I'm starting get really upset... my rear brakes are still giving me issues. History... Back in January I had the rear cylinders swapped out to the Chevy 1 ton and the rear proportioning valve bypass. Also had new shoes installed. All seemed well up until about a month ago. My work is seasonal so things picked up a month ago.. so more driving and braking began. It seems the warmer the brakes (fluid?) get.. the worse they get. Recently had the rear drums turned, new spring kit and adjusters installed. The shudder is back and progressively getting worse each day.. and again the more use they see throughout the day.. the worse the shudder. They also become extremely touchy (grabby) and the antilock is kicking in kind of easily. 

 

I have not read any negative feedback on the larger cylinder upgrade or the proportioning valve bypass... So.. kind of stumped here. 

 

I brought it to my mechanic and he test drove... when he came back he was shocked at how grabby, shuddery <--- for lack of a better word and how easily the antilock kicked in. 

 

He suggested to go back to the stock sized cylinders to see if that helps. 

 

Could the front proportioning valve be the problem? How do you tell.. or test?  

 

What else can it be?

If you want to disable the abs just pull the fuse or relay. The brake/abs lights will be on but the speedo will still work. 

From what I can tell all the rear wheel abs does is cut line pressure to the rear brakes if it detects a slip. Trying to stop on ice the front tires will lock up while the rear tires are free wheeling. Now pull the abs fuse and all 4 tires lock up. 

With that said obviously the abs module can control rear braking pressure. I suppose if the module is having problems it could be pulsating rear brake pressure giving you the shuddering.  

Edited May 5, 20168 yr by Buzzinhalfdozen

Okay.. like I said.. I'm having drums turned again.. new Napa premium shoes and a flush. If I still have the problem after this I will unhook the ABS. 

I believe it's a 4 wire plug that I did have unplugged but it did nit effect my Speedo.. just had brake light and ABS light come on. If that doesnt work I'm putting in new master cylinder... then new proportion valve. Ugh

Edited May 5, 20168 yr by dodgedieselnewbie

DDN,

 

One thing I thought of over coffee, make sure you put the primary (smaller braking surface) shoe forward.  This makes a HUGE difference.  (the self actuating nature of the bendix brakes depend on this to NOT over apply)

 

I would go combination valve before MC.  See the FSM page I have attached.  It tries to control early pressure balance (see metering function).

 

Brake pressure testing is not that expensive (though I want the killer OTC kit at 500 bones...)  It looks like Jegs/summit have kits at the 50 buck mark.  Just check your bleeder screw size to make sure the adapter is in the kit. 

 

Good Luck!

2001 FSM Ram 5-9.pdf

Yes.. smaller shoes are and have been forward. Thanks a million for every reply. Will report back later... fingers crossed :-)

 

Edit

BTW.. I am still having an issue with my front right brake putting out twice the brake dust over the left.. and does have a slight pull to the right but not all the time. It's nit enough to pull me off the road but does turn the wheel a little.  Is there any correlation between the two issues?

Edited May 5, 20168 yr by dodgedieselnewbie

Well.. system was bled and was clean as a whistle. Drums were cut and very little was taken off. New Napa Ultra Premium shoes installed... cha-ching

and............................................... ...........

I don't want to get too excited yet... but... after an hour and twenty minute drive all over Carroll County (man oh man.. lots of cops out there!)... nothing. So far.. so good. Fingers crossed! So.. my thought right now.. is bad/crap shoes. Time will tell...

I hope that was all it was!!!!

 

Hopefully the rear brake problem is behind you. (pun intended lol)

 

Focus on that front.  The Right Front seems to be very susceptible to the collapsed hose thing, and therefore not relieving the pressure on the caliper.  I have had this failure and 2 Weekends ago one of my venture crew members went through that too... and due to not listening, he ended up with having to install a new rotor, caliper, wheel bearing assembly and drive shaft. (messed up the threads on threads on the drive axle.... those axles are not cheap btw...)

I hope so too... and beginning to believe so after driving all over kingdom come today.. with not a hint of a problem. I only felt the front pull once today.. I replaced the front hoses a couple of weeks ago. I think it's in one of the calipers. Maybe the driver's side is the one that's not right. If it gets worse.. I'll replace both. 

 

Thanks again!!!