Poorman's guide to Vacuum Testing

[pdqdl]

An update !

I was referred to this post by another helpful member, and I thought I would update this thread.

I made a Word document that captures the images and text; now you can print it and save it for future reference. Unfortunately, I cannot upload it to AS, the file is too big!

I could break it into two parts, but that seems like a waste of time. Surely there is a better way. I tried zipping it, but there was not much difference in size.

Any suggestions on how this might be done?

 

[046]

here's the lucky way.... craigslist.. $50
betcha that won't happen again...

 

[teacherman]

I have found that Gorilla® brand duct tape is a quick and effective port sealer for this purpose. Goes right on the rubber manifold and the exhaust port of the cylinder. Clean area first, press it on hard, and it holds. Little or no residue deposits left behind. Nothing to fit or bolt.

(just waiting for Spacemule to twist these words around......):greenchainsaw:

 

[teacherman]

I was referred to this post by another helpful member, and I thought I would update this thread.

I made a Word document that captures the images and text; now you can print it and save it for future reference. Unfortunately, I cannot upload it to AS, the file is too big!

I could break it into two parts, but that seems like a waste of time. Surely there is a better way. I tried zipping it, but there was not much difference in size.

Any suggestions on how this might be done?

Take a screen snapshot or two or three, and save them as jpegs and post them so they pop up automatically. Macs use Preview for the screenshot, not sure how a PC does it. Pretty quick and easy.

Or, anyone wishing to print it can do the same with the original post.

 

[stihl only]

As was mentioned here before, make sure to do both a pressure and vac. Just because it will hold vacuum, doesn't guarantee it will hold pressure. Had an 038 MAG II here the other day that would hold vacuum for a month of Sundays, but the clutch side seal was leaking so bad you couldn't even pump the thing fast enough to get a reading.

For a real problem saw like this one, what Lake suggested with the regulator and a compressor is the ticket!

 

[JONSEREDFAN6069]

thanx for the tip, gonna put it to use on my 630.

 

[teacherman]

As was mentioned here before, make sure to do both a pressure and vac. Just because it will hold vacuum, doesn't guarantee it will hold pressure. Had an 038 MAG II here the other day that would hold vacuum for a month of Sundays, but the clutch side seal was leaking so bad you couldn't even pump the thing fast enough to get a reading.

For a real problem saw like this one, what Lake suggested with the regulator and a compressor is the ticket!

I thought it was the other way around. Thanks for clearing that up.

 

[AOD]

Some leaks/seals may hold under a vacuum but not under pressure, and vice versa. In A/C systems, they're pressurized to 200# to check for any leaks and hen drawn into a deep vacuum, at least 25" Hg, before being charged with refrigerant. These are far more extremes than anything found in the small engine world. Is a little leaking in a crankcase seal to be expected. In open drive refrigeration and A/C compressors a crankshaft seal is used and these can at best be called "leak resistant", they all leak some and its only a matter of time until they need replacement.

 

[heimannm]

Thanks 4 Paws, should be just the inspiration I needed to go ahead and get the pump.

I actually have two of the McCulloch 10 series parts kits for pressure/vacuum testing with the various plates, rubber seals, bushings, fittings, etc.

I also have a very suspicious John Deere/Echo saw on the shelf right now, a little testing should help conclude where the issues are or perhaps are not.

Mark

I assume if you don't remove and block the muffler you have to make sure the piston has the exhaust port covered?

 

[pdqdl]

Take a screen snapshot or two or three, and save them as jpegs and post them so they pop up automatically. Macs use Preview for the screenshot, not sure how a PC does it. Pretty quick and easy.

Or, anyone wishing to print it can do the same with the original post.

Well... sure. But that doesn't serve the purpose I started with: Since printing from a thread gives clutter, tiny print, and poor control over the output, I tried to give folks something they could save and re-use.

There is no real gain in re-posting what was well done to begin with. By the way, I have incorporated some of the very good comments added by other people, so this file would be a small improvement on the original post.

If anyone wants this, private message me and I'll send it along. (Unless I get thousands of requests!)

 

[skid row]

As was mentioned here before, make sure to do both a pressure and vac. Just because it will hold vacuum, doesn't guarantee it will hold pressure. Had an 038 MAG II here the other day that would hold vacuum for a month of Sundays, but the clutch side seal was leaking so bad you couldn't even pump the thing fast enough to get a reading.

For a real problem saw like this one, what Lake suggested with the regulator and a compressor is the ticket!

:agree2: :agree2:

 

[briantutt]

I was referred to this post by another helpful member, and I thought I would update this thread.

I made a Word document that captures the images and text; now you can print it and save it for future reference. Unfortunately, I cannot upload it to AS, the file is too big!

I could break it into two parts, but that seems like a waste of time. Surely there is a better way. I tried zipping it, but there was not much difference in size.

Any suggestions on how this might be done?

Send the file to me at [email protected] I will get it up as a pdf.

 

[Evan]

to the the top.

i did search and this theard didnt come up. not sure what good the search function is when old threads like this dont come up

bet it does now

 

[briantutt]

I was referred to this post by another helpful member, and I thought I would update this thread.

I made a Word document that captures the images and text; now you can print it and save it for future reference. Unfortunately, I cannot upload it to AS, the file is too big!

I could break it into two parts, but that seems like a waste of time. Surely there is a better way. I tried zipping it, but there was not much difference in size.

Any suggestions on how this might be done?

:hmm3grin2orangeONE:hmm3grin2orange:

 

[pdqdl]

That's great.

Four paws' excellent technical instructions, my own pretty good compilation of the notes he posted, and your nice conversion to a PDF.

Teamwork in action.

You guys that read this need to save that PDF for the day when you need it.

 

[Brian VT]

I just got a Mighty-Vac MV7000 at Sears for $35. I comes with all sorts of fittings, etc. I didn't need to buy any pieces/parts. Works great.
Even better news is that my "problem saw" (MS360 Pro) seems to be tight. The mystery continues, but I'm narrowing down the suspects.
Good thread here. So much great info on this site.

 

[milkie62]

working or not

I picked up the tester from HF a couple of weeks ago.I put my finger over the fitting and gave it a few pumps but did not pull any vacuum on the guage.Do I assume the unit is no good ?

 

[ric5141]

I did the vacuum test on a Husky that was giving me lots of issues. Could not get any vacuum. Cobbled some more fittings (my compression tester has a screw in plug adapter with 1/4 coupling...sweet) put the bicycle pump and a fuul pump pressure tester on it and couldn't get it to hold any. Popped the flywheel and looked through the seal at the crank bearing! Man I have never seen a seal ripped up like that.

Thanks for the info and tech advice.

BTW Bearings and seals (units) are on their way

 

[Arrowhead]

I picked up the tester from HF a couple of weeks ago.I put my finger over the fitting and gave it a few pumps but did not pull any vacuum on the guage.Do I assume the unit is no good ?

I would say its junk.

 

[stihl_]

Vacuum Tester

You are lucky to get the vacuum tester for $17, they are about $170 in Australia.