Marcel67 Posted January 15, 2014 Share Posted January 15, 2014 The valve on my brake pedal keeps getting stuck on my MH. Could this be fixed by simply lubricating or should I replace the brake pedal assembly complete. What would be the correct part nr. The valve dos not leaking air just get stuck and when tapped with hammer lightly it comes loose. Please advice. Quote Link to comment Share on other sites More sharing options...
thomastractorsvc Posted January 16, 2014 Share Posted January 16, 2014 you can take that button out and clean it and the inside where it rides put a little anti-seize should be good, usually corrosion since aluminum or dirt Quote Robert"I reject your reality and substitute my own." Link to comment Share on other sites More sharing options...
farmer52 Posted January 16, 2014 Share Posted January 16, 2014 air valve assembly is 20QE3245M Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment Share on other sites More sharing options...
Mack Doctor Jr. Posted January 16, 2014 Share Posted January 16, 2014 I got the same prob with mine. I can't get any of the bolts apart or even get the pin out at the bottom. I could surely get it out if I had more time. Quote Link to comment Share on other sites More sharing options...
BC Mack Posted January 16, 2014 Share Posted January 16, 2014 Marceldo you have to lean down and pull the pedal up? some air still showing on the application gauge?generally it is the cross pin seizing or the plunger sticking... pin is the most common and can be a pain to get out if the housing is corroded.pin kits have new bushings in nylonwe had that issue with our fleet so now it is a dismantle, inspect, clean and lubricate on the 72,000km PM...photo of an MH pedal partially stuck downBC Mack Quote Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted January 16, 2014 Share Posted January 16, 2014 you can take that button out and clean it and the inside where it rides put a little anti-seize should be good, usually corrosion since aluminum or dirtWhat he said on the plunger.P.B. Blaster on the pivot pin? (Keep it out of the plunger) Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
Marcel67 Posted January 16, 2014 Author Share Posted January 16, 2014 Would it be easier to replace valve with the plunger for a new one? Quote Link to comment Share on other sites More sharing options...
Marcel67 Posted January 16, 2014 Author Share Posted January 16, 2014 Marceldo you have to lean down and pull the pedal up? some air still showing on the application gauge?generally it is the cross pin seizing or the plunger sticking... pin is the most common and can be a pain to get out if the housing is corroded.pin kits have new bushings in nylonwe had that issue with our fleet so now it is a dismantle, inspect, clean and lubricate on the 72,000km PM...BC MackThe pedal moves but the brake stays locked. When I tap with hammer to the side of the base it comes up and the pedal works. Question is the plunger conected to the pedal?photo of an MH pedal partially stuck down 1 Quote Link to comment Share on other sites More sharing options...
BC Mack Posted January 16, 2014 Share Posted January 16, 2014 Marcel...to get just the plunger out you have to remove the pedal anyway... if the pin is seized to the pedal you've got to fix it or you will be back to square one... the pin really needs to be floating free and not sticking to the pedal or the housing.if you remove the valve from the bottom then, yes, the plunger will come with it... just seems to be the long way around.. and maybe more costly.on the back of the pedal is a roller, make sure it rolls.....with the valve removed there should be a rubber boot connected to the plunger which then fits on the lip on the top of the valve, that is what keeps the garbage out..lightly grease the plunger after a good clean or simply replace all the parts.. your callworth spending the time on to get right, downside of failure could be locked on brakes...BC Mack Quote Link to comment Share on other sites More sharing options...
Lmackattack Posted January 16, 2014 Share Posted January 16, 2014 We always sprayed them down with wd40 or PB....the water,dirt,salt,,, just makes them stick over time....try that first. May want to put some vice grips on the pin and see if you can brake it free....that can be a big part of the problem as well.... Quote Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted January 16, 2014 Share Posted January 16, 2014 The pivot pin on my R is frozen in the aluminum base, and pivots on the pedal...which is exactly backwards from the way it is supposed to be! But, it is quite free and causes no problem.I periodically spray it down with PB and tap on it, hoping it will free-up one day.At some point, I will need to replace the foot valve. Not being able to get the pin out makes it almost impossible to remove one of the retaininf nuts, which makes it pretty difficult to get the valve off the treadle plate.I really figure that I'll wind up having to replace the whole assembly since I can't get it apart the "right way". But, I'll continue the PB/tapping regimen until the last possible moment. That stuff will surprise you sometimes!By the way, the old manuals actually tell you to pull the rubber boot up and lube the plunger periodically. Normal maintenance. Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
Marcel67 Posted January 16, 2014 Author Share Posted January 16, 2014 We'll thanks for all the advice. Got it working again cleaned it up and put some grease or lubricated and it work like a new one again! 1 Quote Link to comment Share on other sites More sharing options...
doubleclutchinweasel Posted January 16, 2014 Share Posted January 16, 2014 We'll thanks for all the advice. Got it working again cleaned it up and put some grease or lubricated and it work like a new one again!Outstanding! Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment Share on other sites More sharing options...
farmer52 Posted January 16, 2014 Share Posted January 16, 2014 We'll thanks for all the advice. Got it working again cleaned it up and put some grease or lubricated and it work like a new one again!Who do we send the bill to? 1 Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment Share on other sites More sharing options...
Marcel67 Posted January 18, 2014 Author Share Posted January 18, 2014 Can I pay with food stamps! LOL Quote Link to comment Share on other sites More sharing options...
rickykarenpr Posted January 18, 2014 Share Posted January 18, 2014 change the air brake valve Quote Link to comment Share on other sites More sharing options...
gearhead204 Posted January 19, 2014 Share Posted January 19, 2014 some of the cross pins have a roll pin in them making it a real pain in the prostrate to get out you may have to wire brush the camel hump to find the roll pin and may have to drill it out. something about alum.steel salt and water. go figure! Quote Link to comment Share on other sites More sharing options...
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