Chrysler Town & Country Intermittent Brake Failure

The brake pedal on my wife's 2011 town and country intermittently goes to the floor when braking!!! This problem became more frequent after a local shop replaced the left rear caliper. I replaced the master cylinder and used a pressurized bleeder to bleed the system and thought I had it fixed till the problem returned again about a month ago. I took the car for a test drive exercising the brakes under rough road conditions and activating the anti lock function at least a half a dozen times. The brakes worked perfectly. Brake fluid level is normal, no obvious leaks, all pads have very little wear.
Is there some extra step required when bleeding that is involves manually activating the anti lock brake module?

I bit the bullet and took the vehicle to the dealer. The Dealer couldn't find anything wrong but recommend that they change the master cylinder, which I replaced about 6 months ago, and the two rear brake calipers because they were known to give trouble. I said no thanks. I can throw parts at it a lot cheaper than them. So I ordered a shop manual cd from Faxon for $194 and an ABS modulator from mymoparparts.com for $229. If anyone has tips or cautions about changing the modulator please share.

Finally got the shop manual from Faxon. (When they say two weeks to deliver they mean it.)

So the shop manual installation procedure states the following:

"The base brake's hydraulic system must be bled anytime air enters the hydraulic system. The ABS must always be bled anytime it is suspected that the HCU (Hydraulic Control Unit) has ingested air.
Brake systems with ABS must be bled as two independent braking systems. The non-ABS portion of the brake system with ABS is to be bled the same as any non-ABS system.
The ABS portion of the brake system must be bled separately. Use the following procedure to properly bleed the brake hydraulic system including theABS."

Included in the instructions is this step:

"Using the scan tool, select ECU VIEW, followed by ABS MISCELLANEOUS FUNCTIONS to access bleeding. Follow the instructions displayed. When finished, disconnect the scan tool and proceed."

Finally got the hydraulic modulator module replaced and successfully bled three out of four wheel calipers but the right rear would not flow any fluid. Checked the bleeder and it was not plugged.

Drove vehicle in wet conditions, braking hard and activating ABS. Right rear is still not operating.

Two questions, 1. What brand and model non-OEM scanner will read the ABS bleed instructions and command the ABS module to perform the required operations? and 2. Can someone share what those instructions are with the intent to perform the bleed procedure without the scanner?

Sorry for the length of this post.

Appreciate your comments and suggestions.

Reluctant Mechanic

I've had an issue with air in my ABS. I bought an Autel Maxisys 906 for under $1k new and with one year warranty and one year of updates. It bled my ABS nicely. There different versions of the 906 (one is blue tooth for example). Mine is the basic corded one. It will give you the instructions. Really simple. Bleed your brakes normally. Then go thru the ABS bleed procedure. It takes about two minutes and all you do is hold your foot on the brake while the tool activates the pump. Then you bleed your brakes like normal again. Firmed my pedal right up and fixed my brakes. Can't say for certain if it will work on your car, but if it does a 98 I would think it would do an 11.

An Autel will definitely do the job, as rockp2 said. Most Snap-On scanners will work as well, provided they're even halfway recently updated.

As far as not getting fluid out of the right rear, I think you're doing it correctly. Even without the scanner, activating the ABS pump and solenoids during a hard stop should have been good enough to get fluid moving. You've got the manual, but I gotta ask - Have you been bleeding in the specified order? LR-RF-RR-LF. Some vehicles are super picky about this, and just won't be happy otherwise.

Is the right rear piston still fully retracted in the caliper? If so, it may be necessary to 'unwind' the piston out of it's bore, as to be closer to the pads. It sounds weird, but these calipers are never happy in their fully retracted position, and usually need help making full contact with the pads. Speaking of, have you tried using the parking brake? That can also help in seating a stubborn caliper.

Tyler, thanks for the ideas. Yes, I did follow the recommended order for bleeding after changing the hydrraulic module. I plan to break the right rear brake line loose at the hydraulic module and then apply the brakes to verify that the module is not allowing flow to the right rear. If it is allowing the right rear to be pressurized then I'll verify the caliper piston is in the right position so as not to restrict movement.
I really appreciate the comments and suggestions!
Reluctant Mechanic

No problem, let us know what you find!

Not so short update: Replaced the right rear caliper thinking that somehow the fully retracted piston did not allow the fluid flow but it didn’t change anything. Reinstalled the old ABS hydraulic modulator which fixed the no flow to the right rear caliper problem. Performed standard bleed of brake systems and ABS bleed using scanner (Autel MS906). System appears to be working fine now. I suspect the new modulator was damaged in shipping. It was not adequately padded so that one of the support studs had poked thru the shipping box. I should not have accepted the delivery. It is possible that my original problem was inadequate bleeding of the system. This last time I pushed between one and two quarts of fluid thru the system. By the way the Motive Power Bleeder works great. Well worth the money. And the Autel MaxiSys MS906 scanner is really cool. Now I just need to fix all my family’s and friends’ cars to justify the cost.
Thanks for all the comments and suggestions.
Hope my experiences can help someone troubleshooting similar problems.

With the new toys, not so "reluctant" now are you?