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Autor | Thema: NEUE Dichtung Bremstrommel - New Brake Drum Seal ref 1562892 (Gelesen 8255 mal) | |||
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Rubber extruded bullets would not work as intended. It requires lead shot-the same as what is in shotgun shells-Maybe even the correct size i.e No 4 duckshot.
"This could be due to environmental laws forcing lead to be banned from use (like asbestos in brakes)." I doubt it----- lead shot would be banned in Europe other wise no bullets or shotgun shells would allow hunters to poision themselves from lead shot contaminated wildgame As mentioned by other members it is important for weight of lead using centrifulgal force to lift the seal lip (Skirt) at speed. The lead is also lubricating that is why steel balls are not used. Also there is a pressurised line to pump compressed air into each drum when truck was pushed through muddy water. Check for small rubber line to each brake backplate. If you drown wheels the system should work if the seals have not lost their integrity/split or lost lead balls. The other option is to remove the seals altogether and clean each drum out after every muddy crossing. Stuff that for a joke If you go the expensive disc brake option you still have exessive disc wear from muddy environment. Have you ever seen how much shit is backed up on the calipers after each muddy crossing? I have read that disc brakes are not more efficient than drum brakes if well designed-Just cheaper to make and less parts. | ||||
johnny
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Hi johnnyk.
As said, I am still learning every day. I noted the air vent piping, originally assuming (without further consideration) that it was an air vent, not an air pressure line. Clever idea again. All of my 4 brakes do not show dirt inside, even with old cracked rubber bullets seals. Of course I don't know the history of the vehicle, and its off road usage (or not). I would know the reason of the rubber bullets seal version … I guess only Volvo, or well-documented people, could give an answer. So, here is a poll to this forum members : would you tell us if your brake drum seals are lead balls type, or rubber bullets type ? | ||||
C303 and Mercedes 280GE
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Mine are leadballs. She likes big Balls
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johnny
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OK …
I have to apologize again … After deep cleaning, I realized that … my old seal has lead balls, too. Shame on me … I also got the new seal for a few days (thanks, buddy !!), and it has lead balls too. Only one type of seal, then. Hopefully, finally. The bad news : I am afraid that the price of the mold will go up a lot, due to additional complexity for lead ball cavity. More info in the next weeks. The good news : It is easy to remove the lead balls from the old seal and place them back. So there is no need of buying balls separately. I still have an opportunity to make it a lot easier, but it depends on other people's good will, and it's totally out of my control. The go-no go decision can only be taken after clarifying this opportunity. Thanks for all informations shared here !!! | ||||
C303 and Mercedes 280GE
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Macfun, check the Lead ball size against shotgun cartridge lead balls. If I am not wrong there is a size that would be very close to what Volvo originally used. The older balls in the seal would have wear on contact of the metal seal ring so it would be easier to replace with new lead shot from a unfired shotgun shell. You have to be carfull removing balls from unfired shell.
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johnny
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Lead ball is 4 mm diameter.
124 balls per seal. | ||||
C303 and Mercedes 280GE
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if you´re afraid of opening shotgun cartridges, try some fishinggear... the weights may not blast straight in your face, but be aware of sharp hooks
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Any progress on the project? Would love to help out when and where possible.
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I was wrong fellow members-- the line that goes to back of drum is not pressurised to keep positive pressure in each brake drum cavity. It is part of elaborate air breathing venting system that connects to gearbox VTG and bell housing. Would have been more usefull if it was presurrised. I think the Unimog has this pressure system can someone tell me please | ||||
johnny
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Nah it not dangerous to remove lead balls from shot gun cartridge shell just don't strike the centre rear primer. Easy to unfold the skirt at front. The lead spheres are accurate compared to fishing lead sinker because they are made from sifted grid on top of a tower and cool as they are dropped into water. Take care Johnny | ||||
johnny
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Unimog even including headlights....:)) (similar are only aftermarket lights with goretex membrane; externalizing that same opening would do the same of course) That said: if you push enough volume/minute into a drum, at some point it would win from any pressure of water/mud, even with large gaps. (pressure increases by 1 bar for every 10m of depth, so technically it would be 0.1 bar at most, at 1m depth (static, not dynamic)) Btw, in that same context most interesting would be the scenario of water with soap. Willem (BubbleFest) Jan | ||||
*Verkaufe Battery-Equalizer/Charge-Balancer/Wandler 24->12v/100A* Those who wander are not necessarily lost J.R.R. Tolkien ...and not all who launder are washed/WJ....;)) <w.j.markerink@A1.NL>
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Willem (BubbleFest) Jan
I think you are dreaming of Spabath with the bubbles. That what I like about the Unimog-the designers thought about the design and tested the function before putting into production | ||||
johnny
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The drum brakes are vented for the same reason the axles are vented. When something is sealed and warm (due to friction) and then pushed under water, the trapped air will cool and contract, creating an underpressure inside your drum/axle. You then have the risk of water being pulled into said drum. Venting your drum or axle prevents this.
If your drum/axle is very deep in the water (0,5 to 1 m) the water pressure can be become very high. At which point you seals will likely fail. Pressuring said drum/axle counteracts the water pressure and keeps everything dry (in theory and if your seals are in mint condition) Greets, Thierry | ||||
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Has anyone made a succesful reproduction of the brake drum seals? All of mine has cracked and needs replacing.
Regards Anders | ||||
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Tatanka 128€ unbelivable | ||||
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Yes, I believe that reproduction could end up being cheaper
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Well ... For the story ... We were close to get an agreement to use the original mold at a belgian rubber injection company. A price estimation was made for a production of 1000 to 2000 seals. A visit of Tatanka was almost planned. But for unclear reason(s), Tatanka cancelled the visit. It might be due to lead balls availability and installation work ... I don't know ... Finally Tatanka decided to make injection in another country, where the seal AND the balls were probably assembled ... maybe ... I understand that for private use, it is not important if you have to spend one evening removing the lead balls from the old seal, and insert them in the new seal. But for hundreds of seals, it becomes quite boring (not counting that lead is not environment-friendly anymore). That was my original plan if I decided to make seals on my side (by 200 units) : to sell seals without balls, at a fair price. But mold building costs was huge (even if I got the original drawings for the seal). And I didn't want to pay thousands of euros plus another thousands of euros for first seals without knowing the return on investment. A lot of axles are now used for heavy offload races using brake discs. I even saw a east european company machining axle hubs holders and other parts out of aluminium block with CNC machines !!! So now I'm also switching (very slowly) to brake discs ... | ||||
C303 and Mercedes 280GE
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Thank you for your answer. Seems that I have to save up for Tatankas brake drum seals.
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Any word on Aftermarket Brake drum seals?
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johnny
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Well, rebuild project is on standby now ...
I found approaching V-shaped seals at Eriks webshop, but of course without lead balls possibilities. Volvo portals are common in asian countries for extreme offroad races, but never using original drums. Maybe they kept original drums and seals somewhere, but I believe seals lips are cracked, too ... | ||||
C303 and Mercedes 280GE
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