Forum Discussion

olfarmer's avatar
olfarmer
Explorer II
Sep 08, 2019

Brake problem

Just drove our old 2001 Winnebago Brave that has 32,xxx miles on it from N.C. Iowa to Kalispell, Mt. about 1400 miles. Every thing worked great until I pulled into the campground we had reservations at. Brakes worked good all of the way and even when I stopped at the office to register. As I drove slowly to our sight the brake pedal went almost to the floor, the brakes did slow me down and stop me but I don't think I could have locked them up. I got it backed in the site and let everything cool off and it feels like the pedal has come back up. I looked underneath and at the wheels and no signs of a fluid leak and the master cylinder is full. So, is it a failing master cylinder, boiling moisture in the fluid or something else? I did hit the brakes real hard about 70 miles back when a dog ran out in front of me and the wife said the tires were squealing the brakes were working good then so any ideas what might be wrong? I feel lucky that they didn't cause any problems until we were about stopped! We just drove through a lot of mountain grades but I didn't ride them, I shifted down for long down grades.

39 Replies

  • crawford wrote:
    7.4 gas Work Horse Chassis didn't they have a recall ?


    I believe the OP's rig is on a P-series chassis. Not having that chassis, I'm not aware of a brake recall on that chassis. The brake recall I DO remember was on the W-22 chassis with the 8.1L. It might have also applied to the W20, but I'm not sure on that.

    ~Rick
  • If the brakes return to close to normal after things cool off, then there is nothing wrong with your master cylinder.
  • olfarmer wrote:
    Thanks for the replies. Those are the only reasons that I could think of too. The fluid has never been flushed to my knowledge. Wouldn't a failing master cylinder have leakage and fluid loss? Or, could the fluid pass by the piston and not leak out?
    Ed

    Brake fluid should be changed every 2 - 3 years, with at least DOT 4 and 5.1 would be even better, but may be hard to find.
    Boiling point for new fluid is over 400F and with you obviously boiling yours, it was probably lucky to have been 212F.
    Also reeducate yourself on mountain descents and if you're using the brakes much at all, going down, you need to be in low gear.
  • Thanks for the replies. Those are the only reasons that I could think of too. The fluid has never been flushed to my knowledge. Wouldn't a failing master cylinder have leakage and fluid loss? Or, could the fluid pass by the piston and not leak out?
    Ed
  • Sounds like your master cylinder might be failing.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Happened to me on 12/18/2104 with my car (yes I can even remember when)
    I "Spiked" the brakes when a "Ten T" pulled out in front of me.. I missed him (that is 1 D 10 T delete spaces and read what you see)

    Well when I got home.. To the floor but thanks to the modern dual brake system I still had brakes... Blown cylinder.

    Made it to the local shop. Got cylinder replaced and then back Home grab the cheesecake I'd made for the pot luck and off to Cowboy Church where I was the Opening act for Trinity River Band (I sang Paul Stokey's Christmas Dinner) which is why I can remember the date. only time I've soloed.
  • I'm going to guess that your brake fluid had gotten hot during the drive to the campsite and what you experienced was the water in the fluid actually started to boil. If the pedal is up after things have cooled down, water in your brake fluid is the cause of your problem. It is recommended that your brake fluid be FLUSHED and changed every few years. Having your brake fluid flushed is NOT the same as just bleeding the brakes. On my coach it takes about 3 quarts of fluid to completely change all of the fluid in the calipers, the master cylinder, and all of the brake lines. Make sure that the mechanic also knows how to get the air out of your ABS(anti-lock brake system) when he is finished.