What causes the dash brake light to come on?

[Clyde9]

From: Afubar69  (Original Message)    
Sent: 3/21/2006 12:54 PM

While trying to get the Green Winnie up and running for an April trip, I noticed that the Brake light on the dash is on.  Tried setting and releasing the E-Brake a couple of times and pumping the floor pedal.

The Winnie was not stored with the E-Brake on.  She started right up, first hit of the key, no pumping of gas pedal (now I know what that strange knob on the floor was, lol).  Replaces Transmission Dipstick with on that I made (shortened a longer one that I got on Evilbay).

Any Ideas, also, what else should I be checking out (besides tire pressure) to ensure that the old girl is ready to go?

Thanks



From: Elandan2    
Sent: 3/21/2006 1:43 PM

The brake light comes on when there is a differential in pressure between the front and rear brake systems when the brake is applied.  The fact that the light is on indicates there is a problem with the brakes.  Either you have developed a leak or the master cylinder has worn out and is allowing pressure to leak by the seals inside.  DO NOT go anywhere until you have isolated and fixed the problem.  The light does not have anything to do with the parking brake.  Hope it is a simple problem.  Rick



From: denisondc   
Sent: 3/22/2006 6:45 AM

And since 1/2 of the brake system has a problem, the other half being equally old probably needs the same attention.
If the leak is very small you might not be able to see any fluid streaking down the inner sidewall of a tire; yet. So at the first occurrence of the warning light coming on, the real problem can be hard to find. It could be a fluid leak. It could be the self adjusters on the rear brakes are not working (not uncommon) and the brake shoes have worn enough that the amount of fluid needed to push the shoes out against the drums is enough to trip the warning light. It could be a leak from the master cylinder - which can be hard to see if the fluid leaks -into- the booster instead of onto the ground. I believe yours has the booster mounted right against the master cylinder.
I presume yours has disc brakes in front. They can leak fluid, but if you have had weather below freezing, air can get sucked into the piston on cold nights. This can cause the warning light to come on, due to the air bubble inside the caliper bore. If this is the problem, you would see air coming out when you bleed the front brakes, on one side anyway. Bleeding the air out would eliminate the warning light coming on until the next cold weather, but … the real solution would be to rebuild the calipers.
Before any trip I look into the master cylinder reservoir, to see if the fluid level in both chambers the same as when I looked the last time. I drilled a 2" hole through the floor to be able to do this. The hole is just to the left and behind the driver's heel on the gas pedal. I do this about a week before the trip, to give me time to fix any situation I find.
My Winny is 34 years old, and we have had it long enough to have replaced almost all parts of the brake system except the metal brake lines. I keep a list of the date and mileage when the various parts were replaced or last examined: Because as old as our Winny is, ALL of the parts of the brake system have either been replaced, or are Very suspect. And my knees even have some arthritus!
Let us know what it turns out to be.

Other things to look at; Tire pressures including the spare. Coolant level, power steering fluid level, you already checked the tranny fluid I presume. I grease mine myself, its has 22 zeerk fittings, and I have to jack up the front axle to properly grease the kingpins. While I am underneath I check the differential fluid. I start it up with the engine cover off, and I watch for fuel leaks, sparks, smoke and flame. If I didn’t know how old the belts and hoses were I would inspect them for signs of age. I fill and flush the coach water system,as much to see if there are any new leaks as to clean out the old water. I remove the propane tanks and weigh them to see how much they have inside.


And I would make sure I had some extra fuel filters, along with my tools of course.



From: Afubar69   
Sent: 4/18/2006 3:45 PM

Took the Green Winnie in to a Ford Dealership (I know, but the service guy was recommended by an RV place here) and had the brakes checked out.  They bleed the brakes and all is well, said I had a very tiny leak in the MC but that he thought driving her would more than likely solve that problem.

I've gone over the rest of her and she appears to be ready to take off this weekend, sure was painful to fill the gas tanks, but decided that if I was gonna have the old girl, I was gonna take her out more.

Will let you know how she does.

Thanks.



From: denisondc   
Sent: 4/19/2006 7:20 AM

I agree that use of the brakes will help keep them fit. But.. I would check the fluid levels in the master cylinder reservoir from time to time anyway.

Happy Traveling.....