Engine/Transmission (1994 - 1998) 1 ton rear cylinders

[SRehberg]

Somehow I've run into a problem. I did the easy change out of the 2500 rear wheel cylinders to the 3500 larger ones. No problem. Took the hand held vacuum pump to bleed them, went o. k. Kept the brake fluid up as well. Fired the truck up and here comes the ABS light and the Brake light saying something is amiss! The truck brakes o. k. and seems to roll o. k. , so what happened? I used the trick of rotating the drums and hitting the brakes with the rear end lifted and tires removed, but that seemed to go fine. A clunking noise each time I hit the brakes to break the drums loose, but nothing eventful. Does this do damage to something?



Any ideas?

 

[illflem]

I know on my '95 if the brake warning lights go on they stay on for 50 on/off cycles of the key even if nothing is wrong. DC really wants to make sure your brakes will work. The fluid level may have gone too low while you were bleeding and triggered the warning. I've also heard that sometimes the low fluid level float switch will stick if the level goes too low and needs to be "helped"up. Don't know what else you could have done wrong.



I just pulled the ABS relay to see what it's like without ABS and the lights stayed on even after replacing it. I was positive nothing was wrong with the system. Disconnecting the battery for a whole day didn't make any difference. I was tired of the lights and about ready to pull out the bulbs when they finally went off after a couple weeks.

 

[SRehberg]

illflem, thanks for the information about the ABS. I don't understand about the float you mentioned though, is this inside the ABS unit or? I went back out to the truck and started it again, (mad at myself for inflicting something) the ABS light went out, but the red Brake light still remains on. Checking the manual, it states it comes on with a pressure differential between circuits, so possibly there's air. I know one time the front chamber was low, down a little bit from "min" but still fluid. I don't know if it could have sucked air or not. I checked the computer for codes, and nothing but "42" came up with the flashing light method.



I adjusted the brakes until they just "tick" when rotating, so I don't see a problem there, and the emergency was never touched.



Never a dull moment!

 

[illflem]

42 = ASD control circuit indicates an open or shorted circuit condition. ASD = auto shutdown.



I don't see how you could suck air if the level never went below min, plus the brakes would be spongy. I've never looked for the float switch but assume it's in the reservoir with a couple of wires going to it. Should be easy to find and see if it's stuck down. Other than that all I can say is good luck and call Sam if the problem persists.

 

[SRehberg]

illflem, I'll have to look for the float, as I'm not familiar with it. I e-mailed Sam and he is going to call; he sure seems like a heck of a nice guy! Thanks for all the help, I'll post whatever the problem is or was.

 

[53 Willys]

I have not looked to see if the Dodge brakes are like this but--- The brake warning light is controlled by a switch in the proporsioning (sp) valve. When a line is broken the fluid pushes the switch off center and the light comes on. By vacuum bleeding the rears you drew fluid fast enuff to pull the switch off center. There is a method in the manual for correcting this or it may recenter on its own.

 

[bighammer]

I wonder if the different cylinders fake out the proportioning valve and keep the sensor off center?



Just a thought (not necessarily a good one )

 

[illflem]

Originally posted by 53 Willys

By vacuum bleeding the rears you drew fluid fast enuff to pull the switch off center. There is a method in the manual for correcting this or it may recenter on its own.

Forgot about that one. The trick to recentering the switch is to slam on the brakes fast and hard several times, engine running truck not moving.

 

[SRehberg]

I'm back to square one. Took the truck for a ride around the block, hitting the brakes fairly firmly, and nothing changed other than the ABS light comes on again. Sitting still, engine off, the ABS light goes off, but the red Brake light stays on all the time. With the truck running, I get both lights on.



I re-bled the rear cylinders, and not one bubble came out, so that wasn't it. I'm going to re-pull the wheels starting with the drivers side, to see if something is whacko. I hope the drums come off easier this time, I reinstalled them with some never seize on the hub, so hopefully they wouldn't rust tight.



By the way, the rear cylinders are Raymold... . I think they must be imported and a copy of Raybestos. I can't see how that could be problem, as long as they hold pressure.

 

[SRehberg]

Well, I think I'm in line for the "dumb as* award". I pulled the wheel off the drivers side, and all was fine, but what caught my eye was the position of the spreader bar for the emergency brake. This one was fine, but I suspected the one on the other side. When I originally did the cylinders, the shoes have to be spread apart some, the bar fell out. No big deal, right? I installed it back like I have on all my other brakes, with the offset OUT. Big mistake; on these the offset goes IN. I knew I was right, so I didn't check the manual. I had even forgotten about it when posting, as I had felt everything was fine.



Bottom line is, hitting the brakes once after turning the bar around, all the idiot (smarter than I was) lights went out!



I want to thank everyone for the help; this is one GREAT site for getting the correct and accurate info on these trucks.



I am now ready for the lashing I so rightly deserve.

 

[illflem]

"I am now ready for the lashing I so rightly deserve. "



Always do one side at a time so you can see what it's supposed to look like.