Newb- Question on Vacuum and Leaky Brakes

[Joseph Munoz]

So since im new to the Comanche world, I have a bunch of questions. I noticed low vacuum pressure in the plane. During the run up it is 4.5 and during flight at 4. Obviously below the limits of 4.8 to 5.1 After looking at the maintenance manual its either the vacuum regulator needs to be adjusted or replaced, or the vacuum pump could be going bad. Anyone have experience in this area what it most likely is? If i do neeed a new regulator or pump where are you guys going for parts? Does piper even carry anything anymore or is Webco the main supplier for most everything? Also the brakes are leaking a small amount on both calipers. Was there only one type of brake on the 1959 Comanche 250? Is it just one o ring or seal? If i am going to have a mechanic fix this is it worth it to do the pads at the same time since everything will be apart. Thanks for any info you all can give me since im a Commercial Helicopter by trade and a newb to the fixed wing world. I am loving the power of the comanche so far though.

[Kristin Winter]

IMX, if it was the pump, you would have higher suction in cruise than on the ground. I would look for leaks.

As for the brakes, there are two pistons in each caliper and each piston has an o-ring. They are not difficult to replace.

[SPNA]

Could be the vacuum gauge. I had one that was low just like you describe. After adjusting the regulator which didn't fix the low pressure, changing wet pumps, and checking for leaks I finally put a new gauge in and during the run up, the needle broke cause it was so high. Running with high pressure is just as bad as low pressure cause it can cause the gyro to fail early.