Bleeding Brakes

[kgokal]

Dealership recommended brake fluid flush and bleed, at 50k service....
Required, beneficial or DIY project, any suggestions?

Edit: 2003 VW Jetta...

 

[Killrose]

Its always a good idea. It usually comes out looking pretty bad and can be contaminated at about that mileage. But is probably a good money maker for a dealership and I'm guessing your warranty is up?

You and a knowlegable friend could accomplish the same feat in an hour for a lot less money.

 

[SVT Cobra]

brake fluid flush is easy to DIY and very beneficial.

 

[steppinthrax]

If it?s an ABS system DON?T DO. If not do it.

On another note brake fluid is very hydrophilic and water is bad in a brake system. Take off the reservoir cap. If it?s not clear flush it?.

 

[boomerang]

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

Please explain.

The word you were looking for is "hygroscopic".

To answer the OP, it's a beneficial, DIY project.

About brake fluid. Read the paragraph about brake fluid and paint.

Brake Bleeding. The Pump and Hold Method: with a helper would be the hot setup for a rookie.

 

[Jahee]

Originally posted by: boomerang

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

Please explain.

The word you were looking for is "hygroscopic".

No, its not. Hydrophillic is right. The moisture may not always be from the air.

Edit: And yea, explain please.

 

[boomerang]

Originally posted by: Jahee

Originally posted by: boomerang

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

Please explain.

The word you were looking for is "hygroscopic".[/q]

No, its not. Hydrophillic is right. The moisture may not always be from the air.

Edit: And yea, explain please.

OK, but if you want to use the "other" word, one "l" is sufficient. In this context, either one will get the point across.

 

[Jahee]

Originally posted by: boomerang

Originally posted by: Jahee

Originally posted by: boomerang

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

Please explain.

The word you were looking for is "hygroscopic".[/q]

No, its not. Hydrophillic is right. The moisture may not always be from the air.

Edit: And yea, explain please.

OK, but if you want to use the "other" word, one "l" is sufficient. In this context, either one will get the point across.

You're right there. My mistake.

 

[Killrose]

The keys to bleeding brakes @home is a helper, an 18"so piece of clear tubbing to attach to the bleeder screw and very slow and constant LIGHT pressure by the person in the vehicle and ONLY using short strokes on the pedal, NOT all the way to the floor durring the bleeding process.

A short stroke on the pedal while bleeding ensures that you don't force the master cyl piston seals into areas that may be pitted that are outside the normal sweep of the piston seals. Also a good idea to use a turkey baster to remove most all the old brake fluid from the resivoir and placing new before you start. That way you arent running probably some of the worst fluid into the system right off the bat.

 

[Zenmervolt]

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

On another note brake fluid is very hydrophilic and water is bad in a brake system. Take off the reservoir cap. If it?s not clear flush it?.

1) Brake fluid isn't "clear" even straight out of the bottle. To test it you need either some special analysis tools or a set of litmus-like strips (link). The fluids I use are amber and blue (ATE, same spec, different colors to ensure a full flush of the system).

2) It's especially critical to flush an ABS system as the water that accumulates in the brake fluid can corrode valves and pumps in the ABS system.

That said, with ABS you generally need to perform a special operation to flush the ABS pump and that's not as simple as it used to be, so if you were just recommending having a professional flush the ABS system, I can understand that.

ZV

 

[SVT Cobra]

Originally posted by: Zenmervolt

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

On another note brake fluid is very hydrophilic and water is bad in a brake system. Take off the reservoir cap. If it?s not clear flush it?.

1) Brake fluid isn't "clear" even straight out of the bottle. To test it you need either some special analysis tools or a set of litmus-like strips (link). The fluids I use are amber and blue (ATE, same spec, different colors to ensure a full flush of the system).

2) It's especially critical to flush an ABS system as the water that accumulates in the brake fluid can corrode valves and pumps in the ABS system.

That said, with ABS you generally need to perform a special operation to flush the ABS pump and that's not as simple as it used to be, so if you were just recommending having a professional flush the ABS system, I can understand that.

ZV

Quite true, I would have never learned how to do mine (usually this type of thing is a bit above my skill/tool level) but I have to change it so much when I take it to the track.

 

[steppinthrax]

Originally posted by: Zenmervolt

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

On another note brake fluid is very hydrophilic and water is bad in a brake system. Take off the reservoir cap. If it?s not clear flush it?.

1) Brake fluid isn't "clear" even straight out of the bottle. To test it you need either some special analysis tools or a set of litmus-like strips (link). The fluids I use are amber and blue (ATE, same spec, different colors to ensure a full flush of the system).

2) It's especially critical to flush an ABS system as the water that accumulates in the brake fluid can corrode valves and pumps in the ABS system.

That said, with ABS you generally need to perform a special operation to flush the ABS pump and that's not as simple as it used to be, so if you were just recommending having a professional flush the ABS system, I can understand that.

ZV

DOT 3 Brake fluid (most commonly used) is clear. However the DOT # is printed right on the to of the cap. I believe the OP would know better once he gets a new can of brake fluid.

The tool required to flush an ABS system is not obtainable by most people. Unless you have a freind who works in a shop you can borrow it from. The tool cycles the ABS pistons back and forth to get all the air out of the system. If you just blead an ABS system the standard way you will have air in your system.

 

[Zenmervolt]

Originally posted by: steppinthrax
DOT 3 Brake fluid (most commonly used) is clear. However the DOT # is printed right on the to of the cap. I believe the OP would know better once he gets a new can of brake fluid.

DOT 3/4 blue and Amber fluid.

DOT 4 fluid is 100% compatible with DOT 3 fluid.

Even standard fluid isn't clear. At best it's a very light yellow. But as I said, color is not a reliable indicator. If the color has changed, you are already in trouble. Brake fluid still looks "good" even when it needs to be replaced. It has to get really, really bad to change color. That's why you use the litmus strips I mentioned earlier.

ZV

 

[boomerang]

Originally posted by: steppinthrax
The tool required to flush an ABS system is not obtainable by most people. Unless you have a freind who works in a shop you can borrow it from. The tool cycles the ABS pistons back and forth to get all the air out of the system. If you just blead an ABS system the standard way you will have air in your system.

I'm sorry but I'm not buying that.

Why you might need the tool.

This article explains that it's not a problem of having air in the system, it's that dirty brake fluid could be left behind.

The OP doesn't want to bleed because he has air in his system, he wants to flush it and have clean fluid. Now, if he had introduced air in the system, say through a leak, then if his ABS unit is one with "hidden passages" it's entirely possible that he would not be able to remove the air.

Proper bleeding at the wheels themselves regardless of whether it's an ABS system or not, will not introduce air in the system. Before the arguments start, remember I said proper, the most important thing being to not allow the master cylinder to run dry.

 

[steppinthrax]

Originally posted by: boomerang

Originally posted by: steppinthrax
The tool required to flush an ABS system is not obtainable by most people. Unless you have a freind who works in a shop you can borrow it from. The tool cycles the ABS pistons back and forth to get all the air out of the system. If you just blead an ABS system the standard way you will have air in your system.

I'm sorry but I'm not buying that.

Why you might need the tool.

This article explains that it's not a problem of having air in the system, it's that dirty brake fluid could be left behind.

The OP doesn't want to bleed because he has air in his system, he wants to flush it and have clean fluid. Now, if he had introduced air in the system, say through a leak, then if his ABS unit is one with "hidden passages" it's entirely possible that he would not be able to remove the air.

Proper bleeding at the wheels themselves regardless of whether it's an ABS system or not, will not introduce air in the system. Before the arguments start, remember I said proper, the most important thing being to not allow the master cylinder to run dry.

I think you don?t understand some of the basic principles of hydraulics. Brake fluid is like a hydraulic fluid that has almost no compression. Air, Water, Dirt can be compressed when one steps down on the pedal. If you had air in your system it will compress more then brake fluid degrading brake performance. Also Air, Water and Dirt are not inert with brake system components. Air/water for example can cause oxidation of brake components.

An ABS system doesn?t always bleed like a non-ABS system. Sure you might get away with bleeding an ABS system like a non but it?s not a good idea. For one thing different brand cars have different ABS systems. The valves in an ABS system might be closed in certain wheels when the car is off. As you bleed the system you might find no brake fluid coming though a wheel. This happened when I was bleeding a Saturn with ABS. The valves to the rear wheels are closed when one shuts off the car. So fluid can?t travel from the master to those wheels if you were bleed or exchanging the fluid. When the car is started the valves cycle.

 

[steppinthrax]

Originally posted by: boomerang

Originally posted by: steppinthrax
The tool required to flush an ABS system is not obtainable by most people. Unless you have a freind who works in a shop you can borrow it from. The tool cycles the ABS pistons back and forth to get all the air out of the system. If you just blead an ABS system the standard way you will have air in your system.

I'm sorry but I'm not buying that.

Why you might need the tool.

This article explains that it's not a problem of having air in the system, it's that dirty brake fluid could be left behind.

The OP doesn't want to bleed because he has air in his system, he wants to flush it and have clean fluid. Now, if he had introduced air in the system, say through a leak, then if his ABS unit is one with "hidden passages" it's entirely possible that he would not be able to remove the air.

Proper bleeding at the wheels themselves regardless of whether it's an ABS system or not, will not introduce air in the system. Before the arguments start, remember I said proper, the most important thing being to not allow the master cylinder to run dry.

Also I've read that particular article a while back. I believe the person who wrote that recomended if you wanted to cycle the brake system you simply would bleed the ABS system like normal and then drive the car slamming on the brakes a couple of times thus cycling the system.

:Q

 

[steppinthrax]

Originally posted by: boomerang

Originally posted by: steppinthrax
If it?s an ABS system DON?T DO. If not do it.

Please explain.

The word you were looking for is "hygroscopic".

To answer the OP, it's a beneficial, DIY project.

About brake fluid. Read the paragraph about brake fluid and paint.

Brake Bleeding. The Pump and Hold Method: with a helper would be the hot setup for a rookie.

Hydrophilic is water loving. Brake fluid absorbs water. Hygroscopic is the ability for a substance to attract water. Both are the same but one describes the act while one describes degree of.