left wheel locks up, feels hot.

[Deb Kirkpatrick]

1997 Dodge Ram Conversion Van 1500, with ABS brake system. The left front wheel locks up. The brake piston was locked and damaged the rotor/hub assembly. I replaced both front rotor/hub assemblies, new calipers and brake pads. Also, new inner and outer wheel bearings, and grease seals on both sides. I still have the problem!!! While driving the van pulls to the right. When braking, it pulls to the left. The passenger side front wheel drags and starts to lock up and the wheel is very hot to touch. The drivers side is not hot. Could this be the Master Cylinder? The Controller Anti-lock Brake (CAB)/Hydraulic Control Unit (HCU)? The Haynes manual says the CAB/HCU controls each front brake independently to modulate brake fluid pressure and control wheel lock-up. In the trouble shooting section it says a Master cylinder piston could be siezed in the bore with the symptoms of the brakes dragging or wheels being very hot. I'm thinking more to toward the CAB/HCU since it only happens on one side. Does anyone have any experince with this? This is getting expensive...

[alloro]

Replace both front brake hoses and then bleed the system.

[Mopar_Stev]

Originally Posted by alloro

Replace both front brake hoses and then bleed the system.

Exactly. I had done just this very thing this week.

I had replaced; calipers, pads, bleed lines, inner and outer bearings, rear self adjusters with no success fixing the sharp pull to the left while braking or the hot locking caliper issue until the hoses were changed. BUT watch out changing those hoses. Sure, the job looks simple, BUT ...

Here's a short write up I did in the other Dodge forum ...

Got the brakes working soooooo good right now. The best they have been in 2 years!

Got the OEM Bendix front hoses from Rockauto.com
Bendix 78873 and 78874 for the HD 8-lug wheels from 1998-2003.
The Bosch and Denso didn't look like the OEM style and were more money. I could have done the Raybestos too, but Bendix has been in the brake business with a good brand name for several decades.

Learned a few things while changing the hoses out.

- Each interface plate that mounts to the frame rails is held by a bolt. No matter how much that bolt is soaked in penetrating fluid, the head will just snap off. ERRRRR. LOL This explains why the original and the Bendix has a backup hole in the plate. BUT, you must drill the new hole in the frame. Just drill a slightly under sized hole to the hole that is in the plate. The metal is a bit hardened on the frame and may take some time to get through. I personally recommend a high speed drill. 8 mins and you'll have a hole.

- Soak, soak and soak again the hard line fitting(s) going to the junction blocks. (I used Seafoam DEEP CREEP). These fittings are 12mm open wrench size. If they do loosen and unscrew from the block, do each one a little then still WATCH OUT. The hard line will twist on the stubborn ones. If this happens.... STOP turning the fitting, else the hard line will snap !!!! You will then need to undo the mounting bolt holding the plate and let the head snaps off.

- If you have lines that may twist, fret not! You can still get the job done without snapping the line. Just undo the bolt that is held in the middle of the hose- line to the upper suspension. Next undo the bolt to the caliper and save the copper washers. Now, feed the hose and line to the front area. Rather than twist the fitting and snap the hard line, rotate the entire old hose-line to get the hose-line off. You will need a 17mm open end wrench to turn the block fittings and the 12mm to hold still the hard line fittings. (if the plate gets in the way of the hard line, carefully bend the hard-line a little out of the way. This is somewhat tricky on the drivers side since there are TWO fittings. My good chance was that one wasn't frozen. With the NEW hose-line, just rotate it onto the hard line fitting until it stops and seats. Next, position all of the hardware where it need to mount. My passenger side actually seated about 60 degrees off from horizontal to have the plate lay flat. I had to carefully turn the plate and adjust the hard-line to make it all work. Nothing snapped nor was really stressed.

- I strongly recommend getting TWO large bottles of DOT 3 brake fluid. When rotating the old hard-line, be very careful not to drip on the caliper and brake shoes. Also avoid brake fluid on the vehicle paint since the paint will dissolve on contact. :WHT:

For something that looks easy to do in 15 mins, think again. Especially if there is rust involved. hahahaha 2-1/2 hours on the driver side since I snapped off the bolt first without thinking of loosening the hard-line fittings to the bolts. :ugh I had to find the metric open end wrenches and a vice-grip tool. Knowing the issues, the passenger side took less than an hour.

All of the hard work payed off though. The van no longer pulls hard to the left while braking. Actually, it has a little bias to the right. I need to check the driver's rear self adjuster to get the balance to perfect center now. I'll have to check to see if the rear hoses to the drums need replacing next.

I can also lock up the wheels and the rear ABS actually now kicks in.

Hopefully, my dealings with this will help others to know what to look out for and to tackle the job easier.