Like the title says, what is the difference in distribution between the rear drum brakes and rear dis brakes?

I ask because I swapped some 2003 disc brake parts onto my 1998 drum rear axle. I didn't change anything but the parts at the wheel. Distribution block did not get changed.

Both rear calipers are clamping the rotors much tighter than they should. After a quick test drive the pads were smoking, but the fronts were not hot at all. They rode as light as they were supposed to but the rears were clamping the rotors.

I'm wondering about distribution. Is there something about a drum brake system that requires more pressure to be held on the rear brakes that might differ from a disc setup that releases that pressure back into the system?

Please help me understand better...I need to fix this fast.

Thanks.

 

I would venture a guess that the rear wheel cylinders on drum brakes might have something to do with the pressures. Were there any 98's that came from the factory with rear discs? If they did I would check part numbers on the distribution blocks. Sorry, this is just a guess.

 

Yes when you swap from drums to disc in the rears you also need a new distrobution block. The reason being that the D block for the drums sends more pressure then the D block for discs. You need more pressure to stop with drums then you would with discs so your best be would be to hit a u pull it and grab the D block from one with disc in the rear

 

Okay, good info. Is this the block that is bolted to the top of the rear end housing, which the two rear lines connect to? Or is the distribution block up under the master near the ABS module, pump, and lines?

Thanks.

 

It would be the second one in line after the master cyclinder. It will have a single inlet line and two outlets that go to the front and rear brakes

 

Guess there is a difference, but you are cross posting: https://dodgeforum.com/forum/1st-gen...drum-axle.html

 

I have not had an issue with my swap. But then again I am mostly on manual brakes as my power booster leaks and needs replacing.

I'm replacing it when we get back from Cozumel on the 16th. This threads helps me out a lot as I will need to keep and eye on my rear discs after the booster is replaced. I might need to replace my D block then.

 

Sorry about the cross post. The issue drilled down to something much more specific and I needed a new set of eyes cruising through new threads that might react to one thing after having already read another.

I'll replace the distribution block tomorrow and go from there.

Thanks.

 

When you get it, post up the part number on the new d block please. Thanks!

 

Researched a bit today and running into more issues. My 1998 has a proportioning valve just next to the master cylinder. I assume this is where my problem is. The issue is that the 2003 doesn't have this proportioning valve next to the master. The lines all go from the master to the ABS control system.

The 2003 I sourced the rear disc parts from was a front ABS just like mine so I have been assuming that the rear brake system is not controlled by the ABS system.

However, if the 2003 doesn't have the proportioning valve then how would I swap part for part?

At this point I am wondering if I can somehow modify my proportioning valve in a way to relieve the pressure from the rear system...making it 1-1 of sorts.