2001 Dodge ram brake problem

Until about a week ago, no problems. I had a complete brake job last year.
I noticed recently that the brakes were taking longer to stop. I just figured I wore the pads out again, I drive a lot and am somewhat led
footed. But going home yesterday, the pedal on the truck would go most of the way to the floor and was very spongy. The truck would stop but the harder I pushed the pedal, it didn't seem to change how fast I was stopping. Kind of like stopping a ship at sea. On the way home, the ABS and Brake light both came on. I stopped and found that the master cylinder resovoir was almost empty.
I stopped at a local shop and had it checked expecting to find that I had a leaking caliper at 98K miles. The mechanic looked at it and said he didn't see any leaks on the front or back and that I had 70% wear left on all of my pads. He felt that the last people who did my brake job might have bled the brakes but not refilled the tank.
When I left, the ABS light and brake light were still on but he said that the ABS unit needed a few miles to get filled back up and that it should go off. The brakes seemed better but still not normal. I drove it to work today and the lights are still on after about 40 miles. Braking is back to being terrible.
Any ideas? A leak he didn't notice? A bad ABS unit?
Thanks, Michael
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@gmail.com wrote:

Did the mechanic blead the brakes again? Maybe a bad master cylinder, hole in the diaphragm etc.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I called the mechanic and that is exactly what he said. I asked if it could possibly be the ABS pump or unit and he said it would be a first for him on a vehicle that young. He said that he thinks it could be a bad master cylinder caused by air getting into it. He wants me to come back in and double check the engine codes to make sure no ABS information is sending and then replace the master cylinder.
I read an article that described my condition exactly: One classic symptom of a master cylinder that is leaking internally is a brake pedal that slowly sinks when you maintain pressure on it with your foot. Instead of a nice, firm pedal, the pedal slowly sinks and may go all the way to the floor.
The mechanic mentioned bench bleeding the cylinder as the article did so I think this is a very honest mechanic. He could have taken me last night for a haul because I was desperate but took me in right at closing time and gave it a once over.
Thanks, Michael
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Michael writes: The mechanic mentioned bench bleeding the cylinder as the article did so I think this is a very honest mechanic. He could have taken me last
night for a haul because I was desperate but took me in right at closing time and gave it a once over.
Thanks, Michael
He may be honest, but I doubt he's "good". If there were no leaks in the lines or at the calipers, then it has to be in the master cylinder. Sure, you're fluid level will drop as your breakes wear, but not to the extent you describe unless all the pads are down to metal.
If your fluid level is low again, you'll find you need a new master cylinder and that will end your problems. If your fluid level is still at the top, check the booster and the vacuum line going to it.
Since your pedal slowly goes down to the floor, my guess would be a master cylinder replacement is in order because the pressure isn't being held due to a leak.
Hope this helps.
Hank
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
The Master Cylinder was the problem....$400 later I am not a happy camper but it stops like it is new again.
The bad news is that the same thing has happened to my wife's van but her's hasn't hit rock bottom like mine did.
Thanks, Michael
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Don't even consider delaying the repair. They fail without warning as well, and you've been warned. Don't let a collision be the impetus for making the repair.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Did you check your fluid level again?
--
If at first you don't succeed, you're not cut out for skydiving
< snipped-for-privacy@gmail.com> wrote in message
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.