled and went to work. Right rear took a while to flow clear but that should be the longest run. Man was that stuff BLACK!

I had previously tried to use this with a vacuum pump but the Lisle collection cup doesn't seal airtight.

The idea of using the Motive Power bleeder to pressurize the system gives me an idea. Anybody ever add a schrader to a spare master cylinder cap and just use - say - a bicycle pump?
 

RobVoy126

Original poster
Member
Dec 7, 2011
9
Thanks for your replies. Eliminated the vacuum pump, put an inverted loop in the tube coming from the bleeder and dropped the vacuum tube into an empty ant-freeze jug. Pumped pedal until fluid looked clear. Went through 2 quarts doing the job. Was looking at a phoenix system V12 pump that pushes brake fluid from the wheel cylinders to the master. Anyone ever tried this?
 

Mark20

Member
Dec 6, 2011
1,630
I've heard concern about letting gunk go the other way and into the ABS system.
 

Mooseman

Moderator
Dec 4, 2011
25,605
Ottawa, ON
Although the "pushing fluid/gunk back into the ABS" thing is a myth, I wouldn't do it. I just suck out all the old fluid from the master, refill it and bleed the brakes the old fashioned way until it is clear. Those speedbleeders do look interesting but when the thread sealer is worn, it will let air back in when you let off the pedal.
 

Mark20

Member
Dec 6, 2011
1,630
The master cylinder bottom is kind of U shaped so I could not get any of the old stuff out of that section (front) when I used the turkey baster. That stuff had to eventually flow through the system.

Sent from my Android using Tapatalk.
 

70Nova SS

Member
Dec 6, 2011
15
If you have the money Motive Products makes the job alot easier and the wife or buddy won't whine about their leg being tired. The reason the fluid in the reservoir is dark is because of the brakes heat cycles and age so the "dark fluid" is also already in the lines and calipers so pushing the old brake fluid to the calipers is a non issue. The auto parts stores normally sell brake fluid test strips to help you find out just how far gone your fluid is. I don't miss the old one, two, three and hold routine...:thumbsup:

http://www.youtube.com/watch?v=d0h5bMoW-aw

http://www.motiveproducts.com/
 

gelato

Member
Apr 22, 2012
4
i second the vote for the motive power brake bleeder kit. i just fitted new rotors/pads/calipers on the front end and the bleeder makes it a one person job, no more pumping the brake pedal and fiddling the bleeder with 2 people (ahh the good ole days).
just be sure to get the correct master cylinder cap adapter kit, gm in this case, as they also make various caps for other makes/models.
the kit requires you to purchase a larger jug of brake fluid, as the tank capacity is huge. so no more of those small pint sized bottles, get the quart jumbo size. more fluid ensures that the siphon tube inside the tank stays submerged during the bleeding process. you don't want to open the tank up to refill it in the middle of a bleeding cycle.
 

JCJARHEAD

Member
Dec 7, 2011
128
I bought this device after reading some of the posts here. WELL WORTH IT...< $60 delivered! Makes the process crazy simple. Take the tires off....find the nice rubber cap on the caliper...remove it....use your 10mm box end and some plastic tubing.....you will be done in 30 minutes tops! I simply drained into an empty soda bottle.

I also used the Valvoline BF available at Walmart. thanks to all for pointing out this helpful device. No air in the system at all....a true one person job now.:smile:
 

meerschm

Member
Aug 26, 2012
1,079
free advice. wet the seal at the top of the resevoir cap and make sure to leak check the seal prior to putting brake fluid in the motive.

(pressurized leaking brake fluid will mess up the fine paint job inside your engine compartment and make a mess of your driveway.) don't ask me how I know.

:redface:
 

JCJARHEAD

Member
Dec 7, 2011
128
meerschm said:
free advice. wet the seal at the top of the resevoir cap and make sure to leak check the seal prior to putting brake fluid in the motive.

(pressurized leaking brake fluid will mess up the fine paint job inside your engine compartment and make a mess of your driveway.) don't ask me how I know.

Seriously.....I think this was one of the easier procedures to do....anyone on the fence about doing this.....DONT BE......First time brake bleeder here. Watch the videos a couple of times...take meerschm's good advice and do it.

Does it make me a bad guy if I talk a little junk around the neighborhood about how I just bleed my brakes to sound like I actually have a mechanical clue?:undecided:

When in reality I don't but I am a "paint by the numbers" fool thanks to GMT Nation?:wootwoot:
 

Chickenhawk

Member
Dec 6, 2011
782
And one of the best pieces of advice I read was that you didn't even need to fill the jar with fluid. As long as you keep topping up the master cylinder, you can use it just to provide the pressure. Clean up becomes seconds instead of an hour.
 

CaptainXL

Member
Dec 4, 2011
2,445
Chickenhawk said:
And one of the best pieces of advice I read was that you didn't even need to fill the jar with fluid. As long as you keep topping up the master cylinder, you can use it just to provide the pressure. Clean up becomes seconds instead of an hour.

That's true.
The caliper itself acts as a air trap in that it will not allow air to be sucked back into the lines. Since the bleed port on the calipers is at the top and air follows the line all the way to the caliper. All you need to do is fill up the reservoir and keep it full while someone slowly presses the brake pedal.

It only takes 5 or so ounces of fluid to clear the line and caliper of air. Not a lot at all.

Took me 10 minutes to bleed both front brakes with an empty reservoir. A clear plastic tube and a clear pop bottle helps keep the mess under control.
 

Chickenhawk

Member
Dec 6, 2011
782
That's true. I was overly cautious with my Motive Power Bleeder. I used it dry to provide the pressure (so it becomes a simple one-person operation) and topped up the master cylinder for each wheel. I could have done two wheels on one pressurization before topping but I didn't want to take the slightest chance of draining the master cylinder.

The Motive Power Bleeder works great, and using it dry means no cleanup is needed. Plus, I always get a bit nervous with suction bleeders because I always feel that sucking fluid into the lines can also suck debris in past the bleed screw threads, no matter how remote that possibility might be. Pushing the fluid through the lines from the master cylinder end just seems better to me.
 

Mooseman

Moderator
Dec 4, 2011
25,605
Ottawa, ON
Looks like it would work very well but looking at bleeder , it says this about the GM caps:

Yes its true. You can use a late model GM master cylinder cap (Help! p/n 42035). You have to take 5 seconds to modify it but it works fine after that. What you will find when you open the package is that the GM piece has a little groove cut in the underside of it to relieve pressure!?! I don't know what the hell that's about, but take some black (or whatever) RTV and using a scrap of the original packaging, smear the groove full of RTV and let it cure for a bit.

So it seems that there is some sort of pressure relief built in to our caps that needs to be modified.
 

Tofer76

Member
Dec 8, 2011
148
figured I would pick up a master cyl. cap at the salvage yard for each of my cars. and any others that my friends have too . I could rig up the caps to make a kit for other makes
 

tblazerdude

Member
Dec 4, 2011
321
Just bought a one man bleeder hose. Will try it and see how it works, it cost $5.87. I will still do one or two primes with the wife on the pedal after I see clear fluid.

Any brake fluid upgrade suggestions?

I have a Qt of prestone dot 3 I plan to use otherwise.
 

meerschm

Member
Aug 26, 2012
1,079
I like a DOT 4 fluid, a little higher temp, and my other cars use DOT4.

but you should be fine, as long as the quart is unopened. if you want to get fancy, you can get colored fluid, which makes it a snap to see when you are done flushing, if you start to do regular flushes. (you can alternate between blue and clear or gold) for a first flush after many years, you will not need this.

it is good to flush out the system, you will be amazed at how gunky the old fluid gets.

a little research does reveal that the DOT 4 has a higher viscosity, and may age differently than DOT3. DOT 3 was specified for the 2004.
 

jimmyjam

Member
Nov 18, 2011
1,634
Chickenhawk said:
That's true. I was overly cautious with my Motive Power Bleeder. I used it dry to provide the pressure (so it becomes a simple one-person operation) and topped up the master cylinder for each wheel. I could have done two wheels on one pressurization before topping but I didn't want to take the slightest chance of draining the master cylinder.

The Motive Power Bleeder works great, and using it dry means no cleanup is needed. Plus, I always get a bit nervous with suction bleeders because I always feel that sucking fluid into the lines can also suck debris in past the bleed screw threads, no matter how remote that possibility might be. Pushing the fluid through the lines from the master cylinder end just seems better to me.

Feel like this needs to be quoted and reiterated, use the bleeder dry and keep your eye on the MC fluid level. A little more work, but a lot less work than having to clean brake fluid off of EVERYTHING

Tofer76 said:
couldn't you use a garden pump sprayer in the same fashion with a valve added to a xtra cap??
Mooseman said:
Looks like it would work very well but looking at bleeder , it says this about the GM caps:
So it seems that there is some sort of pressure relief built in to our caps that needs to be modified.
Yeah, i've tried it and have been less than successful. that GD pressure relief channel is a PITA to get to seal and just in general the cap doesn't torque down hard enough to hold 10PSI worth of pressure
 

meerschm

Member
Aug 26, 2012
1,079
I did the flush with my motive bleader over the weekend. adapted had two rubber cap liners, had to use the thicker one, and wet the surface a bit.

after a pressure check at 12 psi while I jacked up and remove the wheel, I filled with Brake fliud and no trouble with leaks.

:wootwoot:
 

tailor

Member
May 12, 2013
13
Did my brakes with the motive bleeder, just brilliant, like taking candy from a baby.....without the noise!
 

strat81

Member
Dec 29, 2011
399
I flushed my brake lines last week. Used a Mity-Vac knock-off and filled with Valvoline Synthetic (!) DOT 3 & 4 Fluid. Don't be deceived by "synthetic" on the fluid label as the glycols used in brake fluid are all synthetic. I went through just a bit under a quart of fluid. Initial feel after the change was unimpressive, but about a half-dozen panic stops on gravel worked the ABS and firmed the pedal up a bit. It's still a mediocre feeling pedal, but better than it was.

When bleeding the front passenger line, a large glob of black stuff was pulled through, no idea what it was. :eek:

Pads still had plenty of material on them. I have no idea when/if they were replaced. I've had the vehicle for the past 32k miles and I've never done any brake work to it.
 

retiredcopper

Member
Nov 16, 2013
59
Hola all ,

07,LS w/stabilitrak. Was told that because of the stabilitrak system,I should have the vehicle running when I bleed the brakes,which i have yet to do......Is this a method to the madness or was my friend blowing smoke up my hiney?
 

Mooseman

Moderator
Dec 4, 2011
25,605
Ottawa, ON
The Stabilitrak is just an extension of the ABS system, applying the brakes when it detects a skid using the ABS and cutting the throttle.

Depending on the reason for the flush/bleed, it can be done just like all other flushes. If there was air in the system, then you will have to get it done by a dealer as they will need to cycle the ABS to clear all the valves in the ABS module. If it's just a flush where there was no air suspected, then you can do it yourself the old fashioned way.
 

jimmyjam

Member
Nov 18, 2011
1,634
I've had all 4 calipers off for powdercoating and all fluid drained for a week. used my Motive power bleeder when I re-installed and have had no issues, never needed an ABS cycle.. YMMV
 

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