Lagging Manifold Pressure

[rstan]

[9089P]

[Zach Grant L1011jock]

[rstan]

[Zach Grant L1011jock]

[AlanBreen]

[Jay]

[Dale Vandever]

Hi Richard, you have been offered very good advice, that will probably reveal the culprit.

If all of that fails, remove the hose from the cylinder to the line that goes to the gauge. This is rubber and ls primarily there to absorb vibration. After operating in a very hot environment, while under a vacuum, the inner lining of the hose has been known to collapse the inside of the hose and restrict the maintenance of a constant pressure.

Remove the short hose and straighten it out so you can look through from end to end. If you can't see through the hose it needs to be replaced.

You will find the hose to have automotive SAE fittings, not aircraft. You can do the owner produced parts bit by taking it to a NAPA auto parts store. List the length, size, used in vacuum service etc. and give them the part They can duplicate the part for a very few dollars. Piper used SAE fittings in several locations This will enable you to maintain the type certificate prescribed fittings.

After this many years, you should probably replace it on condition.

Good luck,

Dale

[rstan]