Replacement for vacuum hoses

[CapPJ]

Over the past few months I noticed that my vacuum gauge slowly started indicating lower pressure readings both at idle and in flight. PSI had dropped below 4 while taxing and even in flight I was barely seeing 4.25PSI. When I told my AI during annual he said there was a kink in one of my hoses and he tried to relieve it. The low pressure is still indicated on the gauge but other than that no other symptoms. A couple days ago while trying to troubleshoot one of my post lights, I got into the inner side panel from the pilots side and thought to check the vacuum gauge connection. When I unscrewed the gauge and pulled it from the panel, I noticed the hose felt brittle and there was something inside (hose material debris?) There was also a crack, almost looked like a joint, where it was probably losing pressure. For sure I need to replace this hose, but I also want to replace the others since they also felt a little brittle and will most likely fail soon. I have a copy of the M20J parts manual but unfortunately I cannot make out the size of the hoses. This is figure 1 of 37-00-00 illustration -513. I can see a MIL-H-5593 but the rest is very hard to make out (bad resolution on my digital copy). Does anyone know what the part numbers are for all the hoses past the filter? Also, do you just buy by the foot and then cut to size, or can you buy these by the set? 

[PT20J]

If you look at the pages after the diagrams there are callouts for Stratoflex 193-10 and 193-6 hose. 193 hose meets MIL-H-5593. The dash number is the ID in 16ths of an inch. Stratoflex 193 is black. The hose in your pictures looks kind of like surgical tubing.

[Fritz1]

spruce sells vac tubing by the foot, that yellowish stuff really looks like surgical tubing which tends to collapse, good idea to get rid of all of it and clean what remains of the vacuum system the best way you can, replacing the vacuum pump might not be the worst idea either because it most likely ate some of the debris and they go without warning, dry vac pumps go 500h at best, if you don't have an electronic backup horizon get one, real life saver. I will not get rid of my vacuum system, independent source of energy, will drive an instrument when all electrical is out after EMP from nuclear blast or zombie apocalypse!

[CapPJ]

12 hours ago, Fritz1 said:

spruce sells vac tubing by the foot, that yellowish stuff really looks like surgical tubing which tends to collapse, good idea to get rid of all of it and clean what remains of the vacuum system the best way you can, replacing the vacuum pump might not be the worst idea either because it most likely ate some of the debris and they go without warning, dry vac pumps go 500h at best, if you don't have an electronic backup horizon get one, real life saver. I will not get rid of my vacuum system, independent source of energy, will drive an instrument when all electrical is out after EMP from nuclear blast or zombie apocalypse!

Thanks for the tips. Looks like this was missed during PPI and now annual ;(. I will definitely replace these and look into the vacuum pump as well.

[CapPJ]

16 hours ago, PT20J said:

If you look at the pages after the diagrams there are callouts for Stratoflex 193-10 and 193-6 hose. 193 hose meets MIL-H-5593. The dash number is the ID in 16ths of an inch. Stratoflex 193 is black. The hose in your pictures looks kind of like surgical tubing.

Got it! And I guess I need clamps on all terminations, which seems like I don’t currently have. Diagram calls for Corbin, can these be replaced by the screw type band? 

[PT20J]

10 minutes ago, CapPJ said:

Got it! And I guess I need clamps on all terminations, which seems like I don’t currently have. Diagram calls for Corbin, can these be replaced by the screw type band? 

I don't see why not. 

[A64Pilot]

Probably considered a sin, but I like to use Zip-ties for something like Vacuum hose, can’t crush things etc.

[Fly Boomer]

14 hours ago, Fritz1 said:

I will not get rid of my vacuum system, independent source of energy, will drive an instrument when all electrical is out after EMP from nuclear blast or zombie apocalypse!

I'm right there with you, brother!