Posted By: Anonymous
Solution of sticking DV26.. - 05/07/2006 12:35
guys,
i used to have the same problem of james with My DV26, it was sticking and it was doing the same strange noise.. However after I read james thread and I saw a lot have the same problem, and as, im working in a valve’s manufacture and i have good knowledge of valves i decided to fix this dam valve!!
So, i striped it and i saw many cheap parts, which I don’t like!! The O-ring is “X” type i.e. has two lips contact with the sealing area, the body & the sealing area are from aluminum and the piston is made of plastic!! IMO it is really a bad design.
The real resone of sticking & producing this sound is the O-Ring. It has bigger diameter than required, and once you apply boost pressure the O-ring it runs out from the groove and cause the piston to stick with the sealing area (the inner valve body). This will allow the valve to be opened all the time and release the pressure immediately, until the piston runs from the O-ring and come back to its place. This process is happening every time you increase a pressure and it will leave a big defect on the piston surface and the sealing area as well. Accordingly, you will hear a strange sound from the valve.
i made a complete study to make it work, so i did the following:
1. I have changed the O-ring to “O” type not “X” which has only one contact with the sealing area.
2. I polished the sealing are to make it smooth.
3. I polished the Piston Surface as well for better sealing
4. I greased the whole piston including the O-ring and sealing area.
5. I replaced the gasket with new one.
6. Done and ready for road check.
After a short trip, I found that it is running perfectly and the car was very happy with it.
I am using it for more than a week now, its working freely without any sticking and its producing a very lovely sound even better than before..
This solution will work fine but I recommend the following to be done:
1. It will be better to use Stainless Steel valve than aluminum.
2. The Piston has to be also SS not plastic as used.
3. The O-ring Groove has to be with radius not sharp as it can cut the O-ring itself.
Anyway, if anyone wants to repair it as well, just send it to me and I will do it for free for FCCUK members…..PM welcomed
Cheers
i used to have the same problem of james with My DV26, it was sticking and it was doing the same strange noise.. However after I read james thread and I saw a lot have the same problem, and as, im working in a valve’s manufacture and i have good knowledge of valves i decided to fix this dam valve!!
So, i striped it and i saw many cheap parts, which I don’t like!! The O-ring is “X” type i.e. has two lips contact with the sealing area, the body & the sealing area are from aluminum and the piston is made of plastic!! IMO it is really a bad design.
The real resone of sticking & producing this sound is the O-Ring. It has bigger diameter than required, and once you apply boost pressure the O-ring it runs out from the groove and cause the piston to stick with the sealing area (the inner valve body). This will allow the valve to be opened all the time and release the pressure immediately, until the piston runs from the O-ring and come back to its place. This process is happening every time you increase a pressure and it will leave a big defect on the piston surface and the sealing area as well. Accordingly, you will hear a strange sound from the valve.
i made a complete study to make it work, so i did the following:
1. I have changed the O-ring to “O” type not “X” which has only one contact with the sealing area.
2. I polished the sealing are to make it smooth.
3. I polished the Piston Surface as well for better sealing
4. I greased the whole piston including the O-ring and sealing area.
5. I replaced the gasket with new one.
6. Done and ready for road check.
After a short trip, I found that it is running perfectly and the car was very happy with it.
I am using it for more than a week now, its working freely without any sticking and its producing a very lovely sound even better than before..
This solution will work fine but I recommend the following to be done:
1. It will be better to use Stainless Steel valve than aluminum.
2. The Piston has to be also SS not plastic as used.
3. The O-ring Groove has to be with radius not sharp as it can cut the O-ring itself.
Anyway, if anyone wants to repair it as well, just send it to me and I will do it for free for FCCUK members…..PM welcomed
Cheers
