BELT TENSIONER

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I’ve discovered a significant leak coming from the valve lever—it leaks when on but not when off.

My manuals don’t provide information on this assembly. How do I go about re-gasketing it?

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Can’t tell much from the pic but I’ll bet it’s in the “toss it and buy a new one” category.

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Ditto that. Some things aren’t worth repairing. Especially when a $5 ball valve from Lowe’s might work just as well.

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Mine also has a check valve that maintains belt tension if the auxiliary pressure drops when the engine is off. Since my check valve was inoperative, I replaced it along with the regulator.

 

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Tad, I encountered a similar issue with my ’85 8V92 and found that the cylinders responsible for belt tension needed to be rebuilt. One or both of them were likely leaking air, allowing it to escape back to the atmosphere. You can get a rebuild kit for them, though Prevost mentioned they might not last long after a rebuild. I rebuilt both of mine, and they are still functioning on that coach. During the rebuild, I rotated the brass canister 180 degrees and cleaned the inside with crocus cloth before reassembling with new O-rings.

 

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I agree with Pete.

This is a three-way valve. In one position, it loads the belt tensioners, and in the other, it unloads them. If the cylinders are leaking internally, the leaking air returns to the valve and escapes out the exhaust side. I rebuilt both of my cylinders with kits from Prevost. The kits include high elastomer O-rings and retaining clips. I also disassembled the valve, cleaned it, and replaced the O-rings. The rebuilding process is straightforward; if you need assistance, feel free to contact me.

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