mackmodelb Posted August 4, 2006 Share Posted August 4, 2006 I recently changed my rear quick release valve on my B-61. It does not seem to release quickly. The only way I can get it to release somewhat quickly is to crack open the supply line. Is it possible that the new valve is bad or is there some adjustment on them. I only have the original service manifolds on the rear and the front brakes were removed. Any suggestions would be appreciated. Thanks. Quote Link to comment https://www.bigmacktrucks.com/topic/1388-quick-release-valve-problems/ Share on other sites More sharing options...
fullfuel01 Posted August 4, 2006 Share Posted August 4, 2006 there is not only that valve that exhaust your system. it exhaust from the foot valve too, and don't know on Bmodel but on R model there is also one right behind the cab... Quote Link to comment https://www.bigmacktrucks.com/topic/1388-quick-release-valve-problems/#findComment-6932 Share on other sites More sharing options...
HK Trucking Posted August 4, 2006 Share Posted August 4, 2006 I recently changed my rear quick release valve on my B-61. It does not seem to release quickly. The only way I can get it to release somewhat quickly is to crack open the supply line. Is it possible that the new valve is bad or is there some adjustment on them. I only have the original service manifolds on the rear and the front brakes were removed. Any suggestions would be appreciated. Thanks.There may not be a problem with the QR valve.The problem may be "upstream", with the treadle valve (foot brake valve)It may not be releasing the pressure in the line leading to the QR valve, therefore the brakes don't release.By cracking open the line you are "manually" letting the pressure out, and then the brakes release.Be sure there isn't any binding in the brake pedal anchor pin, preventing it from returning to the released position after stepping on it. I have seen instances where a stone or other object would get jammed under the"heel" of the brake pedal & prevent complete release.Pull up the rubber boot around the plunger under the brake pedal & lubricate the plunger,making sure the plunger isn't jamming in the treadle mount.After a brake application, try to pull up on the pedal & see if it releases then.Disconnect the service brake line (the one coming from the pedal) from the QR valve & plug it off, then apply the foot brake,& release the foot brake. Now take the plug out of the air line. If there's still pressure in there, then the treadle valve is not releasing.If that's the case, time for a new treadle valve. 1 Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/1388-quick-release-valve-problems/#findComment-6937 Share on other sites More sharing options...
theakerstwo Posted August 4, 2006 Share Posted August 4, 2006 There may not be a problem with the QR valve.The problem may be "upstream", with the treadle valve (foot brake valve)It may not be releasing the pressure in the line leading to the QR valve, therefore the brakes don't release.By cracking open the line you are "manually" letting the pressure out, and then the brakes release.Be sure there isn't any binding in the brake pedal anchor pin, preventing it from returning to the released position after stepping on it. I have seen instances where a stone or other object would get jammed under the"heel" of the brake pedal & prevent complete release.Pull up the rubber boot around the plunger under the brake pedal & lubricate the plunger,making sure the plunger isn't jamming in the treadle mount.After a brake application, try to pull up on the pedal & see if it releases then.Disconnect the service brake line (the one coming from the pedal) from the QR valve & plug it off, then apply the foot brake,& release the foot brake. Now take the plug out of the air line. If there's still pressure in there, then the treadle valve is not releasing.If that's the case, time for a new treadle valve.you are right .Glenn Akers Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/1388-quick-release-valve-problems/#findComment-6938 Share on other sites More sharing options...
Satish reddy Posted May 29, 2019 Share Posted May 29, 2019 Qr value is lekaging while holding the wall with hand to stop air brake is applying what is the problem Quote Link to comment https://www.bigmacktrucks.com/topic/1388-quick-release-valve-problems/#findComment-423873 Share on other sites More sharing options...
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