International 1992 Brake Press Light?

[ihowell2077]

Hello everyone! This is my first time on the Skoolie Forums and my first school bus conversion project!

I ended up getting very lucky through craigslist and got a good deal on a 1992 international that was fleet maintained until just recently. I purchased the bus off a retired bus driver and you could absolutely tell that this bus was her pride and joy. I took the bus home and everything was great.

The next day when I started it up the brake press light came on and a buzzer went off. I did a little research on the forums and lots of people mentioned that it could be something involving the power steering fluid. A friend and I popped the hood, but neither of us could locate the power steering fluid reservoir. The brakes work just fine, and I really don't think there is a problem.

Before I drove the bus home the other day the lady I bought it from pulled a fuse for the overhead flashers. I guess it's a felony to have them on. Does anyone else think this could just be an electrical problem? Any sage advice to go about fixing this?

Thanks everyone!

 

[JakeC-SKO]

Does the buzzer stay on, or does it go off after a little bit? What engine do you have? I have a 1991 International with a DT466 and the reservoir is in the front on the driver side, BUT it has NOTHING to do with the brake pressure. Like, absolutely nothing, lol...

 

[ihowell2077]

Not sure what sort of engine I have....I can check once I'm home.

The buzzer does stay on. It comes on right after I disengage the E-Brake when I start the bus. There have been a few people on here who have mentioned that the two are somehow related. That doesn't make much sense to me, but it wouldn't hurt to check.

 

[bansil]

you didn't open any of the doors and maybe not latch them did you? or left them locked?
Some buses have very wired "safety wiring"

 

[ihowell2077]

@ jake c: I've heard a few people talk about the brake press light somehow being bundled in with the power steering system. Not really sure how that would work, but it probably wouldn't hurt to check. The buzzer does stay on while I am driving.

@Bansil: I'm pretty sure all of the doors are completely shut. I could try and check again.

 

[Redbear]

If you have air brakes, there will be a buzzer that warns you not to drive until both air tanks have enough pressure to work the service brakes. The parking/emergency brakes, or "spring brakes," work on the absence of the air that holds back the engagement springs while moving. Air brakes also do not have brake fluid nor brake fluid reservoirs, so you would not be able to find one.**

If you have power-assisted hydraulic brakes, then there should be a buzzer that warns you if you lack engine vacuum to operate the power assist. Heavy vehicles with hydraulic brakes should have an electric vacuum pump to assist the engine, because the engine vacuum drops to zero or nearly so when your pedal is to the metal.

In either case, if you run the engine a bit and the buzzer stops and the light goes out, and does not come back on as soon as you step on the pedal, you are probably ok.

If you have air brakes, you must have two air pressure gauges, or one dual-needle gauge. You should read up on pre-trip tests for your air brake system. If you have hydraulic brakes, you may instead have a vacuum gauge on the panel in addition to the light and buzzer.

** Some posters here at skoolie.net have referenced "the dreaded Lucas-Girling air-over-hydraulic brake" system. I am not familiar with that hybrid, so if that is what you have, you are on your own . . .

 

[Crazy]

Welcome to the forum. I think it's what redbear wrote, air pressure building up. But seriously, if you are going to ask anything about mechanicals, you need to give more information about the bus. Otherwise everyone is just guessing as to what the problem might be. If you do have air brakes, you need/must learn how they work. Completely different from a car.

 

[ihowell2077]

Ok everyone. Thanks for all of the advice.

After a bit of tinkering I came to the realization that as I shut down the bus I need to first turn off the electrical system before shutting down the engine. This seems to do the trick. I thought I had a serious electrical problem. The brake lights would stay on after the bus was shut off, the Brake press light would randomly turn on and the buzzer on the back door would go off after the bus was shut off. By simply correcting the process of start up and shut down all of the problems went away!

Thanks!

 

[alpharv]

I have a 1998 int. with the dt530 and when i turn on the truck some times the brake peddle light and buzzer will not turn off. I push on the brake peddle and the booster does make a noise showing that the booster is working. some times it takes 4 times of turning the truck off and on before the buzzer goes off. HELP

 

[Brad_SwiftFur]

I have a 1998 int. with the dt530 and when i turn on the truck some times the brake peddle light and buzzer will not turn off. I push on the brake peddle and the booster does make a noise showing that the booster is working. some times it takes 4 times of turning the truck off and on before the buzzer goes off. HELP

You don't say if you have hydraulic or air brakes, but since you mention a booster I'm assuming hydraulic brakes. The warning light and buzzer basically says it senses low hydraulic pressure, normal when the engine is off. When the engine is running, the pump (not the booster) should provide hydraulic pressure to assist the brakes. The booster does this with the engine off. I'd check (1) hydraulic fluid level. Yes, sometimes it really is that simple. (2) hydraulic pressure sensor (3) hydraulic pump and system. I'm guessing it either "thinks" the pressure is low, or the pressure really *is* low.


If it has air brakes, the warnings will likely be low air pressure. Idle engine and let air pressure build up and it should turn off around 60 PSI.

 

[alpharv]

Brad where would i find the hydraulic pressure sensor? I do have a split brake system. one side of the system is the normal brake fluid side and the other side is running off the power steering all my fluids are full. Today i disconnected the relay that is screwed to the side of the brake fluid tank bracket and then reconnected the relay and the truck started and no light or buzzer after start up. i will try to start the truck tomorrow to see if the buzzer stays on and if so i will do the relay again. maybe that is my problem. but still would like to check sensor thanks

 

[Brad_SwiftFur]

Brad where would i find the hydraulic pressure sensor? I do have a split brake system. one side of the system is the normal brake fluid side and the other side is running off the power steering all my fluids are full. Today i disconnected the relay that is screwed to the side of the brake fluid tank bracket and then reconnected the relay and the truck started and no light or buzzer after start up. i will try to start the truck tomorrow to see if the buzzer stays on and if so i will do the relay again. maybe that is my problem. but still would like to check sensor thanks

I haven't worked on a hydraulic system like this and don't have easy access to one to look at. Can someone else offer more insight than I can?