Kinda long, but here goes...Going down a country road, I hit the brakes, and the pedal went to the floor. I didn't try to pump it back up, 'cause I wasn't going very fast. After I rolled to a stop, the pedal was back solid. As I headed home, I heard a grinding noise in the front brakes when I used them. Got home, and as I was changing the pads, the only one that was worn was the drivers side, inner. The rest of the pads still looked good, on both sides. I replaced all four pads. About 8000 miles later, same thing happened; lost pedal, then the grinding noise again. Pulled the front wheels, and the same results (drivers side, inner, was worn to backing). Pulled the rear hubs just to check, and lo and behold, left side wheel cylinder was leaking everywhere. Replaced both rotors and all pads, rear wheel cylinders and shoes, rebuilt adjusters, etc. I also replaced the front brake hoses.

Right after doing this, the brakes felt really bad. I can feel "pulsing" when I use the brakes, kind of like ABS, but at all speeds. I haven't tried, but I have the feeling that I could push through the pedal if I tried hard enough. Also, I began to get the most God-awful shudder when I am breaking between 35 and 40 MPH.

Here's the kicker...Same song, third (?) verse about 6000 miles later, except now it was the PASSENGER side inner pad that was worn down!!! :'(

I hate to throw parts at it (anymore than I have), but I'm thinking the master cylinder is next, although I had one mechanic say it might be the proportioning valve.

Do you guys have any ideas? Thanks in advance for your replies.

Edit: Took out the "placeholder"

 

Here goes with my humble opinion and please don't be offended if this sounds to simple. I have had similar problems on a 95 1/2 ton. Check your fluid levels, your master cylnder mounting bolts, master cylinder gaskets/seals and check your calipers for binding. A stuck piston in the front on one side or another is common. If you find a stuck piston, rebuild and make sure you lubricate all the moving parts with a high temp brake grease. Rear drums also may need to have wheel cylinder work and adjustments. Check your rotors for lateral runnout. Heck just turn them or replace them and you may check your proportinoing valve. I assume you have 2 wheel ABS. I guess that is almost an entire check of the braking system but I am a rookie back yard mechanic and only have my own experience to go by. Hope I have shed some light in my rambling.

 

Thanks for your reply. I've pretty much done everything you suggested, short of replacing the master cylinder. I think I'm going to take my truck to the local mechanic and have him pressure bleed the entire system to at least eliminate the possibility of air in the system. I don't know anything about ABS, but hopefully he does. That's really what it feels like to me. If that doesn't fix it, then I guess it's on to replacing the master cylinder and/or the proportioning valve.

Thanks again.

 

A pulse usually indicates a warped rotor, an out of round drum, or the possiblilty of dirt, brake fluid ect, on the drum....

 

I'd go with the warped rotor idea...if the front inner pads wore down to the backing plates, it would not take much "normal" braking to create enough heat to warp or distort those rotors.

 

not sure what king of pulsation you have and weather its from the front or rear or if you know. a vibration in the seat usually means the drums are out and if you can feel it when ur going down the road without aplying the brakes. the rear brakes can be adjusted to tight and the drums out of round. replace the drums if this is the case the fact that one pad on the front is wearing and the others are good is an indication that the caliper slides are not lubricated properly. replace and repair slides/calipers as needed. since u changed out the rear wheel cylinders is sounds like you may have air in the lines which is giving you the soft pedal. did the master ever run dry due to the leak? a master that has gone to the floor a fews time could also start bypassing as the older seals in it could have broken when the cylinder went past its normal point. Id start by replacing the drum if that where the vibration is coming from(as the truck rolls slowly, slowly apply the parking brake and see if the truck shudders to the vibration)then a good fluid bleed and go from there.

 

TJinTX,
If I were you I'd 'edit' the *#@! before an admin. raps your nuckles. Just a hint. Go to the following.

http://www.dodge-diesel.org/yabbse/i...threadid=19887

 

As I read the rules, you can say *@%& all you want, you just can't use symbols instead of letters to sneak cussin' past the censoring software. For example, replacing "s" with "$" if you get my meaning.

 

If the pedal went to the floor, then something had to give way to the hydraulic pressure, I.E. a seal, if no leaking fluid was found, I'd say the master cyl is by passing. How you descibed the shuttering when applying the brakes means a warped rotor. For it to eat up one side of the pads, I would think that you have a caliper sticking. It'd be cheaper to replace the calipers. rotors and pads, maybe even the master cyl and proportioning valve, than have a total failure and crash and hurt yourself or someone else. I had a Furd a few years back that actually cracked the rotor.
Admin has a big bad ruler for rapping knuckles, just like when we was in school, just hope he doesn't have wart on his nose and ride a broom like my 3rd grade teacher did.

 

First of all, thanks to everyone for your replies. I think I'll just start over. I'll pull the drums and rotors and have them turned; rebuild the (new) calipers, and make sure that the pistons are properly lubed; check/replace pads and shoes. I'm very suspicious of the master cylinder, so I'll go ahead and replace that, as well.

Does anyone know the procedure, or can point me in the right direction, to bleed the entire brake system? I don't know for sure if the master cylinder went completely dry when the wheel cylinder blew, but I'll bench bleed the master cylinder when I replace it, and will bleed the lines at the caliper/wheel cylinder. Is there any way a back-yard mechanic can bleed the entire system, including ABS (if that even needs it)? I'm kinda grabbing at straws here.

Lastly, thanks for pointing out that I sorta broke the site rules in my first post. I edited it, and will keep that in mind for future posts.

 

Make sure you check the slides for thre front calipers to make sure the caliper floats freely. another thing is REPLACE THOSE CHEEESY FLEX LINES to the front calipers, those things actually cause alot of trouble and if anyone has used a pair of visegrips on them to pinch off the fliud while changing the calipers they will most certainly be junk.

One more thing to consider is when the pedal had gone to the floor is it possible the brake pad material let go from the backing plate?? have seen this more than once myself..

Dont go cheap on the brakes on these things, there mickey mouse to begin with...



Good luck

Jason

 

Bleed the master cylinder rear first and then the front. Do the combination valve and then the RWAl valve in the same manner as the master cylinder. Go to the right rear, then the left rear, then the right front and finish with the left front. 4 wheel ABS is slightly different, get back to me if you need that procedure. It has a special tool or 2 and is a dealer service in some circumstances as far as I know. I will help as much as I can.