My brake lights (as well as the brake telltale) stay on. I assume it is the brake light switch being bad or just stuck). Is it on the brake valve? By the way, I did try pulling up on the pedal, but it didn't help.
Another question-- Although the air system seems to be fine, it seems to me that the system loses air rather quickly if I am maneuvering through something like a multi-stop U-turn. Any suggestions there? Thanks
This may sound stupid, it is late here, but my brake lights are on whenever I set the parking brake, which is whenever I'm not in the driver's seat. Is that the case? Or are you leaving it running in nuetral with the parking brake off? That would be the only way I can check mine unless I send the DW back there, which is what we do before hitting the road.
Just a thought and probably way off base,
Will :)
One other thing, the brake light switch on mine is a pressure valve in the air line up front. I know because I had to replace it once.
Yes, the brake lights and telltale do go on when either the parking brake or service brake is applied. This is happening when both are not being applied. I, of course, knew that the telltale was on while driving. I did have to go out and look in the back with both brakes off to verify that the brake lights were on also. To be safe, I put it in first gear so I could catch the bus once I had checked.
Quote from: Lin on January 05, 2014, 08:55:00 PM
I did have to go out and look in the back with both brakes off to verify that the brake lights were on also. To be safe, I put it in first gear so I could catch the bus once I had checked.
You have a very dry sense of humor (I hope) LOL
Will :)
Start with the bulbs.
Rick
If you have double contact bulbs sometimes they can get crossed up in the sockets when the bulb tangs get pushed in, then they cause all kinds of weird things.
Well, this turned out to be a twofer. The parking brake light switch failed and had a substantial air leak. The service brakes have their own switch and that one is working fine. What itramounts to is that the parking brake light switch is normally closed, so since that is the switch that failed, I must have been driving with the brake lights on all the time.
I got a brake light switch from Napa that, although different looking, I thought would work. Anyway, that one turns out to be normally open (as the service brake light switch is) so it will not do. Tomorrow I hope they can get me the right one. If anyone knows the part number for that, it may help. Thanks
Hey Lin, hope that resolves it. You're right about it being normally closed, it takes air pressure to turn the lights off. The NAPA guy was able to cross reference the number on the side of mine to come up with one that worked, but I'm not sure if your MC-5 would have the same pipe fitting sizes even if the pressure specs are the same. Good luck with that, Will
You buy those by the number of lights used for the stop lights Bendix 274746-SL4 for 4 lights and 2 wire terminals
good luck
My brake lights have just one bulb each. Would you count the telltale to make it a total of three lights? I assume that a switch rated for 4 bulbs will handle a lower number too.
Lin,the SL-4 works on a 2 light system the SL-2 won't last on a 4 light system the guy sold you a low air pressure warning unit they look the same fwiw
Maybe Clifford, I think the low pressure switch had a 1/8 npt. He said this one is for the service brake, therefore normally open. The number you gave is a great help. It seems that they have modified the part and number to come up with this:
http://www.anythingtruck.com/product/060-274746N.html (http://www.anythingtruck.com/product/060-274746N.html)
Hopefully Napa can get one quickly.
If all it does is turn the brake lights on when parked why not eliminate it? (I don't don't like having brake light on just because it's parked and running)
A pipe plug should do the trick.
;D BK ;D
Quote from: B_K on January 07, 2014, 11:25:36 AM
If all it does is turn the brake lights on when parked why not eliminate it? (I don't don't like having brake light on just because it's parked and running)
A pipe plug should do the trick.
;D BK ;D
And a short jumper wire to close the circuit. (Sounds like something I would do) LOL
Will :)
Bk-I thought of that but somehow always think that if God created the 5a like that, He must have had a reason. Actually it is worse than the brake lights being on while the bus is parked and idling. They are on whenever the master switch is on.
Plugging it though, may be the thing to do and see whether it makes any difference to me. I assume it would put less wear on the stop light relay for one thing.
PP- You would not want the jumper wire since that would leave the brake lights on all the time. It is a normally closed switch.
I contacted Bendix to verify that the above number would work. It turns out that that one is also normally open so would not be good. They gave me a number (276185N) that is normally closed up to 12 psi. I checked online and it looks just like the one I removed.
Replacing parts with this old machine rarely turns out to be without including a few bumps.
You can use the normally open switch by just a relocation of the switch fwiw
Plugged it so the bus will be drivable but then found the switch on Ebay for $20. including shipping. I could not resist and bought it. If it only kept the brake lights on when the parking brake was engaged, I think I would just leave it plugged and forget it, but I like having the telltale, so I guess I will install the switch.
Quote from: Lin on January 07, 2014, 01:47:22 PM
PP- You would not want the jumper wire since that would leave the brake lights on all the time. It is a normally closed switch.
So much for my attempt at dry humor. :'(
PP- sorry for my density on that one.
Just passing this on in case anyone runs into the same problem, the Bendix part# 276185N is the right one. It is just like the one that failed.
I was unable to decide to stick with the 1/4" plug to bypass the system as BK had suggested or go back to God's original design of the sacred 5a. Choosing between BK and God is a rather tough decision. So I decided to go with a compromise. Since the valve is really just below the floor under the dash, I installed a toggle there so that the system can be used or bypassed at will. If you think that this was a silly waste of a couple of feet of wire, I am not prepared to argue with you. The real upside to this though is that I now have another toggle switch to be proud of. Isn't that what it's really all about anyway?
We can all be proud of another toggle switch as long as you have a tell tale to go with it. Otherwise, a switch is just a switch.
Check the floor mat if you have one.If the mat gets under the back of the brake pedal on my Previe ,it will hold it open enough to keep the brake lights on.Don,t know why these things are so sensitive but they are!!