Brake issue

[phillbus914]

I drove a bunch of friends around in the bus this past weekend and it developed a brake issue.

The brakes are hydrolic but have an electric back up incase the engine stalls it provides boost to be able to stop the bus. Well this electric motor kept running even with the key off & my foot off the brake. So I crawled under the bus and seen a vavle that was smoking and leaking brake fluid. I cut the power wire to the motor so it would stop running & now my brake lights are inop as well.

I think I'm going to try to replace that valve and reconnect everything and see where I'm at at that point.

I had an issue last winter with the brake pedal not fully comming back up after making a stop. I "fixed" that with a spring to pull the brake pedal back up and it has been working fine.

If anyone has any ideas that would be great but I think I'm going to replace that valve and see where I'm at.

[GoneCamping]

I had a Ford F800 Roll Back Wrecker equipped with the Hydra Boost that did this all the time. It turned out to be a relay would get stuck. We tried replaing it, but after a while the new relay would stick too. Got to the point that everytime it started doing that, I'd pop the hood open, and 'snap' the relay with my finger...gave it a good hard snap...the relay would kick off and the brakes would quit giving me fits!!

[phillbus914]

I got out my service parts catalog and looked up the part that was leaking. Turns out it is a brake stoplight switch, so I called my local Blue Bird Dealer & ordered the part for $71.

It makes since now though. This brake switch must provide the input to the back up motor. With the switch stuck on it kept the motor running all the time. When I looked under the bus to see why the motor was running I seen the switch smoking (probably overheating from being on for a few hours) I clipped the wires to it and then my brake lights didnt work.

They said I should see it in a few days, hopefully I will have time to put it on this weekend.

I will repost when I get it on.

[phillbus914]

Well the brake light switch I ordered showed up a few days after ordering it and looked nothing like what I needed. The switch I had go bad is a pressure activated switch that is mounted in a junction block in the brake line. What showed up was a manual activated switch.

I called the dealer & mailed him a diagram with the part # out of my parts catalog. So he ordered the part - shipped directly from bluebird to me for $98 (I figure diffrent price = diffrent part) I get the part a few days later and it's the same thing only now it's a kit with a bracket, wire harness ect... Still a manually activated switch.

I call him back, he calls bluebird and I guess they've had problems with that pressure switch leaking and now it is replaced with a manual switch. So I mounted it under the floor of the brake pedal so it contacts the brake pedal linkage.

Now to fix the fluid leak at the pressure switch... I go to Autozone and get a plug. Just a brass(?) fitting with a square head, screw it in. pump the brakes no leaks. Allright back in business! Now just gotta bleed the brakes.

I have my girlfriend pump the brakes with the engine running & I crawl under the bus and crack the 1st bleeder. Shockingly it comes loose and I bleed the rear brakes then on the the front. I get to the pass side front and she pumps the brakes and I see/hear fluid pissing from the other side just behind the front tire (not where I had just plugged it @ the old brake switch) I look and I have a rusted through brake line a few feet back from where I was working.

At this time I'm suppose to be getting ready to drive a bunch of friends around from their weading to the reception.. I run to napa "sorry we don't carry brake line that size" they did refer me to another shop in town that did, so I race over there get the line go back and try for hours to get the brake line fittings loose.

A few hours, 1 smashed knuckle & 1 chunk of rust in my left eyeball later I got it done. Bleed the brakes and test drive it and it seems like the brakes are better then they've ever been. This thing stops better than my 97 F150.

I missed my friends weeding & half of the reception, luckily another friend has a nice 5th wheel trailer and hauled the wedding party around in that, which kinda worked out better since I didn't have to drive them around all night... meaning I could have a good time

uggg what a crappy job that turned out to be, I'm glad it's over and that I was able to save the money by doing it myself.

[Ryan Grimm]

One suggestion I've heard repeatedly when you have hydraulic brakes......STOMP ON THEM before you buy to see if they burst, and plan on line replacements due to corrosion.

And someone on 'another' bus group hates Ford's Lucas-Girling brakes, says they're a pain in the ass...don't know myself, but I'm keeping my eyes peeled.

Glad the brake line failed before the trip! Gonna check all the rest of the lines now?

[phillbus914]

Yeah the other line that runs right next to this one is scachey at best... The rest look fine though. During my final test drive I stomped on them several times & no leaks.

Good advise on stomping on them when shopping for a bus.

Oh and a side note; those black plastic car ramps can hold a bus up. I was a little nervous being under the bus being held by a plastic ramp but it worked out fine.



Their rated for 12,000 lbs GVW but held the front drivers side of my bus up with no problem. I got in the bus and jumped around - rocking the weight on the ramp 1st & it held so I figured it would be good. I wasnt in a spot where I had to have a ramp but it made it a lot eaiser.