i am having problems intermitten with the brake pressure light and alarm going off but intermitten it will happen today on start up then cycle key and it will go away and wont do it for couple days then it will do it every other start up then be fine for couple days i been thru this before with this bus ievry time i go to check it its fine so i put a need flow switch in it and it was good for a month thought i had it but nottt this has the psi gas motor in it could it be a power steering pump issue but i never lose power steering but i am thinkin its gotta be a hydrolic issue any ideas
Many units are currently on recall for a defective pressure switch on the brake fluid circuit. You need to check if yours in affected. Feel free to post the last 8 of the VIN and I'll check for you.
Long story short, brake fluid leaks through the switch and into the wiring harness. Symptoms that led the the recall were trucks with alarms, hydroboost motors running, and in some situations there have been fires.
Not saying this is for sure your issue, but it's a possibility.
This was a pressure sensing switch that actually has brake fluid going to it, not the mechanical differential switch on the side of the master. You bus is not affected by that recall though.
exmod110 makes a good point about the diode and pins.
Note: your unit does have an outstanding recall for ECM calibration. This needs to be done for safety reasons as it can cause engine stalling.
You are also open for safety recall 23518 "Brake Pressure Switch on certain 2016 IC BusŪ CE school buses built on 06/04/2015 and certain 2018 through 2024 IC BusŪ CE school buses built 12/15/2016 through 05/18/2023 with feature code 04100 (Brake system, hydraulic)" It talks about fluid leaking past a diaphragm
we actually got the recall letters in the mail yesturday for all our gas buses with hydro brakes lol and apparently there is a recall on the roof hatches as well no letter for that but when called dealer we told them the hatches where leaking and he said o yeah there is a recall on them as well but when i got on roof now mind u we just got this bus in it has 1500 miles on it the roof hatch was soooo worped the packed in the kind of seal i mean there where gaps where it meets the roof no lie about 2 inches thick of some sort of glue it was unbelieveable i wish i could post pictures on here
Yeah I just saw the expanded recall for the brake pressure switches this morning. Not sure if it's the same issue as you are seeing with your hatches, but there was an issue with the machine that forms the roof bows that caused things to not seal up correctly. I had 2 buses affected by that one.
2020 ic hydro brakes
Posted - 07/20/2023 : 04:31:58 AM
