Crankcase Pressure Testing

[RES]

Does anyone have a simple way to construct a pressure tester to check for crankcase leaks. I have a mityvac but that only produces vacuum. My other thought would be a bicycle pump but then I need a gauge and a check valve.

 

[Timothy]

blood pressure tester thing?

 

[Al Smith]

What he said,e-bay,cheap.

 

[Lakeside53]

.. it's called a bulb pump.

 

[RES]

Can you get enough pressure with this type of device?

 

[thompson1600]

Normally yes you can. I went to my local drug store and bought a $15 manual blood pressure device. Then cut the tubing off at the arm cuff. Worked great. Just have to find out what unit of measurement the blood pressure device is using and then convert that to PSI or BARS. You can use online calculators to figure that out. The one I bought went to about .48 bars when pumped all the way up. Stihl normally uses .5 bar for checking pressure, so it was real close.

Tom

 

[Lakeside53]

I've seen the entire bulb pump with valve and gauge specifically sold for small engine work for $29. Try mfgsupply.com or simialr.

 

[RES]

This is the only one I have found so far. A bit pricey
http://www.gokartgalaxy.com/vacuum_&_pressure_tester.htm

 

[Ax-man]

If your really serious about getting to the nitty gritty of engine problems with chain saws this pressure /vac testor is not out of line for the money. This looks like a good deal to me because you get two tools in one, plus those accesories to go with it, the accessories are not easy to come by.

The pressure tester alone that I have was $ 50 from Foley Belsaw. I also have one of those vac testers but it has no gauge on it unless I switch the gauge from one to the other, a real pain. I wouild be lost if I didn't have this pressure tester, especially for carb work, saves a heck of a lot of guess work not to mention money in buying parts if you miss diagnose a problem.

Thanks for the link, think I will get me a tester like that soon, my adaptor tips are getting a little worn. Another tool in the box never hurts.

Larry

 

[RES]

Here is another one from Mityvac
http://www.toolsource.com/ost/produ...5724&mscssid=8FT6KWWPDX5G9HC17BMP32MQ7P67BWW7

 

[treefrog359]

pressure test

try dumping a little 50:1 gas in the intake port so it fills the crank case. if there is a leak the gas will find it and run out. then clean all the gas out and let it dry out befor you run it.

 

[Simonizer]

Here is another one from Mityvac
http://www.toolsource.com/ost/produ...5724&mscssid=8FT6KWWPDX5G9HC17BMP32MQ7P67BWW7

This is the tool you need. Don't play around. You can make plates for exhaust and intake. For really bad leaks I use a regulator and a shut-off valve. This saves pumping and seeing no pressure reading. Never exceed 20 PSI.(There is no need.)

 

[RES]

According to the Stihl manuals they test with the piston at top dead center and feed air into the intake manual with a special adapter. Is there any disadvantage of testing with the piston down and feeding air into the sparkplug hole? The mityvac has its gauge on the pump. There is no way to shut off the pressurized air with a valve and monitor the pressure, unless you add another valve and gauge.

 

[Lakeside53]

It doesn't matter really where the piston is so long as there is a path around it to the crankcase or cylinder... You can feed pressure anywhere so long as you block off all the other ports, so yes, you can feed into the plug but you still have to seal off the intake, impluse and exhaust. Don't exceed 9psi... for any test...

 

[Fish]

I have a rubber tip on my air gun, 140 psi on my compressor, finds the air leaks quickly, removes the seals too.

 

[Al Smith]

I have a rubber tip on my air gun, 140 psi on my compressor, finds the air leaks quickly, removes the seals too.

Well ,that's a novel idea.

 

[p38lightning]

I made one with a pressure cooker guage, a Tee fitting and a bubble pump that I ordered from a homebrewing supply store. I just cut plates out of thin malable steel, I even cut gaskets to put behind it and it works fine. The only thing is you have to seal the threads off on the cooker guage with JB Weld or something similar because they are not pipe threads.

 

[Locoweed]

Fish, 200 psi might remove the flywheel also. Save the cost of a puller

 

[Ax-man]

I have a rubber tip on my air gun, 140 psi on my compressor, finds the air leaks quickly, removes the seals too.

Is this another shop tip of the day from Fish. I got to try this on a junk engine and see how it works.

Larry