Brake bleeding: I must be doing it wrong

I'll admit to only ever having bled brakes once in the past, and this time around it's befuddling me.

2006 Accord EX V6 w ABS

I just replaced all four calipers with new after finding a couple were frozen, and there was a good deal on a full set thru Rock Auto.

I'm using the two-person method, with a tube going into a soda bottle partially filled with brake fluid. Brake reservoir is open, and I keep it topped up. I have SWMBO pump the brakes and depress the pedal, and I open the bleed nipple, filling the bottle til bubbles are gone (also fluid has run clear at this point). I did it LF->RF->RR->LR as the manual instructs. 

I've done the whole sequence 3 times now, bled til the fluid runs clear and no bubbles. Feels fine with firm pedal feel until I start the car and test drive. Then spongy pedal that goes to the floor, so there's air still in the system.

Didn't have this problem prior to replacing calipers, so I don't think it's the MC or a soft brake line. 

What gives?

Did the MC run dry while you had a caliper off?  Did you switch any of the calipers side to side so the bleeders aren't at the top? 

Bleeders are all at the top. I pinched the brake lines while I switched the caliper, so I don't believe the MC would have run dry.

You have a leak in one of the fittings/joints.  Inspect and retighten everything you had apart.

Try just gravity bleeding.  No pumping, just open one bleeder at a time and let it dribble.  

The rear calipers have a parking brake mechanism, or little shoes inside the rotor?  The screw type park brake can be a trouble spot.

When you apply the brakes, the pads clamp the rotors properly?  They are not pushing the pads out a bit, then pulling them back?

Are you sure the pedal is actually soft?  Lots of times people will push the pedal far harder than is required for a panic stop when testing.  If the pedal is real low on a test drive, it's a problem.  

Fresh calipers with soft seals will sometimes pull the pads back farther than the old ones did.  Usually goes away after a few heat cycles.

pedal is definitely soft when running - will go progressively to the floor under hard braking. Rears have that modern screw-type parking brake mechanism. 

I inspected the whole shebang and didn't see any leaks under braking. Fittings are torqued properly.

If it has good pedal when you start, then after a while doesn't, you have a leak somewhere.

I guess I wasn't clear, it's not good from the start when I turn on the car, doesn't feel like it's progressively worse. 

Do people have a one-man bleeder they're happy with? 

In reply to Erich :

Since it has ABS try it with the car running, or at least the key turned to "run". 

If SWMBO pumps too quickly and doesn't let the master re-fill, you will still have air in the system. 

Open bleeder, press pedal down & hold, close bleeder, release pedal, open bleeder & repeat cycle. "pumping" doesn't do anything. If she lifts before you close bleeder it just pulls fluid & bubbles back in.

Do people have a one-man bleeder they're happy with?

I made my own this past summer to deal with the stubborn hydraulic clutch circuit on my Trooper. Was surprised how well it works and can't imagine why anyone would shell out $$ for the retail pressure bleeders.

http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/

http://www.bayarea02.com/techtips/brake_bleeder.html

The only other suggestion I have is that the ABS module needs to be bled. Usually that is a special tool thing. Some type of software is needed to cause the ABS module to perform a special sequence to properly remove any air. This was a know problem for some cars I owned way back. The only solution was dealership. I remember talking to the Chrysler brake engineer and he confirmed it was the only way at the time as they wrote the code and encrypted it, and shared with only dealers. But hopefully the Honda guys like to share. 

Otherwise you say you pinched the brake hoses to prevent leaking all the fluid out. Some brake lines would fail an inner hose such that now your fluid pressure is escaping out of the inner tube and bulging out the outer rubber hose rather than leaking. 

I don't think it's the problem but I find it interesting the manual says to bleed in that order. I have always done it RR-LR-RF-LF.

It indeed sounds like you have a leak (check reservoir level) or air in the lines. Pinching lines is not best practice and could be causing an issue as well. 

I remember when brake bleeding used to be easy and painless.  Now I dread replacing the brake fluid on any of my modern cars.  They never seem to be the same after you crack them open.

Stroking the pedal of an old master can damage the internal seals if there's any crud in the bore.

spandak said:

I don't think it's the problem but I find it interesting the manual says to bleed in that order. I have always done it RR-LR-RF-LF.

It indeed sounds like you have a leak (check reservoir level) or air in the lines. Pinching lines is not best practice and could be causing an issue as well. 

This.  The sequence the manual says to do is almost the opposite of the universal/common sequence.

Try bleeding the lines at the MC first.  Air bubbles that far up may never reach the calipers.  Usually the ABS doesn't effect bleeding since it's normally in bypass mode unless activated, but if air was introduced you may not have a choice but to find a way to activate in while bleeding.

Thanks guys. Lots to troubleshoot. I'll start with inspecting the brake lines for bulging, and try bleeding at the MC. 

When the ABS unit is not actively controlling brake pressure, it is a pass-thru device.  It does not need to be bled.

Honda's do have a funny sequence. I did it normally then read in the manual I did it wrong. I'm really not sure what difference it makes as long as you get the air out but my pedal is softer after bleeding. I haven't gotten around to doing it as the manual States yet.

AngryCorvair said:

When the ABS unit is not actively controlling brake pressure, it is a pass-thru device.  It does not need to be bled.

Unless its a full size chevy truck i guess. Sounds like air in the lines too me, we had to bleed a friends suburban with it running to trick the abs pump and save a dealer trip.

The only time I've ever had bleeding issues related to the ABS system was when I put braided stainless lines on my Camaro and had pretty much the whole system run dry overnight due to fittings leaking. It was a lot like you describe above, bled them a million times, looked and felt great until I went to go drive it and the pedal immediately went soft.

Ultimately, what I ended up doing to fool the ABS into activating was spinning one of the front wheels by hand, while the car was up on jack stands and running, and having a buddy jam on the brakes. Did that a few times and it worked like a charm, bled just fine after that.

After much frustration trying to bleed the clutch in my LS1 RX7 project, I recently ended up picking up a cheap vacuum bleeder from Autozone. Two days of frustration was vanquished within 20 minutes and I immediately wondered why I hadn't bought one sooner. 

Some cars with diagonal systems  are bled RR LF LR RF. And some cars seem to only be able to bleed air out with a pressure system. Pumping the brakes too quickly is not good. 

Don49 said:

If SWMBO pumps too quickly and doesn't let the master re-fill, you will still have air in the system. 

Aaannnd, that can be interpreted more than one way...

NOT A TA said:

Open bleeder, press pedal down & hold, close bleeder, release pedal, open bleeder & repeat cycle. "pumping" doesn't do anything. If she lifts before you close bleeder it just pulls fluid & bubbles back in.

 

This is not right. 

Pump brakes three times and hold pressure on the peddle. Then open the bleeder. When peddle hits the floor keep pressure on it and close the bleeder. Then repeat.  This method will compress any air in the system and expelled it under pressure getting air bubbles out faster and more effectively.