Making a pressure tester for Mercruiser outdrive

[crazy charlie]

I'm not accustomed to making tools or gages.Saw a YouTube video that made it look pretty simple using a brake bleeder..Im thinking I can use this compresser hose with gage that came with a high end model vehicle from approx 40 years ago.The vehicle had a built in compresser.Never used it ,been taking up space in my toolbox for a loooong time.Im thinking the barbed end gets the outdrive filler connector and just have to figure another connector for the portable tire inflator I plan on using.Both ends right now were made to screw on to a tire valve stem.If I can figure out a connector for the inflator side ,I think it should work..??? Charlie

 

[Dubed]

I'm not accustomed to making tools or gages.Saw a YouTube video that made it look pretty simple using a brake bleeder..Im thinking I can use this compresser hose with gage that came with a high end model vehicle from approx 40 years ago.The vehicle had a built in compresser.Never used it ,been taking up space in my toolbox for a loooong time.Im thinking the barbed end gets the outdrive filler connector and just have to figure another connector for the portable tire inflator I plan on using.Both ends right now were made to screw on to a tire valve stem.If I can figure out a connector for the inflator side ,I think it should work..??? Charlie

I used a cooling system pressure test kit and adapted the hose to the drive with a fitting. Pump up to pressure, and let her sit overnight. Very easy

 

[stresspoint]

a cheapo bicycle pump and a couple of fittings is all i use , don't over think it you only need a few PSI and it needs to stay stable for an hour or 2,

even a squirt bottle with dish detergent squirted around general areas after pumping up will soon show a leak if there is one most times..

 

[crazy charlie]

I figured since I already have this(for 40 years) I might as well use it.just need a fitting similar to a tire valve stem and that should do it.Charlie

 

[Scott Danforth]

I bought a Mityvac MV8500 years ago

does both pressure and vacuum

comes with adapters to test cooling systems, brake systems, bleed brakes, etc. I already had the fittings for the gear boxes (from the gear oil pump), so i use on them too.

MV8500

SILVERLINE ELITE HAND PUMP KI

shop.mityvacparts.com

about $80 on amazon.

 

[stresspoint]

I figured since I already have this(for 40 years) I might as well use it.just need a fitting similar to a tire valve stem and that should do it.Charlie

yea good point its there why not make something of it.

i went to the trouble of brazing a old tire valve to a used drain plug , clip the bycicle pump on and pump up .

one thing to add , the recommended test is around 20 psi from memory ,i now only go up to 10 or 12 since i popped a prop seal on a old Evinrude

 

[crazy charlie]

yea good point its there why not make something of it.

i went to the trouble of brazing a old tire valve to a used drain plug , clip the bycicle pump on and pump up .

one thing to add , the recommended test is around 20 psi from memory ,i now only go up to 10 or 12 since i popped a prop seal on a old Evinrude

The only brazing I am capable of doing is on a Porterhouse...

 

[JASinIL2006]

I think 15 psi is max... in actuality, 11-15 psi is sufficient. Seals can definitely be popped if you over-pressurize.

I follow the procedure in post #21 on this thread:

Drive Pressure/Vacuum Check

Re: OD Presure Test Re: OD Presure Test The service manual doesn't even mention pressure testing, here is from a 1998 Mercruiser training manual.

forums.iboats.com

 

[bruceb58]

I decided against making my own. Just bought the professional tools from Stevens. I know people that mess around with their DIY setup WAY too much. I just want an accurate tool that works every time.

You definitely want a gauge that has a midpoint pressure of around 15 PSI so you can actually see if it is leaking or not. The gauge in the OP is WAY too high

Gearcase Pressure Tester | Stevens Instrument Company

www.stevensinstrument.com

Gearcase Vacuum Tester | Stevens Instrument Company

www.stevensinstrument.com

 

[stresspoint]

I decided against making my own. Just bought the professional tools from Stevens. I know people that mess around with their DIY setup WAY too much. I just want an accurate tool that works every time.

You definitely want a gauge that has a midpoint pressure of around 15 PSI so you can actually see if it is leaking or not. The gauge in the OP is WAY too high

Gearcase Pressure Tester | Stevens Instrument Company

www.stevensinstrument.com

Gearcase Vacuum Tester | Stevens Instrument Company

www.stevensinstrument.com

while i agree it is nice to have the correct tool for all jobs , some of us have to improvise and use what is available to us at the time of doing a job .

if i had to buy a special tool for every job i do in the shed there would be thousands of special tools that would be used once then hung up or shelved never to be used again.

when people work on everything and anything we tend to improvise and make our own tools rather than buy specific for a job.

i have draws full of special tools bought and made , some i cant even remember what they were for they have been there that long.

which brings thought to a new thread just for fun"" guess what the tool is for "

 

[Dubed]

while i agree it is nice to have the correct tool for all jobs , some of us have to improvise and use what is available to us at the time of doing a job .

if i had to buy a special tool for every job i do in the shed there would be thousands of special tools that would be used once then hung up or shelved never to be used again.

when people work on everything and anything we tend to improvise and make our own tools rather than buy specific for a job.

i have draws full of special tools bought and made , some i cant even remember what they were for they have been there that long.

which brings thought to a new thread just for fun"" guess what the tool is for "

Thats why I use my cooling system pressure tester. I already have it, so I just swap the hose and fitting when I want to attach it to the drive. The hand pump and gauge works perfectly for the job.

 

[crazy charlie]

You definitely want a gauge that has a midpoint pressure of around 15 PSI so you can actually see if it is leaking or not. The gauge in the OP is WAY too high

Gearcase Pressure Tester | Stevens Instrument Company

www.stevensinstrument.com

Gearcase Vacuum Tester | Stevens Instrument Company

www.stevensinstrument.com

The gage should be fine as the large numbers are not psi.the psi numbers are much harder to see in the pic but go up to 100psi.If I pump up to 15 and leave overnight,I should be able to see a leak or not.Right?? Charlie

 

[bruceb58]

The gage should be fine as the large numbers are not psi.the psi numbers are much harder to see in the pic but go up to 100psi.If I pump up to 15 and leave overnight,I should be able to see a leak or not.Right?? Charlie

I know what it goes up to...you want a gauge that goes up to 30 PSI so that the pressure you are interested on is right in the middle of the gauge capabilities.

 

[bruceb58]

while i agree it is nice to have the correct tool for all jobs , some of us have to improvise and use what is available to us at the time of doing a job .

if i had to buy a special tool for every job i do in the shed there would be thousands of special tools that would be used once then hung up or shelved never to be used again.

when people work on everything and anything we tend to improvise and make our own tools rather than buy specific for a job.

i have draws full of special tools bought and made , some i cant even remember what they were for they have been there that long.

which brings thought to a new thread just for fun"" guess what the tool is for "

To me, buying a tool to make my life easier is priceless. I also figure, the money I spend on tools is basically free vs having someone else work on it so the cost of the tool becomes pretty insignificant over time.

 

[stresspoint]

The gage should be fine as the large numbers are not psi.the psi numbers are much harder to see in the pic but go up to 100psi.If I pump up to 15 and leave overnight,I should be able to see a leak or not.Right?? Charlie

over night should be more than ample time for a leak to show.
as posted a squirt bottle with dish soap and water will show most leaks .
you are looking for the not so obvious using the pressure gauge so about an hour should do the trick.

if your oil was clear with no sign of sludge then you should have no concerns.

now you need to rig to pull a vacuum, some of the seals in the gearbox work both ways,
when the gearbox gets hot the contraction can suck water in if a seal is dodgy
.
again , if there was no sign of water intrusion then you have nothing to be concerned about.

if you want to rig something to test for peace of mind
a shop vac with some 1/4 id tube taped into the nozzle , ( the hose that you tested the pressure will work) will pull a minimal vacuum , once you get a little vacuum some vice grips on the hose will hold it.
rigged up fittings and hoses from the pressure pump taped into the vac nozzle work for me.

FWIW , the most common thing i see when it comes to leaks in gearcases is the O rings on the plugs , surveyor's , unscrew them to check for water and dont bother to replace the Oring .
had one guy use an impact screw driver on a gear case plug once , he got a walking ticket as he was not touching my boat again.

 

[04fxdwgi25]

The gage should be fine as the large numbers are not psi.the psi numbers are much harder to see in the pic but go up to 100psi.If I pump up to 15 and leave overnight,I should be able to see a leak or not.Right?? Charlie

30 psi gauge is only $9.00 at Ace hardware. I just bought one to test someone else's cooling system to verify a freeze crack.

 

[crazy charlie]

30 psi gauge is only $9.00 at Ace hardware. I just bought one to test someone else's cooling system to verify a freeze crack.

ACE hardware??? You can even buy a paintbrush at ACE for under $10. Anyway.....like i already stated,I have this hose and gage already so thats the main reason I plan on using it.I need more stuff in may garage like a hole in the head.Right now my only part issue is a connector to inflator or hand pump.Charlie

 

[Dubed]

Amazon has Schrader valve /hose barb fittings pretty cheap. Not sure on your hose size

 

[crazy charlie]

Amazon has Schrader valve /hose barb fittings pretty cheap. Not sure on your hose size

Hose fitting is made to screw onto a tire valve stem so im gonna need something like a valve stem with threads on both sides.Charlie

 

[matt167]

When I built my tester. I took a $10 bike pump. Pulled the scrader end off the hose. Installed the oil fitting from a $6 gear lube pump. They are both barbed fittings with the same hose size . Easy cheap tester