Brake fluid exchange procedure

[strohw]

Yea I had one in the past, but lost it at some point. I will likely buy another one anyway. Is the cap 0108/0118?

Ya.

If you happen to have a 1.5hp or larger air compressor then you can also use tools like these: https://www.amazon.com/BILITOOLS-Pn...09PYBGVSQ/ref=cm_cr_arp_d_product_top?ie=UTF8

 

[MatthewAMEL]

I'm not a huge fan of the Motive method. I have had a few caps fail or not fully seat and wind up with brake fluid all over the engine bay.

I prefer using the MityVac.

https://a.co/d/2rZxGNG

Here is a crappy video I posted a few year back using the MityVac to bleed my 1LE brakes. Method works for BW as well.

 

[Mircrowaved_Bananas]

I'm not a huge fan of the Motive method. I have had a few caps fail or not fully seat and wind up with brake fluid all over the engine bay.

I prefer using the MityVac.

https://a.co/d/2rZxGNG

Here is a crappy video I posted a few year back using the MityVac to bleed my 1LE brakes. Method works for BW as well.

Second on not a fan of the Motive. Could not get the cap to seal at all. I think this is more a fault of the design of the GM reservoir. The three tabs just don't provide enough clamping force to create enough of a seal. I just un-plugged the battery and got my dad to help me do it the old fashioned way when I flushed the system.

 

[poor-sha]

I bought one of these caps and grafted it my Motive, it's never failed me.

https://www.amazon.com/gp/product/B0037668CI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

A second thing to note is that you have to fill the reservoir really slowly or it'll back up all over the place.

 

[Bourbonp]

I'm not a huge fan of the Motive method. I have had a few caps fail or not fully seat and wind up with brake fluid all over the engine bay.

I prefer using the MityVac.

https://a.co/d/2rZxGNG

Here is a crappy video I posted a few year back using the MityVac to bleed my 1LE brakes. Method works for BW as well.

@MatthewAMEL did you have to disconnect the battery for doing the bleed with the MityVac on your BW?

 

[almazing]

@MatthewAMEL did you have to disconnect the battery for doing the bleed with the MityVac on your BW?

I think the battery needs to be disconnected so that the ABS circuit doesn’t activate if the key fob or whatever gets close.

Speaking of disconnecting the battery, is disconnecting the negative terminal enough? Or do I also need to disconnect the positive terminal?

 

[MatthewAMEL]

@MatthewAMEL did you have to disconnect the battery for doing the bleed with the MityVac on your BW?

Yes, I did. Disconnecting the negative is enough.

 

[Bourbonp]

Yes, I did. Disconnecting the negative is enough.

Is there a specific order to bleed the 4 brakes? I hear that first brake to bleed is the one further to the master cylinder module…? And while bleeding, do you unscrew the fluid tank cap or Leave it closed? Thanks again!

 

[MatthewAMEL]

Is there a specific order to bleed the 4 brakes? I hear that first brake to bleed is the one further to the master cylinder module…? And while bleeding, do you unscrew the fluid tank cap or Leave it closed? Thanks again!

farthest from master cylinder is conventional wisdom. In cars with an ABS block that isn’t located near the master, bleed from farthest/nearest to ABS block.

 

[poor-sha]

Rear, then the diagonal front, then other rear, then other front. I don’t believe it matters which rear you start with. Also, inner bleeder then outer on the caliper.

 

[Head Hunter]

1.5 bottles

Forgive my ignorance, but on the M6 5VBW, isn't the brake fluid shared with the clutch fluid? Is 1.5 bottles enough to flush both systems? Trying to figure out if I need 2 bottles or 3

 

[rubberduck]

There should be a bleeder valve on the slave cylinder. Normally one would not flush the clutch line very often.

 

[jodakid69]

How much brake fluid is necessary for a brake flush? I intend to use Castrol SRF.

I just had a local Chevy Dealer perform a complete track prep for my CT4V-BW 6MT. Their work included a brake system flush with Castrol SRF (2) quarts that I supplied. I was billed $194 for the work with my supplied fluid which ran $141 + tax and shipping.

FYI, my three local Cadillac dealers refused to do ANY work with client-supplied non AC-Delco parts.

 

[poor-sha]

There should be a bleeder valve on the slave cylinder. Normally one would not flush the clutch line very often.

First of heard of them having a bleeder valve from the factory. The FSM has a procedure to bleed the clutch by pulling a vacuum on it like this.

 

[rubberduck]

First of heard of them having a bleeder valve from the factory. The FSM has a procedure to bleed the clutch by pulling a vacuum on it like this.

Never done it on my BW, just assuming all slave cylinders had a bleeder valve. At least other vehicles I’ve worked on have them. There needs to be an opening somewhere at the slave to force fluid through the line.

 

[jbawden]

Motive sells upgraded anodized metal caps for most applications. You really need to push down firmly before trying to twist. I've done dozens of fluid changes and never have had a single issue, just efficient changes with minimal effort on my part.

I've found that pushing fluid through the system is better at removing air than trying to draw a vacuum. On my KTM's the only way to bleed to clutch is positive pressure. You'll never get the air out using negative pressure or even the old school open/close pumping.

 

[poor-sha]

Forgive my ignorance, but on the M6 5VBW, isn't the brake fluid shared with the clutch fluid? Is 1.5 bottles enough to flush both systems? Trying to figure out if I need 2 bottles or 3

I just finished flushing mine with SRF. You can do it with 1 Liter bottle, but I went ahead and put 2L through this time. If you’re going to open a second bottle you might as well use it all as it’s just going to absorb moisture once open.

Also, you have to add fluid really slowly to the master cylinder. It’s easier if you just punch two holes in the foil on the cap rather than remove it.


Put a small light behind the master cylinder so it’s easier to see the fluid level. It’s right about 250 ml from the max to the min markers on the reservoir. I like to just crack open a bleeder on the rear and drain to to min, fill it up, drain it to min, and then bleed like normal. That way you’re mostly fresh fluid in the reservoir.

Bleeder screw torque is 13 lb ft, except the front on CCB cars which are 14 lb ft. 11mm socket/wrench for the bleeder.

Finally, after you’re done use some brakleen to spray the area around the bleeder and then use the straw and cover with a rag to blow any fluid out of the bleeder. If you don’t and go to the track there’s a good chance it’ll run out of the bleeder and mess up the paint on the calipers.

 

[Head Hunter]

Great stuff man, thanks

 

[MatthewAMEL]

I just finished flushing mine with SRF. You can do it with 1 Liter bottle, but I went ahead and put 2L through this time. If you’re going to open a second bottle you might as well use it all as it’s just going to absorb moisture once open.

Also, you have to add fluid really slowly to the master cylinder. It’s easier if you just punch two holes in the foil on the cap rather than remove it.


Put a small light behind the master cylinder so it’s easier to see the fluid level. It’s right about 250 ml from the max to the min markers on the reservoir. I like to just crack open a bleeder on the rear and drain to to min, fill it up, drain it to min, and then bleed like normal. That way you’re mostly fresh fluid in the reservoir.

Bleeder screw torque is 13 lb ft, except the front on CCB cars which are 14 lb ft. 11mm socket/wrench for the bleeder.

Finally, after you’re done use some brakleen to spray the area around the bleeder and then use the straw and cover with a rag to blow any fluid out of the bleeder. If you don’t and go to the track there’s a good chance it’ll run out of the bleeder and mess up the paint on the calipers.

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On all my other cars, I used my bleeder bottle with the magnet on it. imagine my 'doh' moment when I tried to get the bottle to stick to the rotor.

 

[WaveMet-V]

So does anyone know the cap needed for a Motiv bleeder? I have Motiv at home I usually use for brake bleeding.