2nd Gen Non-Engine/Transmission front brake nightmare,please help!!!

[UhhhDawson]

happy new year fellers. ok, a few weeks ago i had the valve body replaced on my 98 12v qc auto 4x4 w 150k, no big deal. im driving home enjoying the new valve body when i get out and smell burnt clutch. i realize the front wheels are really hot and that the calipers are sticking. the brake pedal also feels really stiff and has almost no travel. replaced both front calipers with brand new ones from mopar, after cruising for a little bit they start sticking again. changed both front brake hoses, front wheels still feel hot and pedal stiff with no travel. completely bled the brakes after the new calipers and new hoses but still no improvement. ive had the truck since july and it has given me no problems and then they just starting sticking out of no where and my fuel mileage is way down and the truck isnt fun to drive anymore. am i missing something obvious that could be causing them to keep locking up? thanks!!!!!!!!!

 

[NVR FNSH]

Sounds like it may be a problem with the check valve in the master cylinder or a vacuum booster problem of some sort. If it is a vacuum booster problem I would expect the rear brakes to be dragging unless the shoes are so far out of adjustment that they won't contact the drum.



Brian

 

[NHays]

These trucks don't use vacuum boosters, they use hydraulic fluid from the power steering system. Sounds like you need a master cylinder assembly. There is high pressure hydraulic oil leaking past somewhere causing the brakes to drag.

 

[San Felipe Bob]

what a drag

Check out this handy video.

It shows how the tire should spin.



http://www.youtube.com/watch?v=RGHd5-j2TQk



If your tires do not spin freely the calipers are dragging.

You'll need to find out why they are dragging.

It sure sounds like you need to look at the Master cylinder or something in the ABS system.



Did you follow proper installation methods when installing the calipers?

Avoid pushing old fluid back into the Master cylinder by cracking the caliper bleeders when compressing the caliper pistons.



SFB

 

[NVR FNSH]

These trucks don't use vacuum boosters, they use hydraulic fluid from the power steering system. Sounds like you need a master cylinder assembly. There is high pressure hydraulic oil leaking past somewhere causing the brakes to drag.

I thought my dad's '96 12V uses a vacuum pump & booster - I may be wrong.



Brian

 

[NHays]

Well shoot, if your dad had a vacuum booster I don't doubt it, I though all the diesel trucks had a hydraulic assist braking system, at least all the ones I have worked on did. But I have only worked on either HD 2500 or 3500. My 2500 has a hydraulic system on it, I just never realized that they made these trucks with a vacuum booster. I have to retract my earlier statement, and I am sorry that I have made this incorrect statement. Also, in further research I have found that Dodge even had a problem with the vacuum boosters in that year of truck, " APRIL 28 1997, 58,000 vehicles recalled



1996 DODGE RAM -- Vehicle description: Pickup trucks equipped with diesel engines. The engine driven vacuum pump can allow engine oil into the vacuum hoses due to the absence of an internal check valve. The oil can cause the hose to deteriorate and partially collapse, reducing the vacuum supply to the brake booster.



Reduced power brake assist can result increasing the risk of a vehicle crash.



Dealers will add a vacuum pump check valve to the vacuum pump. In addition, the vacuum hose connected to the vacuum pump will be replaced with a hose that is engine oil resistant. For detailed information & supporting documents, see the official NHTSA page concerning recall #97V068000. "



Although this is an unrelated instance or problem, it just backs up the fact that I am wrong... ... ... In any case however, I went through the same front brake dragging on my truck about a year ago. I found that it has a leaky proportion valve that powered the hydraulic function on the master cylinder, or something fairly close to that, anyways, I replaced the master cylinder and problem solved. Oo.

 

[NHays]

But, I do think that the truck at the beginning of this thread has a hydraulic system in it.