brake fluid replacement

[carlos_knology]

I just bought a vacuum pump/bleeding kit and intend to use it to totally replace the brake fluid in my motorcycle as well as in my J30.

I had the J30 brake fluid replaced by my mechanic a few months back but the fluid just doesn't look clean enough to me.

I know how to use the vacuum pump. My question has to do with the ABS system. When I use the vacuum pump on each wheel, will any of the fluid in the ABS system be pulled by the vacuum pump?

Also, do I need to do anything in particular as it relates to the ABS system and vacuum-bleeding the fluid?

BTW - I'll take pics and post an article on my website whenever I do this.

Thanks, Carlos.

[R4v3n]

Where did you get the vacuum pump/bleeding kit at and how much was it, may I ask? I'm sure me and my friends around here would chip in to buy 1 to use it where needed instead of going somewhere to be charged with 900% interest.

[Q451990]

If the J is set up like the Q, I think all of the brake fluid flows from the master cylinder through the ABS pump. On the Q it has two bleeder valves on the ABS actuator, so you bleed the RR, LR, RR, LR, Rear ABS, then Front ABS.

Heath

[carlos_knology]

Where did you get the vacuum pump/bleeding kit at and how much was it, may I ask? I'm sure me and my friends around here would chip in to buy 1 to use it where needed instead of going somewhere to be charged with 900% interest.

Got it from http://www.bradystools.com/vacpumkitmit.html

Shipping was around $6 and it shipped FAST. It was delivered two days after I placed the order online.

Carlos

[carlos_knology]

If the J is set up like the Q, I think all of the brake fluid flows from the master cylinder through the ABS pump. On the Q it has two bleeder valves on the ABS actuator, so you bleed the RR, LR, RR, LR, Rear ABS, then Front ABS.

Heath

My ABS actuator doesn't appear to have any bleeder valves. I went in the garage and checked the actuator.

I checked the service manual for the J and page BR-4 states:

"Bleed air in the following order:

Master Cylinder, Right Rear, Left Rear, Right Front, Left Front."

What made me ask is that the manual that came with the vacuum pump mentioned "depressurizing the ABS system" and a later paragraph stated "Various Asian, European, and domestic manufacturers use bleeding procedures which require specialized equipment".

This is what made me wonder if I could just vacuum-bleed the J30 like I do my motorcycle or if I need to do anything special when dealing with the J30 and the ABS system.

Carlos

[Q451990]

Hmmm... not sure how you bleed the master cylinder. Maybe Q45Tech will have some suggestions...

Heath

[Q45tech]

If you don't have access to the $4,000 ABS test simulator to cycle the residual fluid out..........all you can do is bleed the system, drive using the ABS then rebleed a few times. Eventually you will get most exchanged.

Unlike the traction control which applies pressure to rear without master cylinder movement, the ABS releases pressure by having some place for the rear, LF, or RF pressure/volume to go.

Without the equipment, I just bleed every year NOW, [but it took dozens of times over 6 years to get the system spotless].

The visable signal is when the master cylinder fluid changes color. Is not and does not stay perfectly clear. Even amber shows the presence of water [breakdown products] via desolving seals.

You would be shocked at the number of black fluid systems we see. Yet my [60k replacement ABS] now has almost 200k and still functions. Takes about 6 months for my fluid to turn light amber.

If you ever have brake fluid fade in the mountains, you will usually not forget it. Important to find out what you leg strength is before it happens........how long can you [your leg] extert 120-150-170 pounds, is the seat position correct for you to do so.The fire wall will bend and deflect as the pressure gets this high and the master cylinder will back off, then you have to add more force ........each car is slightly different.

[Q45tech]

The factory manual states you must apply 110 pounds of pedal force to create maximum pressure.[1067 psi]......brand new no air bubbles. In a 3.3 " stroke.

[carlos_knology]

If you don't have access to the $4,000 ABS test simulator to cycle the residual fluid out..........all you can do is bleed the system, drive using the ABS then rebleed a few times. Eventually you will get most exchanged.

Q45Tech, thanks for the always-informative replies. Quick question though, when you say "drive using the ABS", do you mean to drive using the brakes as I normally do or to actually try to engage the ABS system (try to lock the tires)?

Carlos