Thanks for posting MORE useless information I'm not using my experience as a weapon, if you had any yourself, you'd know that.

 

Hi All,

I've been experiencing brake issues with my wife's 2004 E-250 SRW 4WABS Discs, Short Van (Conversion). About 4 months after I did the brakes (normal wear, no issues) the brakes worked perfectly. The van has ~ 98K miles. She complained of a low pedal, and sinking to the floor. Of course my initial presumption was a bad MC. I replaced the MC, but no joy. The thought then became that while the pedal was being depressed, there was a hissing sound. So I thought, maybe I missed it and the Booster was bad (although typically when boosters go bad, the pedal becomes very hard and sometimes the engine will run rougher due to a vacuum leak). I replaced the booster, but still no joy. Initially I thought (forgetting that it was 4WABS and thinking that the KH Dump valve was possibly the problem 2WABS) I looked and realized that I'd forgotten (mostly due to reading blogs describing the exact symptoms I was experiencing).

At any rate, the problem has not been corrected at this writing. There are no ABS warning lights, there are no external leaks, the the brake system has been throughly bled), I'm left thinking that perhaps the ABS Module/Pump assembly is the culprit. Perhaps, as in the case of the 2WABS dump valve, the 4WABS module has an internal leak, or is stuck in a bypass mode. The Module identifier is 4C24-2C346-BB E250/E350. I've had no luck in finding an exact match, but I did find a used assembly identified as
4C24-2C346-BC.

I guess my questions to the forum are:

(a) Am I barking up the wrong tree since no faults are indicated (ABS light) and that the problem is primarily with the hydraulic portion of the assembly?or

(b) has anyone else experienced a similar failure and found that it was the electronic portion of the 4WABS assembly?

(c) Can the BC suffix be used for a replacement without hazard or (as seems by the information in some blogs) must the 4C24-2C346-BB module be used?

(d) I'm given to understand that the electronic portion of the 4WABS can be repaired (not sure it's bad). Has anyone used such a service or must the dealership perform the programming/repairs?

(e)Are there any simple tests I can perform to ascertain whether or not the 4WABS unit is defective, or must I purchase a brake system analysis tool (funds are limited, but correct diagnosis/repair is imperative

Thanks for any assistance in advance.

Bob J

 

That was true up until GM and Chrysler almost failed.
I have started to buy hard to get parts as back-ups for when they fail.

Back to the regularly scheduled thread.

 

I know this may seem almost impossible but I have run across a few bad master cylinders in the last few years. Most of them have been rebuilt and not new. Since mc's are cheap compared to the other parts I would consider replacing it again. The best way to test a mc is to apply pressure to the pedal without the engine running and see if the pedal will drift to the floor slowly. The second thing I would check is air in the lines. I don't care how many times you bleed the brakes you can still ge air. Check the lines and make sure they are tight and not bleeding off. The best way to bleed brakes on an abs system is the use a back bleeder system. That supplies fluid to the wheels and fills the system to the mc. If you have air in your abs pump it can be a nightmare to get the air out of it. You said there was no leaks that would be next for me to check. If there is not an ABS light on the system should be working. I would still say it needs a master cylinder then go from there. I know you don't want to take it to a dealer for repairs. Best of luck. Andy

 

Hi Guys,

Thanks for the replies and inputs. I neglected to say that I too tried a rebuilt MC when the problem first occurred. Thinking that I'd gotten a bad one, I decided to stop playing and bought a new MC, but still no joy (My fault, I should've mentioned it in the post -- I've seen bad replacement MCs too).

I looked up the link for the 4WABS repair site ModuleMaster, and their price seems reasonable. Not sure what the shipping charges would be, but I would think less than $50 both ways. I'm thinking I'll take that option as they have a 5-year warranty on their service. It may not be the issue, although I'm hard pressed to identify any other possible source for the problem. I also neglected to say that the brakes were replaced all the way around, so pad wear etc. isn't an issue. The emergency brake is fine, but of course, the mechanism is separate from the normal service brakes.

Again, thanks for the quick replies and suggestions.

Bob J

 

Makaibob please keep us updated on your progress, costs and results----if successful your input might prove valuable to others at a later date.

At any rate best of luck with your project.

 

Makaibob I hope you are able to repair your van. The only other thing I can think of is a hanging caliper. I have ran across a few to where the caliper would not pull all the way back and not make the car pull right or left if it was on the front. It does make it where the wheel will grab on loose or wet pavement. Of course sometimes it was do to a bad flexible hydraulic line also going to the caliper. If it is your ABS hydraulic unit I would be surprised. I was working on a BMW motorcycle with ABS and that thing drove me crazy. The ABS light would come on and I would loose the speedo at the same time or a rapid flashing. It would not do it all the time. Turned out to be a bad sensor wire on the rear wheel. The wire was broke almost in half. Keep us posted on what you find.
God Bless, Andy

 

Hi Guys ('n Gals too),

I've finally corrected the brake problem (the van sat until I could locate a replacement ABS Module that matched the original- never found, BTW). My apologies for the much delayed problem resolution. The problem was the ABS module. A new module listed for $1,000.00+ from Ford (yes, I realize I could get a 25% discount), but even then, the price seemed exorbitant. I finally found a compatible, though not the same exact P/N from a 2003 van. I located it from an EBAY west coast recycler for $100 plus shipping.

The symptoms can be, and were misleading, but here's how I made the determination of the problem. When bleeding the brakes (which I did several times to be certain that there was absolutely NO air in the system), I had a firm pedal, as some others have found to be true. However, when the engine was started, the brake pedal sunk to the floor with the hissing sound. It's worth noting that my diagnosis and parts replacement started with what I'd considered at the time, the most likely to the least likely. It's important to note that although a piecemeal approach can be less expensive, it doesn't guarantee success. I will confess, that most of my experience is "old school", and I've limited experience with ABS systems, hence the methodology I used.

My theory (later shown to resolve the issue) was that the ECU for the ABS module was either mis-interpreting the braking situation (I think this most likely) or the ABS Valve assembly was defective (possible, but if true, I would've thought that achieving a firm pedal would not be possible, engine on or not).

This is a long-winded way of saying, at least with 4WABS (SRW), the ABS module is highly suspect when experiencing the pedal to the floor accompanied by the hissing sound (pronounced). Perhaps you could think of it a mirroring the 2WABS system dump val issues that have been discussed previously.

Yes, I spent more than I should've/could've but the cost was still less that $500 (not cheap, and from my POV/experience logical) The total cost could've been less that $150. Note also, I didn't have an ABS diagnostic scanner, but my thought at the time was no warning lights, codes so the ABS waslikely OK (soooo not true)

Hope this helps anyone else experiencing similar problems, and saves them time and money.

Learning costs sometimes :^)

 

I'm having similar issues to makaibob with a '95 e350 dually except I also have the ABS light on (which never goes off when in ignition). This is a three-sensor system.

I literally contacted every mechanic in Vegas and not one had the diagnostic tool, so I broke down and bought one. Unfortunately, it can't connect to the ABS computer (F4UA-2C219-EG) so maybe I have a bad "module" (I'm assuming here the "module" is the computer and not the hydraulic unit with the solenoid pack (F4UA-2C286-AE).

 

Seems I read somewhere that dirty brake fluid will cause that too. My 96 E150's light stays on too, but I have no use for the antilock system so I just ignore it. The fluid in the reservoir is pretty dark, so that may be why it stays lit.

 

Mine is pristine

I found out this morning that my pedal doesn't floor (with the whoosh sound) when I start the engine IF I disconnect the hydraulic unit (12pin solenoid and 2pin pump connector). I could make it sink once after parking, however.

 

Sounds like you may have a bad master cylinder or bad booster.

 

Based on what?

If I had a bad master cylinder how come the pedal is firm when the engine isn't running?

If I had a bad booster I'd have no braking power.

 

Your "whoosh" comment and the pedal dropping. Or maybe I read that wrong

 

I have the same symptoms as post #23.

A pedal can drop for a variety of reasons. If a car does not have ABS, then it's probably the master cylinder. I don't see how it could be the master cylinder if it only drops if the engine is running (and then gets firm after two stomps).