Hey all,

I've been searching the threads trying to find one that the same problems as me but couldn't......

So, the other week I was going down a dirt road and my Parking Brake indicator light in the dash lit up and has stayed in since then, just the Parking Brake light, not the ABS or anything else. Now here's the weird part to me, if I push on the brake pedal as if at a stop light and hold it for 2 seconds, the light goes out. Sometimes until I release the brake, or sometimes comes back on after about 20 seconds even with the pedal still depressed. I replaced the master cylinder because it had been going for some time now, and put new fluid in the whole system. Bled the front and back completely until just new fluid came out, used about 3 containers of brake fluid...... The brakes still work great, even better now with the new master cylinder, but its annoying having that red light on all the time.

So I am really lost as to what it can be, I'm thinking it could be a sensor or something that isn't picking up the hydraulic pressure until it is pressurized by depressing the pedal. I tried resetting the computers by turning the key to "on" and pulled the battery, stepped on the brake for 30 seconds and it didn't clear the light. The CEL is on, but it isn't throwing any codes I can tell that relate to the braking system.

Any help or suggestions would be really appreciated.

- Josh

p.s. I work shift work, so it may take me a day or two too get back to you guys, but I will eventually.

 

First and foremost, see what codes are setting the CEL. And parking brake has no connecction to master cylinder. It is a cable system to rear wheels. There should be a switch somewhere on the pedal assembly. Haven't looked at it though, just know it has to have one.

 

There aren't any brake specific codes you can read. If you have 4wal, you need to the expensive scanner to get the ability.

If your brake lite is on, and goes off when you step on the pedal, bleed your brakes again. You DID bench bleed the master before installing it, right?

 

That's why I said he needs to check codes for CEL. OP started out about parking brake light, which is separate from CEL, so he has more than one problem. Brake light may have indicated hyd brake probelm and no parking brake probelm - but still has CEL issues.

 

Quite true. And ABS codes won't set the CEL in any event. (aside from output speed sensor code, and he didn't mention that his speedo was going nuts.)

 

Ok, so from the top, as far as i can tell the CEL is throwing codes: 12,43,21, and 55, 12 and 55 being normal. And according to this site http://dodgeram.info/Engine-Gas/OBDI/pcm_fault_code.htm 21 is regarding the O2 sensor which makes sense to me because I am in dire need of a new plenum plate and gasket, but thats a whole other story. Second, 43..... I am actually not to sure what that entails :| if someone could shed some light on that it would be great, otherwise its all good!

And yes I know of the brake pedal switch you mentioned, I have looked at that and all the wires seem to be plugged in correctly. Although I did recently install an electric brake controller about 2 months ago, and I did splice into the wire that sends signal to light up the brake lights in the back so when just the controller is used with out the brake pedal the back brake lights illuminate. But I don't think that could be the source of the problem, the (I'm not 100% sure if i am referring to it correctly but) Parking Brake Indicator light in the dash lite up when I was going down a dirt road about a month and a half after the controller was installed. I could be wrong tho.

My truck only has RWAL, I checked after reading some threads on here and I don't see any wires going to the front axles/diff of the truck only the rear. And yes I did bench bleed the master cylinder before install, I was actually surprised at how long it took. And just to clarify, I replaced the master cylinder the day after the dash light came on, I thought it could have been the root of the problem.

The speedo is working properly, other than being off because of the size of my tires, going to try to fix that when I find someone with the proper scanner so I can change the tire size in the computer. And my brakes work great, the rear lights lite up properly, and the actual cable parking brake does work when the pedal is pushed down. On that note, when you engage the parking brake there is a difference in how bright the Parking Brake indicator light in the dash goes. I can explain it this way, when the truck is on and idling the P.B. dash light is on but is dim, and when the actual cable parking brake is pushed/engaged the P.B. indicator light goes brighter telling me that the P.B. is on.

I really hope I didn't confuse the $**t out of anyone. In any event Thank You to you two guys for helping me out thus far.

I'll be checking back in in about 8-9 hours, thanks again!

 

Ok, I suspect your brake lite is due to the proportioning valve (also a form of safety switch, if pressure is low on one circuit or the other, it will attempt to close it off. This can sometimes happen while bleeding brakes.) So, try this:

Grab a friend, park 'em in the drivers seat, have them pump up the brakes, and then you crack open one of the rear bleeders. When the pedal hits the floor, close the bleeder, and pump the brakes back up. Does the light stay off when you let off the pedal?

If it doesn't, try the same trick on one of the front brakes.

 

There is also a switch on the back of the P brake lever. And that wire runs to the instrument panel and daytime running lamp module. Since you are in Canada you have one. And it seems to be a problem part for other issues.

 

Alright, thanks guys ill check/try those tomorrow and let you know how it goes. I gotta go in for my last midnight shift tonight

- Josh