What is happening when i crank up and build air pressure up when it cold out side there is all this air hissing in the dash under the parking brake application knobs and usally after the truck warms up it stops after applying and releasing a few times but only in the winter time and doesnt do it again while the truck is warm only after its been sitting in freezing conditions !
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Parking brake knobs
- Thread starter chucky
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The seals in the control valve assembly have failed. This is the one you need:
Mine did the same thing after years in the desert. I recall taking it apart and not really being able to fix it - don't recall off the top of my head why but I think it was due to the seals not being generic o-rings and the condition of the plastic knobs was also pretty terrible from the sun so I just changed the whole unit. I got one a year ago off ebay for $75 shipped so you might do some additional digging. I bought a Bendix replacement from NAPA but wasn't quite the same and didn't have threaded bosses for mounting so I went looking for the original Haldex part.
Mine did the same thing after years in the desert. I recall taking it apart and not really being able to fix it - don't recall off the top of my head why but I think it was due to the seals not being generic o-rings and the condition of the plastic knobs was also pretty terrible from the sun so I just changed the whole unit. I got one a year ago off ebay for $75 shipped so you might do some additional digging. I bought a Bendix replacement from NAPA but wasn't quite the same and didn't have threaded bosses for mounting so I went looking for the original Haldex part.
coachgeo
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catch 22..... that one is harder to install on A0 trucks...but less costly I think. You have to cut a opening in the A0 plate. Least I dont recall anyone who has removed the knobs and somehow inserted it in the OEM holes. That one you linked is standard at some point on A1's. On A0 it is a tight space thing compounded by stiff hoses that makes it a bit of a PITA . Can one even get the individual valves anymore though?
I dont think (lol) i need to replace them im thinking maybe ice is getting in the valve because as soon as things heat up like the air from the compressor and it warms up it works fine ! I thought maybe someone from the cold country in here has had this happen to their truck???
coachgeo
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well..... in cold things contract.... and if rubber bits and parts making up the valve etc. are already old, stiff and partially contracted (but still in the envelop to not leak in warm weather); then swap to cold weather causing them to contract more..... you get leaks. Whey they warm up and expand some.. leak stops... aka.... this could explain your issue as well maybe?? ... hence back to they may need replacing...... though imho... maybe some air compressor lube run thru it for a while to rejuvenate the rubber might help and this might buy you some time before replacement? some airline antifreeze might be good too.
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If there's ice in it you desperately need to service your air drier.......
But really coachgeo has the right answer - rubber shrinks in the cold.
The whole assembly is not that expensive - replace it and move on. If it's a PITA to get it out on the A0 trucks then this is an opportunity for an upgrade and to modify for easier future service.
But really coachgeo has the right answer - rubber shrinks in the cold.
The whole assembly is not that expensive - replace it and move on. If it's a PITA to get it out on the A0 trucks then this is an opportunity for an upgrade and to modify for easier future service.
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Side note - this just means you need AC on your A0 truck and then the brake valve will fit the new AC center console correctly. Problem solved via application of wallet.
Third From Texas
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Try a mist of WD40, etc.
My truck had that issue and I ordered replacement valves. Then I saw a video where someone suggest getting a little lube down that long hard shaft. What do ya know? It worked and hasn't hissed at me in years.
;p
My truck had that issue and I ordered replacement valves. Then I saw a video where someone suggest getting a little lube down that long hard shaft. What do ya know? It worked and hasn't hissed at me in years.
;p
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Tried that before I left Texas with my truck. Worked for a short time and started leaking again. But my truck went to Kuwait and then lived in El-Paso the rest of it's life after so mine was wrecked with fine dust. The seals were garbage and weren't coming back for me.
See now thats tha kinda shat im talking about !!! Easy fixs some time back i watched someone on youtube fight replacing a set of valves and got lines put back on backwards so was really hoping to NOT do that !!!! Just hit the EASY button !
Yea my drier seems to be doing good /compressor/ not putting any oil in the lines (knock on wood ) nothing in air tanks when i bleed them
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The drier needs to be serviced annually, or more frequently in wet climates. Mine was never serviced since 2008 when the truck was built and it destroyed my compressor on the 2700 mile drive home (truck had 2750 miles when I left TX, about 5400 when I got back to OR). I had no signs of anything in my tanks and never did - no water or oil. The backpressure from the saturated drier caused the compressor to overheat and the reed valves failed and parts of them went into the cylinder and punched a hole in a piston. When I say destroyed I mean DESTROYED. And it's not a cheap fix. I had to source a core compressor because mine was not rebuildable, and besides the cost to buy/ship the core I had it rebuilt also and then still had to service the drier, etc. I do all my own labor and did the R&R on the compressor myself - I could have done the rebuild but the cost to have it done by Brake Systems Inc amounted to what I charge for a couple hours of my own labor so I just let them do it since they are local to me and sourced the core to be rebuilt from one of their used parts suppliers in TX. Have not had any issues since and still have zero water or oil evident in my tanks when I drain them. That little incident almost kept me from getting home, put my truck down for about 5 weeks, and cost close to $1k.
Service your drier.
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Service your dryer. Less than 1 year on this cartridge:
So today i used some cable lube and sprayed the brake vales on the dash to wet the orings and SHAZAAAM it worked and it was the trailer valve causing the problem but lubbed both for good measure ! Good call PLAYER !!!!
Third From Texas
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Lil' lube on the shaft works wonders !
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The seals I encountered were not "o-rings" (quad-rings? I don't remember but if it was a simple o-ring I would have rebuilt it right there and not ordered a new one.... and yeah I should have a quad ring assortment but I digress.....) thus why I did not replace them. I did lube them with Dow Corning 111 and they worked till I replaced it but it was not a permanent fix for me. Rubber doesn't come back from being dry, shrunken, and worn away. IMO that's a temporary fix and when it fails again will it be as simple as ordering a new one or will we be scavenging the carcass of a dying society? I'm getting the new part while I can......