Master Cyl. needs !

[butchpilot170]

Hi ! Anybody know what the size of the set screw ( that locks the top from unscrewing )near the top of the master cyl. is ? Could I just use a very small machine screw instead ? the ButchPilot !

[Bruce Fenstermacher]

Do not assume everyone has the same master cylinders as you do as there are several models. You could use find a machine screw that fits, then take it to ACE hardware and buy the correct size set screw.

[n2582d]

Bruce is right. The master cylinders shown in the 170A IPC don't even show a set screw. The master cylinders shown in the 170B and early 172 IPCs indicate that set screw to be an AN 565D6-3. The current equivalent in the Aircraft Spruce catalog is AN565DC6H3 or MS51021-22 which is a 6-32 thread 3/16" length set screw. I bet you could stick your magnet down in the bilge goop below your master cylinders and pull up five FAA-approved set screws.

[N2625U]

I bet you could stick your magnet down in the bilge goop below your master cylinders and pull up five FAA-approved set screws.

Or 6 screws, 8 washers, 2 sockets, 1 phillips screwdriver, a pulley and a 3/8 wrench like when I cleaned out the bilge in my 172 right after I bought it. I wonder what surprises people have found when they cleaned out the bilge.

[butchpilot170]

Thx ! I took your advise to try and retrieve things. I used a 54 volt electro magnetizer with booster to make sure I removed all metal things from master cyl. housing . Pulled out a whole exhaust system into cabin by completely removing all seats . Something didn't seem right so I opened oil access door , looked in ,and found out I had removed my own exhaust system somehow !. Looking for new ones since I mangled mine in the process !!!

[n2582d]

But did you find the missing set screw?

[cessna170bdriver]

To clean the “bilge” properly, you start by removing the firewall...

37DA12F5-8601-4975-90DC-5E603868429D.jpeg

[butchpilot170]

Nope, still searching !