burgessbuilderMO13
Active Member
Recently I posted a query regarding loss of manifold pressure indication using a vans man press guage and install kit. It had worked well for years and over 500 hours.
It turned out to be a longitudinal crack in the small clear vinyl hose from the firewall fitting to the transmitter.
At a low value of vacuum (not much) it was fine, but when more vacuum was applied (example engine at idle) the weakened section of tube would open into itself causing a large leak.The indicator of this was a normal pressure on startup, soon followed by a return to 25" mp at idle. Some portions of the hose were like new, others had become quite stiff.
The moral of this story is to find some new tubing that fits and change it out before you have an issue.
An easy fix when in your home hangar.
Dale
It turned out to be a longitudinal crack in the small clear vinyl hose from the firewall fitting to the transmitter.
At a low value of vacuum (not much) it was fine, but when more vacuum was applied (example engine at idle) the weakened section of tube would open into itself causing a large leak.The indicator of this was a normal pressure on startup, soon followed by a return to 25" mp at idle. Some portions of the hose were like new, others had become quite stiff.
The moral of this story is to find some new tubing that fits and change it out before you have an issue.
An easy fix when in your home hangar.
Dale
