Pressure and vac test

[Dan Forsh]

how difficult would it be to make a basic cylinder pressure tester? If I bought one of those pressure gauges where the needle stays at the maximum peak that went to 300 psi and took it to my local mechanical/hydraulic outfit, would it be as simple as asking them to make up a piece of pressure hose with a fitting to match the gauge on one end and matching fitting for the plug hole on the other, crank the saw and see where needle stops on the gauge? Probably too simple but thought i'd ask.

 

I think you're getting two different things confused here (or at least that's not what this thread was discussing). What you're describing is a compression tester, and I think these can be bought relatively cheaply to start with; probably not much in it by the time you've paid out for the parts to make one. I have one that I got second hand off Ebay and to be honest I don't really use it much. If a saw is that down on compression it's usually demonstrated sufficiently in other ways than needing to read the numbers.

 

If it is vac & pressure you are looking to test to check for air leaks, then I would start out with a compound pressure gauge that can read both + and - and then look at ways of generating pressure and vacuum. Bulb pump for a blood pressure cuff is okay for the pressure and others have said a large volume syringe for vac.

 

A few lengths of suitable tubing and some blank off plates and you should be able to knock up a rudimentary kit for a few quid.

Edited November 29, 2015 by Dan Forsh

[spudulike]

Yes, as above, you pressure check at around 10psi so a gauge reading 300psi is unsuitable. You can use the Gunson Low gauge and suitable methods of creating both vacuum and pressure with a suitable valve system as this gauge has suitable ranges in both positive and negative pressure!

[Dinosaw]

I've got one of those generic ebay specials (paid about £20 a few years ago) like this:

 

21PC Hand Held Vacuum Pressure Pump Tester Brake Fluid Bleeder Adapters Set Kit | eBay

 

They are pretty sh*t to be frank, and I usually spend as much time coaxing the pump/meter into action as I do doing the actual testing.

 

Thing is, there was (maybe still is) almost nothing available between the cheap and nasties and the expensive, but less nasty. Personally I don't use it enough to merit a posh one.

 

I've got one of these, it works very well. It's all metal and I haven't had any trouble with it at all. Cost about 27 quid,I think, about two years ago.