Gearcase pressure tester

[outbdnut2]

Looking at a nice homemade pressure tester in another recent post got me to thinking. I’ve been going to make a tester for a long time. I have an automotive radiator/coolant system pressure tester I bought 30 years ago and haven’t used for many years, and I’m thinking of adapting that for gearcase pressure. It has a hand pump, checkvalve, and a gauge and is made to go from 0 to 30 pounds.

It looks nearly identical to the photo below (from O’Reilly auto’s website) – I’m thinking all I have to do is replace the radiator cap on the end of the hose with a fitting to thread into the lower gearcase drain hole. Maybe use compressed air quick-connect fittings to switch back to the radiator cap. Has anyone done that? Your thoughts?
Dave

[nj-boatbuilder57]

Sure seems like it would work.

[chris-p]

Yes would work fine.

I made mine from a tire inflator/gauge as in the picture below. I simply cut off the end that attaches to the tire and installed one from the link below it that fits into a gearcase.

https://www.ebay.com/itm/CDI-551-34TN-T … 1438.l2649

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[rco]

That’s what I did to make mine. I added quick connects so I could go back and forth from auto to outboard testing. I drilled a 3/8" NC stud to let the air through and threaded that into a male quick connector with a thick rubber washer to seal it to the gear case. Works great, and the 3/8 thread fits OMC, Merc, and Chrysler at least.

[Steve D]

quote outbdnut2:

I have an automotive radiator/coolant system pressure tester I bought 30 years ago and haven’t used for many years, and I’m thinking of adapting that for gearcase pressure.

I also converted something similar to use for gear case testing and dual hose tank pressure testing.

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[rjoynt]

I called Stevens a few years ago and bought a rebuilt tester for half price. Great folks to work with. Then recently bought the vacuum version on eBay at a great price.

[outbdnut2]

Thanks guys, I think I’ll convert my radiator tester and it never occurred to me to use it to test pressure tanks.
Dave

[bob-d]

Steve D, what pressure do you use to check the two line tanks?
Bob D

[Steve D]

Bob, I think I remember someone on here saying that these tanks run on only 3-4 lbs. but I usually test at around 5-6. That’s enough to detect a leak and then spray soapy water to isolate it.

[fleetwin]

quote rjoynt:

I called Stevens a few years ago and bought a rebuilt tester for half price. Great folks to work with. Then recently bought the vacuum version on eBay at a great price.

The folks at Stevens are very nice, they answer the phone, and return calls. A rarity these days. Stevens also sells the fittings that screw into the gearcase separately at a very reasonable price. The key to any pressure vacuum gage is a good gage that reads low enough for this work, and that doesn’t have its own internal leaks….Nothing more frustrating then trying to find a gearcase leak only to discover that the leak is actually in your pressure tester rig….

[Author]

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