Brake Warning Lights


We have a 2008 Georgetown model 373 Class A on a 2007 Ford F53 chassis with a V-10 engine. About half the time the parking brake light and brake reserve system light come on, sometimes for a short time, and other times for an extended length of time. Last fall they were on for 500 miles then off for the next 3,000 miles. It seems rough roads and/or bumps turn them on or off.

Harley Beall | Sioux City, Iowa

Sometimes the parking brake pedal switch may be faulty or out of adjustment. With the ignition switch on, cycle the parking brake pedal up and down several times and see if the light stays on when it shouldn’t. The next thing you should check is the brake fluid level. If it is not near the maximum level, top it off with the brake fluid recommended by Ford. The brake fluid level drops as brake pads wear and the caliper pistons move outward, so if it’s been a while, the brakes should be checked for wear and while you’re at it, the sliding components should have brake lube applied to prevent sticking.

A low fluid level can also result from a loss of fluid anywhere in the system, including out the back of the master cylinder bore, so have that checked, too. If it has been more than two years since the fluid was flushed and changed and the system bled, a qualified technician should do this. If no problems are found the master cylinder fluid level sensor may be faulty.

— Ken Freund

Man smiling and standing next to truck driver side

Have a technical question about your RV? Send them to [email protected].


  1. Having same problem with as was written in 2012 concerning the Brake Light and Brake Reserve warning System Light comes off and we spent 500.00 to change the sensor which did not help the problem. I assume this is a Ford recall problem as it is still happening. We want to feel safe driving our Motorhome with the Ford Chassis. Please what is the problem and what is Ford doing to repair the problem. Thank you, Sandra Hardin

  2. I’d like to add my two cents to the dreaded Brake Fluid Level Low message and the stubborn Brake Warning light on the instrument cluster that many folks seem to experience on the Ford F53 Motorhome Chassis. We have a 2017 Holiday Rambler Vacationer M-35P with less than 9,000 miles on it. It has the Hydromax brake system on it. About a month ago the Brake Fluid Level Low message and the Brake Warning indicator light popped up on the instrument cluster. Of all the dreaded messages to get. I immediately checked the brake fluid reservoir. It was right on the max fill line. I suspected a faulty brake differential pressure switch. First I did a scan with a basic scan tool. It showed no Diagnostic Trouble Codes (DTCs) at all. In desperation, and hoping I wouldn’t have to resort to taking it to the shop, I purchased the Ford service manual – all 5,207 pages of it, complete with wiring diagrams and pinpoint troubleshooting procedures. Every test showed all components were good. So, being the never-say-die-pig-headed-DIY-shade-tree mechanic that I am, I purchased a professional scan tool – Launch X431 V+ – for about $1,200 and proceeded to scan every system in the onboard computers. (Did you know the OBD even tracks engine hours)? But I digress. Bottom line, once again, my scan tool showed absolutely no DTCs. Now, at this point, and after all the hours and resources I spent troubleshooting this one little issue, I felt like sitting in the motorhome and crying. Then, as if God himself had dropped the thought into my mind, I decided to go back under the hood and remove the brake fluid pressure differential switch one last time and take a look. The switch was immaculate. I had cleaned it earlier with contact cleaner. But this time as I was sliding the spring loaded switch contact back and forth in the switch housing, it dawned on me that the tip of the spring loaded contact needed to be in good contact with the cast iron base of the brake fluid reservoir that it was threaded into in order to close that brake fluid level circuit. I immediately grabbed the can of contact cleaner, sprayed it into the threaded hole that the switch threaded into. I then took a Q-tip, inserted it into the hole, and swabbed out the rusted corrosion. I re-installed the switch, went inside the motorhome, turned on the ignition switch, and like magic, no Brake Fluid Level Low message and no Brake Warning light. Problem solved. Lesson learned. Hope this helps anyone else with a similar issue. Safe travels.

  3. I have a 2007 F53 Class A with a cruise control not working. I have purchased the Cruise Control Cutoff Switch from Ford, but cannot locate it in or around the master cylinder. Please advise, driving me crazy.


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