'91 Flair brake warning light

[Alex_KN0I]

I did search for this and had no luck finding anything...

Late last summer, I picked up a '91 30' Flair. It run spectacularly, Banks headers and exhaust, and transmission works perfectly. We took it on a couple of longer drives (3-4 hours each), and as time went on, I noticed that the brake warning light in the middle of the dash started illuminating more and more often. And, it seems to be based on engine speed. When the engine is idling, the lamp is off. As we start revving up, the lamp starts flickering and eventually will stay lit when the RPMs are up. When it upshifts, the lamp goes out momentarily, until the RPMs start climbing again. So, it seems to be related to engine vacuum.

The brake fluid level is normal, I don't seem to be losing any. The coach does pull to the right quite heavily initially on braking, but that seems to normalize after a few braking maneuvers but returns after a longer period of non-use, so I plan on going through all four corners in the spring. I also want to look at the parking brake, as it seems to not be working properly (and that seems to be a common issue on these chassis). But I just thought I'd throw this out to the group before starting on the work to see if there's anything else I should be checking on while working on the brakes.

Also looking for a source for the plastic exterior doors for the electrical and propane locations. REV doesn't seem to carry them. I've looked at 3 or four "local" RV dealers, and none of them have them. It'd be great if I didn't have to custom-make new doors...

Thanks in advance all!

Alex

 

[Alex_KN0I]

BTW, it's a GM P30 chassis. Anyone have any guesses on why the brake lamp acts the way it does?

 

[Kevin D Pem]

Brake vs. Abs? Could be as simple as adjusting the sw. For emergency brake.

 

[Alex_KN0I]

I don't think there's any ABS on that rig. The parking brake is a possibility, though the change based on vacuum/engine speeed doesn't really jive with that.

 

[Kevin D Pem]

I don't think there's any ABS on that rig. The parking brake is a possibility, though the change based on vacuum/engine speeed doesn't really jive with that.

But bouncing down the road does.

Catching brake may also indicate worn pads and they may have a sensor. That is speculation. As for vacuum leak! That would cause a check engine light, not a brake light.

Think the brake light is to let you know you need to release the emergency brake!!!

 

[Kevin D Pem]

Oh yah! My bago was on a 96' P30, and if memory serves the E brake was what that light was for. That useless drum on the drive shaft was not worth it's weight in dog due due.

 

[GypsyR]

Not an expert on 1991 GM chassis but on many older vehicles (without ABS) the brake warning light does triple duty. First it tells you the parking brake is applied. The little switch on the parking brake would be the first thing I'd look at. Sometimes the switch is fine, just the return spring is no longer pulling the pedal back up far enough to close the switch anymore for some reason. Usually pretty easy to fiddle with and see what's up. If you can gets eyes on the situation.
Also on some vehicles there is a brake fluid level sensor on the side of the fluid reservoir. Those can be problematic as they get old. You can tell easily if you have one or not by seeing if there's a plug with two wires anywhere around the brake master cylinder and reservoir.
Lastly there's a brake bias (or proportioning) valve. Where all the brakes connect and there will be a single wire switch. It's purpose is to illuminate is brake pressure is suddenly lost in the front OR the rear brakes. When that happens, like say a right rear wheel cylinder blew out then the rear brakes would be rendered non-functional by the valve, the light would come on, and you'd still have the front brakes to stop with. Or vice-versa. The light would stay on constantly until the issue was corrected. The switch tends to be on or off, no flickering.

A last remote possibility might be an issue with the bulb socket in the dash or another dash wiring issue. Such issue would normally cause the light to not work at all but weird stuff happens sometimes.