I blew a brake line in a dump truck once fully loaded coming up on a red light down hill with 20.36 tons of GAB! There was one car at the light coming to a stop and all the sudden POW! The low air horn sounded close behind, Primary air went rapidly to zero! I checked the turn lane in my mirror and took it to avoid hitting the car in front of me. I got it stopped but not like normal. The secondary tank did come through for me though, I had just enough to get stopped. The 07 KW T800 dump truck I'm in now will drain all tanks from any single tank being drained. Do you suppose its the double check valve causing it? I have a brand new Bendix AD-IS 801266 dryer installed but still have this issue. Although it did fix the pop off blowing issue!
@evildrmainstream...67675 жыл бұрын
Very helpful
@RipRoaringGarage3 жыл бұрын
Can anyone tell me how a "double check valve" with only TWO fittings works? Im translating this for my bus (its a classic and very foreign), and the diagram nor the cross section make any sense to me. It has a diaphragm check valve (lets say left to right), and is obvious. But then they say, that it allows air to flow from right to left through a small pin check valve (Im assuming, since its poorly drawn). What is the point of this since to me, it looks like air can flow in either direction with minimal resistance. I would curse out the Romanians for this (and they deserve it as the manual is very...VERY poorly written), but this is a license Knorr-Bremse design. I wish I had to part number and find out what this is. On the main diagrams, it seemed like just a regular ole check valve, but this second built in valve in the other direction really has me banging my head.
@learndiesel528
3 жыл бұрын
Ok it so I am assuming you mean it has only a inlet and outlet side so only 2 orifice. So I would guess that its actually the same as this valve except they are just using a different point of reference to explain the operation. Where as this valve is a one way check valve because it will only allow air to pass one way depending on pressure. They may be calling that a double check valve because the check ball can seal both orifices. Again this is my best guess. I would like to see the valve as well seems interesting.
@RipRoaringGarage
3 жыл бұрын
@@learndiesel528 Thanks for the reply. Took me a while, but I think I figured it out. So, the function of the valve was not what I assumed. It does prevent air from leaking out to a secondary circuit, but rather to use that circuit as a giant reserve tank. So, air will only enter the secondary circuit above a certain pressure under normal operation. So, the brakes will fill first, tehn suspension, doors, etc. If theres a leak in the main circuits, or the brakes, then theres an internal flapper that will let air go from the secondary circuit into the main leaking circuit for an extra boost of air. At least, thats what I could figure. I may do a video on this...Its VERY old tech, nothing electronic, minimal electrical system and all that. The manual in Romanian (my bus is Romanian but with lots of US and German licensed parts) is the big stinker. Poorly written, and it drives me nuts. Sometimes I figure it out, sometimes I have to get somebody to explain it to me...and sometimes, like here, as I talk it out, I kind of figure it out. At least I think I get the purpose of the valve, as the priorities back then were different for air management.
Пікірлер: 5
I blew a brake line in a dump truck once fully loaded coming up on a red light down hill with 20.36 tons of GAB! There was one car at the light coming to a stop and all the sudden POW! The low air horn sounded close behind, Primary air went rapidly to zero! I checked the turn lane in my mirror and took it to avoid hitting the car in front of me. I got it stopped but not like normal. The secondary tank did come through for me though, I had just enough to get stopped. The 07 KW T800 dump truck I'm in now will drain all tanks from any single tank being drained. Do you suppose its the double check valve causing it? I have a brand new Bendix AD-IS 801266 dryer installed but still have this issue. Although it did fix the pop off blowing issue!
Very helpful
Can anyone tell me how a "double check valve" with only TWO fittings works? Im translating this for my bus (its a classic and very foreign), and the diagram nor the cross section make any sense to me. It has a diaphragm check valve (lets say left to right), and is obvious. But then they say, that it allows air to flow from right to left through a small pin check valve (Im assuming, since its poorly drawn). What is the point of this since to me, it looks like air can flow in either direction with minimal resistance. I would curse out the Romanians for this (and they deserve it as the manual is very...VERY poorly written), but this is a license Knorr-Bremse design. I wish I had to part number and find out what this is. On the main diagrams, it seemed like just a regular ole check valve, but this second built in valve in the other direction really has me banging my head.
@learndiesel528
3 жыл бұрын
Ok it so I am assuming you mean it has only a inlet and outlet side so only 2 orifice. So I would guess that its actually the same as this valve except they are just using a different point of reference to explain the operation. Where as this valve is a one way check valve because it will only allow air to pass one way depending on pressure. They may be calling that a double check valve because the check ball can seal both orifices. Again this is my best guess. I would like to see the valve as well seems interesting.
@RipRoaringGarage
3 жыл бұрын
@@learndiesel528 Thanks for the reply. Took me a while, but I think I figured it out. So, the function of the valve was not what I assumed. It does prevent air from leaking out to a secondary circuit, but rather to use that circuit as a giant reserve tank. So, air will only enter the secondary circuit above a certain pressure under normal operation. So, the brakes will fill first, tehn suspension, doors, etc. If theres a leak in the main circuits, or the brakes, then theres an internal flapper that will let air go from the secondary circuit into the main leaking circuit for an extra boost of air. At least, thats what I could figure. I may do a video on this...Its VERY old tech, nothing electronic, minimal electrical system and all that. The manual in Romanian (my bus is Romanian but with lots of US and German licensed parts) is the big stinker. Poorly written, and it drives me nuts. Sometimes I figure it out, sometimes I have to get somebody to explain it to me...and sometimes, like here, as I talk it out, I kind of figure it out. At least I think I get the purpose of the valve, as the priorities back then were different for air management.