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#1 |
Designated A-hole!
Join Date: Mar 2003
Location: South Mississippi
Posts: 36,450
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Can I do this myself?
What do I need to build a cylinder leak down tester? I have a compression tester (borrowed) and some regulators laying around. Can I build my own, and if so how do I use it?
Thansk, krue
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"If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. ![]() We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck" |
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#2 |
Senior Member
Join Date: Jul 2003
Location: Indianapolis, IN
Posts: 1,277
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It should be fairly simple, the aviation community uses these on recip engines. Alll you are doing is comparing the air pressure loss in a cylinder against a known air pressure. You would need two pressure gauges and regulators. I remember using these in A&P school about 12 years ago, haven't used one since though.
If I can remember some of the aviation tool suppliers I will post them. Seems like Jegs and Summit sell them also. Dave |
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#3 |
Registered User
Join Date: Jul 2003
Location: north of Phx AZ about 30 miles
Posts: 698
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All I did was knock the ceramic out of a spark plug and welded an air chuck fitting to it. You don't really need a guage, just hook your air compressor to it at full blast. Then listen at the carb, muffler, or coolant fill neck. Your leakage will be apparant. Just be sure to bring the cylinder to TDC and wedge a breaker bar, on the crank nut, against the frame , or it will move the piston down, Rapidly! Don't ask me how I know that last part.
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Andy,Phx AZ '67 C-10 (Ahhh, done at last. Well there is that disk front end I want to put in and...) "23 C-Cab-sold '48 Ford 8N tractor(still working) '67 Scout(Now on the road) '70 MG B.-sold |
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#4 |
Registered User
Join Date: May 2003
Location: Shreveport LA
Posts: 3,170
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http://www.xs11.com/tips/misc/misc3.shtml
If you already have a compression tester, you could cut the hose & use the engine end instead of beating up an old spark plug, and use quick-disconnects so you could use it on both compression tester & leakdown testers. I built one a while back using a gauge on both sides of the regulator, but I didn't use a "damper valve". Maybe that's why my 70,000+ mile 305 showed only 2% leakdown. ![]() Let us know how it works. Last edited by jimfulco; 06-15-2004 at 11:47 PM. |
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#5 |
Registered User
Join Date: Feb 2004
Location: Massachusetts
Posts: 269
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I built my own by hollowing out a spark plug and brazing a compressor male quick release fitting to it, then I made a 3 foot peice of hose with a paint spray gun regulator (valve) with a guage on one end and a female quick release on the other. I set the big regulator on the compressor to 100 PSI, then set the little hose regulator so that the guage reads 0 psi while free flowing with the spark plug adapter attached. Pop out the adapter to stop the flow and the pressure should read 100 psi. Now screw the adapter in to a spark plug hole, and plug on the gizmo, and the guage will give you a relative reading somewhere between 0 and 100 psi. The actual PSI reading is not as important as consistency.
And Ya don't forget the breaker bar on the crank. 100 psi on your piston can develop a few hundred foot pounds of torque on the crank if the piston isn't at TDC.
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#6 |
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Join Date: Mar 2003
Location: South Mississippi
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Thanks, guys.
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"If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. ![]() We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck" |
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#7 | |
Registered User
Join Date: Feb 2004
Location: Massachusetts
Posts: 269
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Quote:
Most compession guage hoses have a check valve built in to the spark plug adapter, so it will not work for leak testing. As for hollowing out a spark plug, rather than busting it with a hammer sending shards of porcelan everywhere, just grind the rolled edge above the hex part. Once you grind away that part the whole porcelan peice will pull right out in one peice. I've made several adapters this way.
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#8 |
Designated A-hole!
Join Date: Mar 2003
Location: South Mississippi
Posts: 36,450
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btw that link is just what I needed.
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"If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. ![]() We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck" |
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