My 1996 E350 van has been sitting for about six weeks. Prior to that my ABS light had come on and stayed on but no issues with the brakes. I'd read this means there is a sensor that is acting up, dirty, etc. but will not affect normal brake use.

Brakes were rebuilt when I got the van about two years ago. New brakes lines to wheels, all new rotors, all new calipers & brakes shoes. I completely bled the system and they worked perfect! I'm the only driver and I always go easy on my brakes.

Today, in starting it up, the brake light also came on and the pedal was mushy. Would slowly go to the floor. Brakes were working (around the parking lot only) but this is certainly not normal.

Moved the van and there was not a drop of brake fluid anywhere on the pavement. Nothing appears wet up front. Brake fluid at the fill line.

Advice please.

 

How does the pedal feel with the engine off ? Inspect the Vacuum line from the manifold to the booster as a leak / bad seal / cracked manifold would or could cause this...If connection is solid and you can still do what you said , I would be looking at a new booster...Also If you listen with the hood open and someone else pushing on the pedal a whooshing type noise , this also indicates a cooked booster.....

 

0ne of the sensors in that system almost definitely needs replaced or cleaned. Using a code scanner should indicate which sensor--I'd guess its the rear center differential one myself but could be any of them. Such an code fault will not affect your normal braking action however the ABS function may not work if its called for.

As mentioned your booster chamber could be at fault but I'd check the master cylinder as well---fluid could be leaking past the piston, especially if there's no sign of a leaking wheel cylinder or brake line.

 

If the old Brake Fluid was thick and black (burnt), the new fluid will clean out the Master Cylinder Seals and cause it to leak, and or loose line pressure, easy test is to hold the brake pedal down firmly and see if it slowly goes all the way to the floor. I did the same repair on my Motorhome once and washer on the Brake Caliper Flex Hose cracked and the system sucked air after setting a few weeks and gave me a funny mushy pedal............it was hard to find!

 

Exactly........If you have not flushed the fluid in the last 2 years......that is also a issue

 

With the engine off the pedal feels normal. Firm and not going down. Engine on and it's mushy. Will go slowly to the floor if I press on it.

There is a large hose going to the booster (large black plastic case in back of master cylinder?) from over the top of the air filter. All looks good. No cracks & rubber pliable. Felt as far as I could in towards engine. Did not remove dog house yet.

[/QUOTE]If connection is solid and you can still do what you said I would be looking at a new booster...Also If you listen with the hood open and someone else pushing on the pedal a whooshing type noise , this also indicates a cooked booster.....[/QUOTE]

Do I try this engine on or off?

From what I've told you so far, you're pretty sure it's the booster? Would it just fail from sitting?
Can I do this myself. Costs for a booster? The one in there is a Bosch. OK to use same or ??

BTW: Why the brake light? Parking brakes are off and still the light remains?

Thanks for help on this. Much appreciated.

 

It ran fine for almost two years. I'd think this would happen right after the repairs, correct?

 

Engine running: air in the lines the pedal can be low and or mushy, firmly holding the pedal and it's slowly going to the floor over and over, (Warning) complete brake failure and loss of all brake functions can happen at anytime! If your not sure, it's time to tow it to your local Brake shop before something bad happens..........

 

If the brakes are firm with engine off does that not mean no air in system?

You bleed them with the engine off. They feel the same as always with engine off.

Confused.

 

Scooter not trying to be rude or short with you but working with your brakes and the engine not running tells you absolutely nothing!

This is because the booster (even if considered bad or defective) offers significant resistance to brake pedal operation because you're fighting against the large rubber diaphragm inside the metal chamber. Under vacuum is how the brake system works properly so anything you attempt to do without the engine running shows you nothing.

Your questions about engine off might be what's confusing you---forget that and all this might make more sense.

Not to doubt your DIY abilities but at some point if this continues to be a problem it might be best to tow you van to a competent shop. Costly yes but much less so than any accidents due faulty brakes!

Stay safe and let us know your progress please------we're hoping for the best!

 

Found this article that seems to match my problem exactly.

Kelsey-Hayes RWAL Antilock Brakes

 

Ok are you ready for a long story, we have a 1994 E350 ours is diesel but brakes are pretty much the same except the diesel has a vacuum pump to supply vacuum to the booster, one day while driving I hit the brakes and like yours my pedal felt mushy i guess would be the word, well the truck stopped ok but the pedal would go to the floor if I kept pushing on the pedal, so when I got back to the office I called our repair shop and told them to order everything because the truck was 18 yrs old and the last brake job was three yrs ago and the rotors could not be turned again so when they had all the parts rotors, drums, mastercylinder, wheel cylinders, calipers, spring kits brake pads, shoes for the rear, new brake lines rubber and steel, a big chunk of change but this truck is our money maker. Took it in on a friday morning and they got right to work on it Truck was to be ready Monday morning since they had all day friday and saturday, Came to office on monday morning no truck on the lot call my mechanic and he said they were having trouble bleeding the brakes they had bled for several hrs saturday and could not get a pedal and to give them a couple hrs to bleed it out so 10 am and I call and they are still nowhere, we talked about my experence with it truck when the brakes failed and he said well we have a pedal without it running but when we start it the pedal will go to the floor if ya push hard enough. so I went down there and sure enough same exact feel I had when they failed I even drove it and it would stop good but as I sat there with my foot on the pedal if i pushed, down it would go, But I didnt have to push the pedal the truck would stay stopped I even power braked the thing and it would not move with very little pressure on the pedal So the mechanic took the truck back in the shop they installed a new vacuum pump, did not help they bypassed the antilock valve, no help. tested and retested mastercylinder even put a second one on no help, so now it was wednesday not only am i spending money Im loosing money. everything has been replaced and no pedal same symptons call a friend of my that had a fleet of the same trucks a few years ago. I told him the problem and before I could tell him everything we installed he said put a new booster on it, they had 4 trucks do the same thing and after spending a butt load of money on the first one Like I did The booster was bad I dont know what kind of failure occures but we replaed the booster and Boom we had the best brakes that we ever had Plus we never reinstalled that antilock valve for the rear but we are heavy, alwayes 11,500 lbs so we dont experence rear wheels locking up. I hope you hit the problem quick because our brake job about broke the bank. so pull the wheels and do a inspection if good adjust the rear brakes, you can bypass the antilock to test, napa has the fittings you need, bench test the mastercylinder, check for rubber brake lines swelling when pedal is pushed, as for testing the booster I have no idea the normal test does not indicate a problem with booster we were sure it was working properly We were wrong.

 

Make sure your rear brakes are adjusted properly! You will get a sloppy brake peddle if they are not good and tight!

Pull the wheels and drums and look to see if you have any wetness in the drum area, if so you have a bad wheel cylinder! If not adjust your brakes while you are there.

 

It appears the brakes are/were fine after all. Not having used the van for several months I can only assume the "feel" I was getting was due to the difference between my recently purchased 1997 Ford Ranger and the Toyota I've been driving daily.

I took the van for a ride today and all is well. It stops like it used to. Pedal seems to be a bit firmer after the engine is running for a spell.

I still have the ABS light on. Cleaned the contacts for the electrical cable connectors for both front wheels using Caig contact restorer. Light stays on.

I still have the parking brake light on. Checked the switch at the pedal and it appears good. Pedal down (brake engaged) and the switch is closed. Pedal up and the switch open.

Is there a fuse for the parking brake? Seems counter-intuitive if there is... for the light to remain lit when the fuse is open (bad), but then again if the fuse was burned out and the light was always off how would you know the brakes were released?

 

I have the ABS light on issue, the previous owner (and original owner) said the light was on for years, the shop said it's probably a faulty sensor and no braking issues result from it. While the van does stop properly with no issues, I'd still like to get this figured out. Is there a key dance that can pull the code on the dash or is a code reader needed?