Date:Jan. 15, 2023


Brief Description:

After cranking down on the worm gear hose clamps every time I have the cowl off to stop drips from coming out of the oil return lines I decided there must be a better method.  Putting an 8mm socket on an extension is not that big of a deal but the clamps just seem to dig deeper into the hose material.  As the hose gets hot/cold and expands/contracts the clamps do not adjust their clamping pressure resulting in the drips I have seen.  A quick search on VAF and I came across the idea of using spring-band clamps instead of the worm gear clamps. 

After a cursory search for spring band clamps on Amazon I saw a plethora of inexpensive, various sized clamp kits although none made me feel comfortable.  They all seemed a bit “cheap”.  I searched on McMaster-Carr and found some clamps with product specs listed and opted to purchase the clamps they offered that had a higher temp rating.  They are quality after handling them.

You can see from the pictures what the stock clamps did to the hose as they dug into it.  The beefier replacement hose and spring clamps are a far superior solution.  I used a set of special needle nose to install the clamps. 

Install Method:  Cut hose length exactly as to what came off.  Slide new rubber hose onto rigid return line to the same spot old one was removed.  Clock band clamp that goes on rigid hose so it is out of the way from the bottom of the hose/engine.  Temporarily install second band clamp onto hose next to the first one.  Maneuver assembly onto engine and check that the flared end of the rigid line is mating with the AN fitting on the cylinder and will require no pressure at union to make connection.  Make sure that he other end of the assembly with the new rubber hose has the hose touching the base of its fitting that is on the case.  Next step is to get needle nose pliers into position and compress band clamp and “time” the clamp so that it does not touch the engine, baffling, etc.  I  had to remove the #2 cylinders intake tube to access the return lines.  Everything else stayed on the engine.  The needle nose pliers worked well except it was tricky to get them to bite on the clamps.  I might buy a specific set of clamp tools but all the ones I have seen have very bulky ends so it may be necessary to modify the ones I have to work better next time.  

See parts listed below.

These clamps from McMaster-Carr:

7329K12 Constant-Tension Spring-Band Clamps for Firm Hose and Tube (black-phosphate steel)

McMaster-Carr P/N: 7329K13 (zinc-plated steel – what I ordered)



This hose from Aircraft Spruce:


Part #: 6000-6
Mfr Part #: 8507-21296 BULK


P/N shown but ordered 2′.

P/N and quantity ordered.

New method of putting cardboard on work bench and writing on it to keep track of things.  I like it a lot.  Tools labeled for future reference.

My attempt to keep the ends square and true.  Wear safety glasses if you try this!

Example of old hose that got replaced.

New hoses and band clamps installed ready to head to engine.

Red/Black handles on left of exhaust and needle nose shown on right of exhaust.


Band clamps timed so that they don’t touch anything.

Pliers that I used.  They worked but will look for something with a better suited end to grab clamps (or roll my own upgrade).