Soft brakes. Any advice?

[GR_CoB]

2009 Pontiac Vibe, base model with 2.4L engine option. Same vehicle as Toyota Matrix.
- Rear caliper seized up. Passenger side seized up, but to be safe I replaced both rears. New pads, rotors, hardware.
- I was alone, so tried gravity bleeding. Took forever, seemed to work. First drive proved it was a fail, tons of air in the system.
- Once wife got home I got her to pump the brakes. Bled them properly this time, starting from the farthest. Pedal feel improved dramatically, when car is off.
- Test drive went well, but when engine is running the first 60% of pedal travel is nothing, followed by last 40% being the engagement point. Again, once engine is off - 100% of the pedal travel provides proper resistance.
- Logic tells me there is air in the ABS module/pump. Can't find any specific bleeding procedures for that on my vehicle.
- How bad of an idea is it to try to bleed the brakes again, but with the engine running? Or are there any other tricks you'd try first? I know some ABS modules have a bleeder valve, mine doesn't seem to have it. Unless it is well hidden, which defeats the purpose...
I'm open to any and all suggestions.

 

[slacktide_bitog]

speed bleeders are awesome

Yeah, you need the engine running to bleed the brakes. That's how I do it. There is nothing wrong with doing it that way.

You don't need to do any separate bleeding for the ABS, except in some early 90s Hondas.

 

[Nukeman7]

I have had good results in achieving a firm pedal by reverse bleeding the brake system with the Phoenix Systems device shown below. It will force trapped air bubbles in the ABS module back up into the master cylinder fluid reservoir.

 

[Sequoiasoon]

I use my Motive pressure bleeder if by myself. Not the easiest to get a seal all the time. If kids or wife are home lately has been 2 person, always with engine running.

 

[haggler]

I used a one way hydraulic valve I bought on amazon on the bleeder into a gatoraide bottle zip tied to a magnet. You just bleed the normal way but the valve stops air and dirty fluid from entering. Takes much less pumps.

 

[wpod]

Maybe the master cyl.

 

[eljefino]

Maybe get an old laptop and "Ebay tech stream", it may be able to bleed the ABS module in a way you can't without the tool.

 

[Gus_Mahn]

It might be worth activating the ABS. Find a gravel road, and stand on the brakes. My wife’s Infiniti had a terrible pedal after I let the master go dry while bleeding the rear. No amount of bleeding would bring the pedal back. Two good panic stops with ABS activation brought the pedal back.

 

[vwmaniaman]

Our Mazda5 had the pedal drop issue . I bought an ANCEL 610 and pumped the pedal several times to get it to come up and then activated the ABS pump with the tool and first the pedal dropped and then pumped my foot back to the top. It has to be able to have ABS activated to get the air out.

 

[John105]

I use my Motive pressure bleeder if by myself. Not the easiest to get a seal all the time. If kids or wife are home lately has been 2 person, always with engine running.

have done the same, only with engine off. When by myself I only use the Motive for air, i.e. no fluid in it.

As far as I know there is no need to touch the ABS, unless the pump was removed, which I did with my BMW for repair. In this case, if one listens to BMW, there is no way possible to evacuate the air using the brake pedal (some guys on the forum claim they have slammed on the brakes in the wet etc.). And so, they have an ABL procedure which actually the dealer is supposed to do if they replace a caliper or hose. The procedure electronically pulses each corner of the car via the ABS pump. Again, I don't think this is necessary but maybe I'm wrong (did calipers on my Maxima and never touched the ABS).

 

[GR_CoB]

I'll try the gravel road trick.
If it doesn't help, then I'll bleed again, but with engine on. For some reason I was taught to only bleed with engine off and key on mode. Always had success doing it that way, until now.

 

[BrainThicknessVariation]

speed bleeders are awesome

Yeah, you need the engine running to bleed the brakes. That's how I do it. There is nothing wrong with doing it that way.

You don't need to do any separate bleeding for the ABS, except in some early 90s Hondas.

I have had good results in achieving a firm pedal by reverse bleeding the brake system with the Phoenix Systems device shown below. It will force trapped air bubbles in the ABS module back up into the master cylinder fluid reservoir.

Consult with your vehicles service manual to know if the engine should be running or not. Mine need to be *off*.

Also prefer a brake pedal depressor over speed bleeders, because it's not vehicle specific and you don't have to worry about a malfunctioning bleeder. What I do is set it up, lock it in place, then I move the seat forward a little at a time (assuming you have electronic seat adjusters). No second person needed, and just need one free hand to depress the brake further .

If you don't want to go the brake pedal depressor route, you can just get a Motive Power Bleeder. Those things are great. Just make sure you don't have any blocked brake nipples say if you're working on an old vehicle. The brake fluid reservoir will overflow without you knowing it. Ask me how I know . Should work flawlessly however on any well-maintained vehicle.

 

[D60]

If you just replaced rear calipers there really shouldn't be air in ABS HCU unless you let the lines drip forever with calipers removed and ran the reservoir dry.

That said, on some vehicles I've had better results bleeding with engine running.

How exactly are you bleeding with a helper? Also, consider some grease on bleeder threads to stop air there.

 

[GR_CoB]

If you just replaced rear calipers there really shouldn't be air in ABS HCU unless you let the lines drip forever with calipers removed and ran the reservoir dry.

That said, on some vehicles I've had better results bleeding with engine running.

How exactly are you bleeding with a helper? Also, consider some grease on bleeder threads to stop air there.

- Yes that was the case. I removed calipers and took them to AutoZone 1hr away to avoid core charge when purchasing new ones. So the lines were disconnected for 2hrs+.

With a helper:
- I let them pump the brakes until pedal is hard
- then helper presses and holds the brake pedal
- I open the bleeder valve on caliper until pedal reaches the floor
- then close bleeder valve
- then repeat until no more air is coming out of the bleeder

 

[D60]

Ok I never let lines drip that long without being there to monitor it. If the rear circuit went dry you may need to bench bleed the master cylinder.

A reverse bleed may get around this.

As for using a helper, I try to close the bleeder before the pedal hits the floor. Ideally you want there to still be positive pressure when you close the bleeder.

 

[supton]

- Yes that was the case. I removed calipers and took them to AutoZone 1hr away to avoid core charge when purchasing new ones. So the lines were disconnected for 2hrs+.

I was afraid of that... I think I did that one time, and what I did was get piece of rubber, I think it was a bit of bicycle tube, and a clamp. A makeshift way to clamp the line off by putting over the banjo fitting and clamping shut. Note, one does not want to crimp the rubber line and damage it! But any way of stopping up the line (sans damaging the line) is wise. That or have someone keep dumping in fresh brake fluid (I guess that's one way to flush the brake line).

One hour drive each way? ok I can understand the desire to not make the drive twice.

 

[D60]

I was afraid of that... I think I did that one time, and what I did was get piece of rubber, I think it was a bit of bicycle tube, and a clamp. A makeshift way to clamp the line off by putting over the banjo fitting and clamping shut. Note, one does not want to crimp the rubber line and damage it! But any way of stopping up the line (sans damaging the line) is wise. That or have someone keep dumping in fresh brake fluid (I guess that's one way to flush the brake line).

One hour drive each way? ok I can understand the desire to not make the drive twice.

Meh, just hang on to the receipt and turn 'em in next time you're in the area.

Or most recently I did clamp the hoses off because I knew I was getting new hoses (and they actually stocked them locally)

But anymore I send cores back with the O'Reilly driver the next time they deliver something else

 

[tnt_motorsports]

I have an old plastic candy jar that I drilled 2 holes in. I place a piece of plastic tube through the lid in the jar. I add about 1-1/2” of old fluid to the jar and place the hose over the bleed screw. Loosen the screw and pump your brakes until the fluid runs clean. Close the bleed screw and do the other side. I got 1-1/2 quarts of fluid out of my rear brakes when I did my Ram a couple months ago.

*** the hose in the jar must be submerged in the old fluid for this to work!

Very easy and cheap. Cost $3 for the plastic hose.

Just my $0.02

 

[DCinMA]

I think everyone is off point here. He said his car is eqvilent to an 09 toyota, I have a 2011 toyota. I had to do major brake work and expierenced the same problem.
There could be air in the ABS unit if you ran the master cylinder dry. On newer cars you either go to the dealer and pay alot to bleed the brkes or by a BI-DIRECTIONAL code scanner for between 100-300 $, these cars need a computer to bleed the abs unit.

 

[DCinMA]

Thats what I did because I replaced the Master Cylinder and could not get it bleed properly untill I bought the tool.