Homemade pressure testers

[KMB]

I've been getting ready for when I get my 044 together to test it for air leaks. I'll be buying the vacuum pump kit from Harbour Freight today and eventually following the procedure that Four Paws very nicely laid out in the 'Poorman's guide to Vacuum Testing' thread. I'd like to do a pressure test also and wanted to see (pictures please) what y'all use.

Kevin

 

[t_andersen]

Here are a few photos of my poor-man's kit. It's mostly made of cheap parts from Harbour Freight. The attachment plate is of alu with a brass fitting inserted with Araldite. I made an adapter both for the 064 and the 084. I can use it both for pressure and vacuum testing. Works great.

 

[Lakeside53]

Nice... Thanks for sharing Tom.

 

[bigbadbob]

That looks great, will need to build a similar one to test my 044 project, but that will be later. How is the barb held in the aluminum??

 

[KMB]

t andersen,
Thanks for posting that! That's the info I was looking for . I already have the pump unit that you have (also from Harbour Freight), and I know where I can get the other fittings and tubing. Where did you get your gauge? I wonder if I could use the gauge from the vacuum pump kit I bought yesterday from Harbour Freight or do I need a gauge that has the proper numbers for reading pressure values? Please forgive my ignorance. Once again...thanks.

Kevin

 

[t_andersen]

bigbadbob: I don't know the word "barb"? Do you mean the hose fitting? That one I glued into the alu with epoxy.

KMB: I believe that I bought the gauge at Harbour Freight (during a duty trip to the US). It handles both over- and underpressure. I think that it is made for fuel pump testing.

I couldn't find a no-return valve, but I use a small valve for garden irrigation that I close with one hand while I build up pressure with the other hand on the pump.

I think that you want to use a test pressure of about 1/2 atmosphere=7 psi=500 g/cm2=380 mm Hg

 

[KMB]

KMB: I believe that I bought the gauge at Harbour Freight (during a duty trip to the US). It handles both over- and underpressure. I think that it is made for fuel pump testing.

I couldn't find a no-return valve, but I use a small valve for garden irrigation that I close with one hand while I build up pressure with the other hand on the pump.

I think that you want to use a test pressure of about 1/2 atmosphere=7 psi=500 g/cm2=380 mm Hg

I found the answer to my question regarding if I needed a different gauge - which was yes I do. I found some on ebay and a search here on AS found this: http://www.arboristsite.com/showthread.php?t=32356&highlight=pressure+tester
I checked the SEARS website and they still sell the same gauge as what CaseyForrest used ($19.99), and the Harbour Freight website shows that they have one (on sale for $9.99 - regular $12.99), but it looks different then yours. If I would have know that I needed one I would have got it at Harbour Freight yesterday when I was in town :bang: :bang: .

I don't know if I understand you regarding a no-return valve. Would it go somewhere on/in the tubing/hose between the pump and the 3-way fitting that goes to the gauge? To hold the air pressure after it's left the pump?

My 044 service manual says 8.7 psi for pressure checking (and 5.8 psi for vacuum testing).

Kevin

 

[t_andersen]

The valve goes in right after the pump to prevent the air from leaking backwards through the pump during the test period. I paid around 10$ for my gauge and I believe that it was at HF. It is similar to this one but not the same: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93547.

 

[KMB]

The valve goes in right after the pump to prevent the air from leaking backwards through the pump during the test period. I paid around 10$ for my gauge and I believe that it was at HF. It is similar to this one but not the same: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93547.

Thanks for the info on the valve. I'll see what HD or Lowes or my local hardware stor has.
That's the gauge I hope to get on my next trip to town.

Kevin

 

[dieseldodge]

I was wondering if the cylinder leak down test kit would work, or would it not be good on that lower pressure. You could have different plates and just screw the fitting onto the plates for different saws? The gauge is from 0-100psi

jason

 

[Bowtie]

I was wondering if the cylinder leak down test kit would work, or would it not be good on that lower pressure. You could have different plates and just screw the fitting onto the plates for different saws? The gauge is from 0-100psi

jason

I think you will want a more accurate gauge since testing pressure is 7-8.5 psi depending on who ya ask, and maybe the saw. I tried a gauge like that, and I was concerned with overpressurizing the case. I dont know if thats a problem, but I was trying to get the right pressure according to what the stihl pro's recommend.

 

[dieseldodge]

Your probably right. I just thought that it might be easy, not to mention that its on sale for 29.00 normaly 59.00thruogh HF. I will half to try the other gauge.
jason

 

[cruxmon]

A pressure/vacuum kit using the MityVac 8500 with sealing plates and a spark plug adapter is available on eBay...search "2 Stroke Pressure & Vacuum Leak Down Engine"

 

[a. palmer jr.]

Don't need to spend much money on a pressure tester, just use the bulb off a blood pressure tester, some fuel lines, a tee fitting and a gauge. I think I have less than $5 in all of it..

 

[cruxmon]

Bulbs do not accurately test vacuum, only good for pressure testing (air).

 

[a. palmer jr.]

Bulbs do not accurately test vacuum, only good for pressure testing (air).

I have a vac/press. meter. I don't use the bulb for vacuum, pressure only..

 

[L34]

I use a large syringe.3 or 4 pumps with a non return valve gets me the pressure or vac I need depending which way around the non return valve is.
Chris.

 

[a. palmer jr.]

Lotta good ideas on here...I think I have some of those syringes around here also, use them mostly for epoxy glue..