I have a 2001 DRV 3500 5.9L.

3 times in the past year my front disc brakes have all but seized up to the extent it was difficult to get off the road. This would come on after driving at higher speeds (50+), gradually at first where some resistance was felt rolling up to a red light then within the next mile or two make it impossible to drive because of the resistance. In all 3 cases the heat at the front rims was extremely high, you could feel (and smell it) just standing next to the wheel which would burn you if you touched it.

I started with a brake fluid flush along with replacing the front rubber hoses. It seemed like that did the trick until same problem a few months later.

So next the calipers and disc pads were replaced. Shortly after that and only slightly at first and then so serious I parked the van because the brake pedal would slowly go to the floor even if pumped. Bleeding all 4 wheels didn't help. Turned out one of the rear drum brake cylinders had started leaking so they have now both been replaced. The pedal to the floor problem is definitely fixed and I don't think it ever had anything to do with the front rims overheating.

Now, with new front rubber lines, new front calipers and disc pads and new rear drum cylinders, I haven't had the extreme front wheel overheat but I know they're getting too hot. With a cold engine I can drive as little as a few miles with little braking at top speed no more than 45 and both front rims are already hot- too hot to touch for more than a few seconds. I know my van and those rims should have been from cool to slightly warm.

It seems like the master cylinder is the next (and last) possible brake part fix (the metal brake lines look fine) but before I sink the money in that too I'd like to know if there's a way I can test the master cylinder while still installed? Also could there be something else like wheel bearings causing this drag? The bearings are well greased and not making any odd sounds though and even if a bearing was bad how could that lock up my brakes?

Thanks in advance.

 

Normally, I would say the soft lines are the problem, but, as you have already replaced them..... that *shouldn't* be the case..... Caliper guide pins? Brake pedal adjustment?? If the pedal isn't letting the M/C fully retract, it may be leaving some residual pressure in the lines... which builds up the more you use the brakes.. Try jacking up the front end, spin the tires, see how they feel. Then go stomp on the brake pedal a couple times, and try again. Feel any difference???

 

Remove the master cylinder, then remove the pushrod behind it from the booster. Usually these pushrods are adjustable, if yours is, turn the end in 1 turn, reassemble and see the issue is gone. If this pushrod is too long, it will keep the brakes partially applied.

 

Thanks, I will try this. By 1 turn would that be like 360 degrees all the way around and to shorten this rod would that be clockwise? Follow this by bleeding brakes??

 

Yes, turn it clockwise to shorten it. I would do one full turn and see what happens. If you go too far, the more you shorten it, the more play you end up with at the brake pedal. No need to bleed the brakes unless you crack open a brake fitting. Often, you can leave the brake lines connected and just pull the MC forward and over a bit, just enough to slide the pushrod out.

Keep in mind, at some point they did away with the adjustable rod in favor of a solid one. I just can remember when they made this change. So, if you don't see a tip on yours with thread behind it, then this isn't the problem.