Hook n ladder 1 Posted October 17, 2010 Share Posted October 17, 2010 98 CH 613. Left side ABS valve ( inside framerail...a few airlines and an electrical connection )leaks at the diaphragm on the bottom. I replaced it once and its leaking again but not all the time. When it leaks down to about 80psi I get a "malfunction" light on the dash. Is the new valve bad or is it an ECM issue/ Quote Link to comment https://www.bigmacktrucks.com/topic/16173-losing-air-at-abs-valve/ Share on other sites More sharing options...
theakerstwo Posted October 17, 2010 Share Posted October 17, 2010 98 CH 613. Left side ABS valve ( inside framerail...a few airlines and an electrical connection )leaks at the diaphragm on the bottom. I replaced it once and its leaking again but not all the time. When it leaks down to about 80psi I get a "malfunction" light on the dash. Is the new valve bad or is it an ECM issue/I think you are talking about when you hold down the foot valve. Us play like that is what your saying and that it ius a wabco. The most problems i have seen with them leaking when air is applied is trash in the valve and holding the seat open. Some times it is rust from the brake chamber. If it is rust you some times can do a accuator test were it purges the valve and that is did under full foot valve pressure. This will clear the rust some times.If it does pull the chamber apart and take a look. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/16173-losing-air-at-abs-valve/#findComment-65496 Share on other sites More sharing options...
Hook n ladder 1 Posted October 19, 2010 Author Share Posted October 19, 2010 I didnt get a chance to finish my question...when the parking brake is released the abs valve leaks. This abs valve is before the brake chamber so I dont think its rust from the chamber. If i pull/push the parking brake knob a few times it eventually stops leaking. and once it stops i dont have any problems with it unless i set the brake again. Quote Link to comment https://www.bigmacktrucks.com/topic/16173-losing-air-at-abs-valve/#findComment-65543 Share on other sites More sharing options...
theakerstwo Posted October 19, 2010 Share Posted October 19, 2010 This is i guess a rear chamber with the parking brake on it. If so sounds to be leaking thru the spring chamber in to the service side. To check it is simple and you would with the parking brakes released disconect the service hose to the chamber and there should be no air coming from the service port of the chamber. If it is replace the chamber. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/16173-losing-air-at-abs-valve/#findComment-65544 Share on other sites More sharing options...
Hook n ladder 1 Posted October 19, 2010 Author Share Posted October 19, 2010 Its not a brake chamber. its an anti-lock brake valve with air lines and an electrical connector. Its mounted inside the frame rail. there's one on each side above the first drive axle. Quote Link to comment https://www.bigmacktrucks.com/topic/16173-losing-air-at-abs-valve/#findComment-65560 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.