I have never once had a problem with air getting stuck in the abs solenoids. I also don't use 2 people to bleed. I either use a pressure bleeder, or a mightyvac to suck it out through the caliper. Gravity bleeding works well too, but takes longer. Just stick the brake fluid bottle on top of the master reservoir and bleed it anyway ya want.

If you do get some stuck in there, just go make some abs stops in some dirt or something, then bleed it again. Highly doubt it'll be a problem though.

 

And it's not a special tool, it's just a scanner that can activate the abs pump and valves. You can do the same thing by activating the abs when driving.

 

I see, I should have read it closer. I thought you were replacing the master and abs unit.

You're not going to have a problem. No air is going to get into the abs unit unless you run the master cylinder dry. So don't do that. Prop the brake pedal down with something before you open the system. This will have the same effect as plugging a straw and taking it out of the water. The water stays in the straw, right? Same thing here. It'll keep all the fluid in the system.

Once finished, just flush all the fluid out until it's clear coming out of the calipers and you're done.

 

He is trying to get all the fluid even the stuff in the ABS labyrinth cleaned out

i wouldn't worry about cycling anything I have the ability but have never even tried it ( flushed twice )


but to answer the question other than IDS or Auto Enginuity I don't know of a Hack

 

Yeah I gathered, eventually. It's a good thing to do too. Can't tell ya how many times I've seen fresh brakes installed and the fluid is black.


Definitely don't worry about it. All fluid runs through the abs at all times, even under normal braking. I suppose there's a small pathway inside the unit from the dump valve back to the pump, if it even has a pump, that won't get flushed, but it's a non issue. It'll get clean fluid too once it's driven.

 

I hate when people hijack threads, but this is along the same lines, so I apologize to the OP, and anyone else who may be insulted

Another shop sent me a truck they failed to fix. New calipers all the way around, bleed, etc.
They replaced abs sensors, rotors, and vss.
Told the owner it needed a master cyl. There are no codes, The 3rd brake bulb was out, so I replaced it.
I was skeptical, ended up replacing 2 bad rubber lines, and 2 rusted steel lines.

Eventually running a full gallon of brake fluid through the system, I replaced master cyl. Pedal still creeps to the floor holding brakes like at a stop light.

At this point, customer wants to replace abs pump and module with a known good unit.

Do I just power bleed the system after the module change just like when I put the master cyl in?

I have clear brake fluid coming out now.

 

Key off, pump the brakes until the assist is gone and the pedal gets hard, does it still sink to the floor? If so, and you're convinced there are no leaks and it's not the master cylinder, then I suppose a dump valve could be just slightly stuck open, if that's the case, a few abs stops may un-stick it. I've yet to ever see this happen though.

But we're getting ahead of our selves.

And yes, you would bleed it exactly the same as you normally would. If air does get stuck, which it probably won't, activate the abs a few times while bleeding.

 

..

 

I am sure no leaks. Went so far as to even replace the copper washers on line that is good, but I suspected a leak. I have been through it, and am confident I have all the leaks solved.
I think I will take it for some good windshield kissing trips tomorrow, then get back to you. Thanks for the help

 

Took it for the shake down like you said.
First time nailing the brakes, it was like old school, rear end tried to pass the front, all 4 wheels locked up.

Second time, the ABS pump kind of farted, and shook the pedal.
I kept it up, each time, the brakes got better and better, it is acting like an ABS truck now, you hear the pump, and it hammers your foot. Truck stops straight as can be.

It still has a creep down pedal on sitting and holding the brake.

I am going to power bleed it again this week, and see what happens, but I have no way to do the 40 mph bleed like you said.
Any sugestions?

 

You just activate the abs to move the bubbles that are stuck in there. Hopefully jar them around and then go back and bleed it again. The idea being that the bubbles won't be stuck anymore. Don't really need a scanner for it, abs stops while driving should do the same thing.

So if the pedal gets hard, but sinks, that's not air, it's bypassing, or leaking internally. The only places is can do that is the master cylinder, or possibly the abs unit.

 

I replaced the master cylinder when I was doing the line repairs, so if this round of pressure bleeding dont firm up the pedal, I will replace the unit. I will get back to you with the results.
Thanks for the help.

 

OBS's had a TSB for the booster being bad causing a Sinking pedal, mine has done it the last 5 or 6 years i've owned it. Just never got around to replacing it because it still stops great.

 

i solved the "sinking pedal" on my 89 by putting the F-SuperDuty master cylinder on it.
it uses a 1 3/8 bore piston in the master instead of the 1 1/4 the 250 and 350 uses, and the 1 1/8 piston in the 150

i had enlarge the mounting hole in the booster by a few thousands, and oblong the holes in the mount on the master, but it worked much better than the smaller piston master.

 

So moving to a larger piston in the master would actually lead to less psi being transferred to the calipers.

Small piston to large piston multiplies the force, but lessons the distance.
Large piston to small piston multiplies the distance moved, but lessons the force.

So the calipers would grab quicker than usual, but wouldn't squeeze as hard. Must not have been too big of a difference or you would have known it right away.

 

This isn't the master cylinder.
Another shop did a brake job on the truck, and left the brake hose off, while they waited on a caliper delivery ( finally got a straight answer this morning)
The master cylinder ran out of fluid, causing the ABS pump to suck air.

There are ports and valves in there that can't be bled in the conventional way.

Going to try another pressure bleed this morning, because I got the pump to start working Saturday, and have my fingers crossed all functions properly when that one is complete.

 

oh, ok. that is why i do not let "techs" touch anything. if you do not call yourself a mechanic, you are nothing more than a parts changer.

 

Not even close.

 

Sad thing, this guy swear by this mechanic.
" been going to this guy for 40 years"

 

The techs are the most valuable asset in the shop. Often times the mechanics make more money for the shop, at least on paper anyway.

It gets complicated how that actually works out.

 

I give a lot of respect to the techs that I have run across. They have a lot to cover, the field keeps changing.

I am old school, but willing to learn. I think what Tom is seeing is the old school wanna be techs that don't want to expand and learn, and send jobs like the one I inherited away when they are at a loss.

Those guys are the ones that make it look bad for the work force that does keep up.

I appreciate the help Brother James is giving me, and That goes for some others here that have helped me in some of my problems I run into.


Thanks.
If I can pay it forward, or return the favor, so be it

 

what i meant was techs will read the symptoms and tell you this is bad, change it.
a mechanic will actually look at the vehicle, take it for a test drive, and try making adjustments if necessary before just replacing a part.

at least that is how they do it around here.

 

I didn't know there was a difference I am an ASE Certified Master Tech. Who has been A mechanic all his life.[emoji848][emoji848][emoji848] And hey everyone can have a bad day I'm about to have one starting on a "Bullet Proofed" 6.oh with misfires.

I was born into Gobernment health care. And will die in Gobernment Health care. God Bless Our Military Men And Women.

 

Depends on who you talk to, but mechanics are the nut and bolts guys and techs tend to be more skilled in the diagnostic department. Usually geared towards electrical. That's how I break it down. Both are nearly equally important, A good shop will have both.

On paper, the guys who turns the most hours are the biggest money makers. In reality, the techs are the ones who allow your shop to fix anything that comes in. Also the guys who get effed in the A because you charge three hours for diag when it takes three days to figure it out. I work on everything from hybrids to diesels. Sometimes I spend days on the same car trying to figure out one freaking problem.

Sh*t, I spent, all together, over a month on a Chrysler 200s where the a network was coming on an draining the battery. Consistently intermittent, what a nightmare that car was.

Anyway, no biggie, my feelings weren't hurt or anything. Just trying to clarify what a tech actually does.

 

I've been a bit absent since I initially posted this. First, no worries on hijacking the thread. Looks like it helped you out! Second, I'll follow the recommendations and just skip the ABS purge unless I have soft pedal issues that a normal bleed doesn't fix.

Thanks!

 

Good choice

 

I feel you wont have a problem with your purge. My nemesis is here. I'll post the power bleeder pictures when I get it set up.

Thanks for letting me hijack the thread

 

Bleed almost a quart through it, even bleed the master again, and the pedal still drifts.
Abs is working on panic stops.
Not sure where to look at this point, been all over it, I have no leaks.

Here are the pictures of the bleeder as promised

 

Found the problem.
Went to bleeding old school way. Caliper is stuck