Author |
Message |
Airless in Mississippi (68.243.168.226)
Rating: N/A Votes: 0 (Vote!) | Posted on Wednesday, September 15, 2004 - 8:36 pm: | |
I apparently am having a brake issue. If I take and disengage the emergency brake something does not totally disengage on the front calipers. The idiot light stays on. I can move the bus forward and while pressing gas step on brake peddle hard and disengage brake. This works until the next redlight and have to do the same thing without doing this the brake is engaged yet when I do hit it hard it does release. You guys are the brightest so I know someone has the answer since they dealt with it before. The threadle valve is leaking I noticed when I landed. ON a side Note I really got to get bus air or large enough invertor to run ac off of bus alternator. Man it was hot moving this big tent around |
R.J.Bob Evans (142.165.167.158)
Rating: N/A Votes: 0 (Vote!) | Posted on Thursday, September 16, 2004 - 12:10 am: | |
You don't seem to be getting any help so I will wade into this. But remember - this is free advice and may well be worth exactly what you paid for it. Your problem sounds to me like a QRV (Quick Release Valve). Newer air systems will have the QRV and a relay valve combined into one unit. Either way, the purpose of a QRV is to release the brakes when the pilot pressure from the treadle valve is released - that way all the air from the brake pots doesn't have to bleed all the way back to the foot treadle. It sounds like yours is sticking. IOW, you need to replace it - they aren't expensive but they can be a real PITA to get at. It will be a small (~6" diameter) flying saucer shaped object with a bunch of brake lines coming out of it located somewhere between the front wheels. |
Buswarrior (Buswarrior) (64.229.210.244)
Rating: N/A Votes: 0 (Vote!) | Posted on Friday, September 17, 2004 - 12:45 pm: | |
Hello Airless. What bus and vintage do you have? Which idiot light stays on? The emergency brake doesn't do anything with the front brakes, so I'm worried that we're not getting the whole picture. RJBE has a good suggestion to check the quick release valve at the front axle. You will find it smaller than RJBE describes, with three lines attached to it, equal distant from each wheel end, near the centre of the axle, attached to the chassis. (no relay valve at the front) happy coaching! buswarrior |
Airless in Mississippi (68.243.163.11)
Rating: N/A Votes: 0 (Vote!) | Posted on Friday, September 17, 2004 - 2:41 pm: | |
The bus is a 1987 Mci 9. The emergency brake light stays on. The brake treadle (the unit directly below the brake peddle) Is leaking air out of what appears to be a little diaphram at the bottom of the treadle. My air pressure is not building up on the coach as fast as it was. The bus still has the air starter but normally after 5 minutes the pressure had built up now might be 30-45 minutes. |
Marc Bourget (209.142.38.81)
Rating: N/A Votes: 0 (Vote!) | Posted on Friday, September 17, 2004 - 4:09 pm: | |
Airless, Did you adopt your "handle" before or after this apparent leak showed up? So much for an attempt at ironic humor, I'll come to find out you're a retired professional painter, or something. Hope the solution is easy. I'll be lurking since I, too, have a MCI-9, but no problems with the brakes, yet! Onward and Upward Marc Bourget |
Airless in Mississippi (68.243.232.97)
Rating: N/A Votes: 0 (Vote!) | Posted on Friday, September 17, 2004 - 5:21 pm: | |
Nahh this nick came from having the bus without a/c in Mississippi. 98 degrees with 100% humidity combined with a steel tent makes it really hard when married. I did however finally land two rooftop a/c but the bus air still no luck with. The problem with the brakes is the first I have had. I purchased the bus in Oct last year and driven it nearly 14k miles with no problems. Park for 3 months and this shows up. |
Buswarrior (Buswarrior) (64.229.211.4)
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, September 20, 2004 - 11:43 pm: | |
Hello Airless. You've got a problem in your DD3 parking brake circuit. One way it will manifest itself in leaks out through the treadle valve. My paper resources are not at hand. Someone else jump in here and tell him which diaphragm he needs to look for. happy coaching! buswarrior |