My buddy has a 94 ram 2500 12 valve 5 speed. He was telling me the problems And it sounded like a brake booster.. I took it for a test drive today, and now im not so sure.

If you pump the brakes while the truck isnt moving, the pedal gets rock hard.. driving down the highway at 60 and try to gradually stop, it pulls hard to the left but still feels alright. I was thinking bad caliper, but he said both fronts are new.. Maybe the rubber line going to the caliper is bad?

Also, once it gets below say 15 mph for stopping at a stop sign.. the pedal gets softer and the abs kicks in and pretty much lose all stopping power.. feels like its slipping on ice..

I also noticed that if you hit the pedal for a fast stop, It just locks up the rear tires..

Brake booster? ABS motor? Proportioning valve?

Any help would be GREATLY appreciated

Ill also add that he bought a new master cylinder and brake booster for the truck, but i dont want to fix what isnt broke

 

Sounds like the rubber line to me. As far as the pulling.

 

Doesn't the diesel trucks use hydraboost? (as opposed to a vacuum booster?)

I would replace the front brakes lines, (both flex lines) and see what happens. It already sounds like one is bad.....

2 or 4 wheel ABS?

 

Assuming the flex lines are original, this is a good idea. Someone on a tractor forum had issues with his Dodge's brakes, and it turned out to be the proportioning valve.

So, just food for thought.

 

I believe it's 4 wheel abs, but not 100% sure

 

So this morning i pulled out the abs fuse and went for another test drive. All symptoms went away except for the pull to the left in the front. pretty sure its a bad rubber line in the front, so gonna replace both. pulled back in the driveway, plugged the abs fuse back in and disconnected the sensor on top of the pumpkin in the rear. took it for another test drive and symptoms were still gone. it stopped fine. So the sensor in the rear is bad??

 

One bad sensor disables the system. Could be any of the three that are failing... Need to plug in with a scanner, and have a look at the data from the three sensors, and see which one is lying.

Of course, there is always the real possibility that one caliper not doing squat is what is giving the system fits too.... So, fix the lines first, go for a drive, and see what ya get.

 

If he's going that far (replacing the flex lines), then I would suggest a complete flush of the brake system. The general rule for a complete system flush is 24-30 months, right?

 

Good point. In all reality, I know of very few people that bother to flush their brake systems, unless something fails..... (which is probably WHY some things fail.) Flushing out all the old fluid is never a bad idea, and, if you are going to be RIGHT THERE anyway, there is no reason why you shouldn't do it.

 

The three most important preventive maintenance items that people never consider are:

1. Coolant flush every three years
2. Transmission fluid & filter replacement with band adjustment every 30,000 miles
3. Brake fluid flush every 24-30 months