Re: Remote Brake Fluid Reservoir

Posted by HH56 On 2021/9/20 14:09:47

That looks to be a very nice kit and a neat install. One question I have for remote fills on BTVs including Packards option was what provisions if any were made in the BTV to accommodate the relief port.

In one of the many threads on BTV failures it was found the relief port was blocked by a gasket on some and that a rebuilder had been filling the port with silicone on others. At the time this was speculated to be the primary cause of fluid getting into the vacuum section if one of the seals failed. On the hydraulic side seal, if that seal failed and the relief port was blocked fluid under pressure would be forced into the vacuum side. If the vacuum side seal failed with a blocked relief port, instead of being able to draw air into the canister it would not be as big an issue but any fluid that did leak via normal seepage (which Bendix said was designed into the system to keep the seal moist) would be drawn into the canister.

With an absolutely full reservoir on the BTV thanks to the remote fill container keeping it full, the relief port will be submerged in fluid. The hydraulic side leak would still be able to push leaking fluid out to the reservoir but it seems as if a vacuum side seal failure would lead to a large influx of fluid being drawn into the canister since the remote fill and gravity would be feeding it.

I guess a primary question would be exactly how important is the relief port and was the speculation wrong and was it discontinued on later versions. The repro cylinder casting for the BTV sold by a vendor for another mfg does not even have the passage drilled.