Clean the brake master cylinder

[Lex]

So what you're saying is, even if you remove the reservoir, there is no need to bleed the brakes.

I was asking where he said "no need to bleed the brakes"

 

[vc commodore]

I was asking where he said "no need to bleed the brakes"

It is insinuated that removing the reservoir, air can't get into the ABS system, which means removing the reservior means air can't get into the braking system at all....

 

[Lex]

Not true.

The only way air can enter the abs modulator is if you operate the abs without sufficient fluid available. Otherwise, it is completely sealed from the normal braking circuit by valves.

You can flush the system in your driveway to bleed fluid or flush out air in the normal circuit. No need for a scan tool.

However, I agree with the earlier comment that people with little brake system knowledge should not attempt any brake repair on their own.

^^Here is what he said.
Now you said "no need to bleed the brakes" He obviously didn't say that.

 

[Skylarking]

The braking system in modern cars, especially the ABS modulator/accumulator, is a complex bit of kit which the following simplified description explain somewhat.

The following tear down is also interesting.

So if one doesn’t fully comprehend the above and how the hydraulic circuits within are routed (as well as how air entrapment can occur, how air even gets into the system) it probably ain’t a great idea to be faffing around with it. Best get the system correctly bled at a dealer or brake specialist.

Sadly the above isn’t really clear on the hydraulic pathways within the ABS system used in our VF’s… Neither is the workshop manual PDF…

Speaking of which, the workshop manual explicitly state the following within the process for hydraulic brake system bleeding (manual):

Note: If it is determined that air was induced into the system upstream of the hydraulic modulator assembly prior to servicing, the Antilock Brake System Automated Bleed Procedure must be performed. Refer to Antilock Brake System Automated Bleed.​

I‘d guess the way air can get in is via the fluid level within the BMC reservoir being drained (through careless bleeding) or disconnection of a brake line upstream of abs modulator.

I’ve also read that air downstream can get into the system by being sucked in past the calliper piston seals during lengthy abs operation. How true it is who knows but normal flushing can get rid of such down stream air.

Old brakes were so much simpler. All one needed was 1/2 a brain, the correct sized ring spinner for the calliper bleed nipples and maybe a clear tube to go over the bleed nipple and into a small container with some brake fluid in it

 

[vc commodore]

^^Here is what he said.
Now you said "no need to bleed the brakes" He obviously didn't say that.

Here's a more simple explanation. It is stated removing the reservoir, you can't get air in the ABS system, so you don't need a diagnostic interface too...It's a simple bleed procedure

So that is like saying, removing the reservoir, you don't need to bleed the brakes, because you can't get trapped air in the system...Now we all know, when you have removed the reservoir, it's not just a simple bleed procedure, regardless of it having ABS or not....

So fair enough he didn't say those exact words, but the meaning behind his post is saying exactly what I have posted....

 

[mechanic]

Here's a more simple explanation. It is stated removing the reservoir, you can't get air in the ABS system, so you don't need a diagnostic interface too...It's a simple bleed procedure

So that is like saying, removing the reservoir, you don't need to bleed the brakes, because you can't get trapped air in the system...Now we all know, when you have removed the reservoir, it's not just a simple bleed procedure, regardless of it having ABS or not....

Paragraph one is a precise interpretation of my post. I stand by this statement.

Paragraph two is you drawing a conclusion from somewhere that is incorrect. Nowhere did I say it is unnecessary to bleed the brakes.

 

[greenacc]

Use blue brake fluid instead of clear. Some brands are blue. That makes it a lot easier to see the fluid level. If it has been a few years since the fluid has been flushed it's also a good time to get a full flush done

 

[Skylarking]

Here's a more simple explanation. It is stated removing the reservoir, you can't get air in the ABS system, so you don't need a diagnostic interface too...It's a simple bleed procedure

Paragraph one is a precise interpretation of my post. I stand by this statement.

@mechanic, yeah, probably doesn't need anything more than a old fassioned bleed but the workshop manual specifically states to perform an Antilock Brake System Automated Bleed Procedure.

Me, I'd follow the manufactrurers bleed process if DIY and if i'm paying I'd want the shop to follow factory bleed proccess

 

[vc commodore]

Paragraph one is a precise interpretation of my post. I stand by this statement.

Paragraph two is you drawing a conclusion from somewhere that is incorrect. Nowhere did I say it is unnecessary to bleed the brakes.
.

Removing the reservoir introduces air into the complete system, including the ABS module....Introducing air into the ABS module requires the diagnosis tool...

 

[Fu Manchu]