Brake flush on "rear ABS" system with pressure bleeder: Do I need the ABS adapter?

[barrys]

Brake flush on "rear ABS" system with pressure bleeder: Do I need the ABS adapter?

Important questions in green in case you don't want to read all my praddling on and on...

I was reading up in the Helm manual on bleeding the brakes on my 1994 Ranger with rear ABS. In the other manuals (Haynes and Chiltons) they just take you through a regular old "pump the pedal" bleed procedure with no special steps for ABS. But, in the Helm manual... they say "for ABS systems" follow these million steps with the special "ABS Adapter" with the 40 pin connecter that runs the ABS pump for 60 seconds blah blah blah... or you'll end up with a spongy pedal.

Mine's not ABS all around but does have ABS. Also, I plan to use a Motive pressure bleeder. The Helm manual also has a section on using a power bleeder which does not call out any special steps for bleeding the ABS system with special tools.

I'm a noob and just guessing here... My guess is that if you do the "pump the pedal" method with the ABS, you're not actually forcing fluid through the resevoir and maybe there's some loop in the hydraulic system that goes through the ABS controller. If you instead use the power bleeder, you're always keeping everything full from the "top" of the system so no need to do anything special for ABS.

Do you (whoever "you" are) think it would be OK to use the power bleeder as instructed without doing anything special for the ABS?

Related question:
How in the hell do you drain the resevior before a flush to get that green mud colored old brake fluid out before sending the nice clean new stuff through the system?

On my VW, there's a drain attachment. I see no such thing on the truckster and you can't get a tube in through the top since they have that screen in the fill spout. Maybe that screen thing can be removed.

Perhaps I should start another thread on this second question, but maybe I'll get lucky with responses to both questions on this thread.

I do love therangerstation.com -- almost as much as I love my Ranger.

 

[Sasquatch_Ryda]

No need to do an ABS system service bleed, and to do so you will need the Rotundra tool kit for doing this (dealer only item). You can do just a normal bleed.

At the dealership I'm working at we have a brake flush machine, and it has a nozzle that you use to suck the master cylinder reservoir clean first, then it pressurized the system and fills it at the same time as you go around and do the bleed at each wheel.

 

[barrys]

Thanks for the quick reply.
> nozzle that you use to suck the master cylinder reservoir
How big is that nozzle and how do you stick it in to the resevior?
Maybe all the stuff I see in there when I look in the fill port is foam or something and maybe it compresses.

> At the dealership I'm working at
I do always love to hear that.....

 

[Sasquatch_Ryda]

Looks pretty much just like an air blowgun, but it sucks instead. Always just went through the filler.

 

[barrys]

How much fluid do you typically use for a flush? I'm guessing a half gallon should do it.

 

[Sasquatch_Ryda]

Not too sure, the machine takes a 4 liter jug of brake fluid and you just go till you get clean fluid out of all 4 bleeders.

 

[barrys]

The Motive Power Bleeder worked so well... Just like on their little youtube vid.
Love that thing...

Also, draining the resevior was interesting so I thought I'd share...

The thing that I thought was the filter in the fill hole was actually the float for the fluid level sensor. This thing did not pull out -- tried for a while with screwdrivers, dental picks, etc.

There were two teenie weenie little tabs in the fill tube that hold it in. They were about 1/16" sqaure. I imagine in the factory, you would just push the float in there and the tabs would let it pass with pushing pressure. But, since I could not pull with that much pressure, I cut them off very very carefully and even managed to keep the little cutoffs from falling into the resevior since there was brake fluid on my utility knife.

With that, the float came right out and I was able to get my drain tube in there. I was not able to suck out all the old fluid, but the flush went fine with clean clear fluid coming out of all 4 brakes.

Perhaps someone with a lot more experience than me (which would be like, well, everyone) can respond with some alternatives to get that float out. My guess is I'm not the first one to have cut those little tabs. And, based on the way the float sensor works, if a repair tech just discards the float, the customer will never ever know until their brakes get all spongy.

 

[HRTKD]

Old thread, but I would like to add my $.02.

I use the Speedi-bleed tool that pressurizes the brakes from the reservoir. I first use a medical syringe to suck out as much old fluid as possible. I attach about a 2" length of drinking straw to the tip of the syringe so I can get the tip as far in as possible. I looked at trying to get the sensor float out so I could get all (or almost all) of the fluid out. But nothing worked so I gave up. What you could do is open one of the bleeder screws at the wheel and then slowly press the brake pedal while watching the fluid level in the reservoir. Continue pressing/pumping the brake pedal until the fluid is just barely in the outlet holes in the bottom of the reservoir. I doubt you'll be able to see that so it's more of a guess than anything. You want to get the level as low as possible but don't let the reservoir run dry or you'll introduce air to the lines. Fill the reservoir with clean fluid and then proceed to bleed the brakes as usual.

If I'm flushing the system then I use a full 32 oz bottle of DOT 3/4 synthetic brake fluid. Brake fluid really isn't that expensive. In my opinion its a good thing to flush as much fluid through the system. I've read that a brake flush is recommended every two to three years.

When I bled the brakes last summer (probably been 10 years since last done) the fluid was nasty. There were a lot of rust particles. I just bled the brakes again this weekend and the fluid was a little brown but there were no rust particles. So I'm a little more confident that my brake lines aren't going to fail on me.