86 Quad R
11-14-2006, 01:45 PM
the question has been asked or come up quite often recently. HOW to do a leak down test or HOW to make a tester? so i thought i would post a sticky (not sure how to do that. so here's a post)on the subject.
you'll need to borrow or make your own tester such as this one....
http://i793.photobucket.com/albums/yy213/86-Quad-R/Leak%20Down%20Tester/IM000597.jpg
to make one you'll need:
1. a blood pressure bulb- can be gotten at most any drug store
2. a small brass nipple- can be gotten at local auto parts store. it is to be threaded into either the end or the side of the pvc cap.
3. a low pressure gage- can be gotten at local weld/tool supply. it is to be threaded into the pvc cap aswell.
4. a short stick of pvc pipe(that'll fit the intake boot) and a cap(to be glued onto the pvc pipe.
5. a peice of hose (3/16 to 5/16" will do)
process: (although the following instructions are based one a totally sealed engine, it can be performed on a bench build prior to installation of the stator and clutch covers.
the tester clamps into your intake boot and allows you to test the whole system.
you'll need to make a gasket that'll clamp between the exhaust flang and engine. my favorate is to use an inner tube from a bicycle.
as a rule of thumb, pump the system up (no more than 10 psi's and allow to set for at least 10 minutes.
during this time you spay the external engine with a soap/water mix to check for leaks(any leak will bubble up like a foam). this includes the crank case vent tube aswell.
ideally you want the psi's to remain constant for the 10 minutes but a pound per minute is acceptable but not to exceed 5 lbs.
you'll need to borrow or make your own tester such as this one....
http://i793.photobucket.com/albums/yy213/86-Quad-R/Leak%20Down%20Tester/IM000597.jpg
to make one you'll need:
1. a blood pressure bulb- can be gotten at most any drug store
2. a small brass nipple- can be gotten at local auto parts store. it is to be threaded into either the end or the side of the pvc cap.
3. a low pressure gage- can be gotten at local weld/tool supply. it is to be threaded into the pvc cap aswell.
4. a short stick of pvc pipe(that'll fit the intake boot) and a cap(to be glued onto the pvc pipe.
5. a peice of hose (3/16 to 5/16" will do)
process: (although the following instructions are based one a totally sealed engine, it can be performed on a bench build prior to installation of the stator and clutch covers.
the tester clamps into your intake boot and allows you to test the whole system.
you'll need to make a gasket that'll clamp between the exhaust flang and engine. my favorate is to use an inner tube from a bicycle.
as a rule of thumb, pump the system up (no more than 10 psi's and allow to set for at least 10 minutes.
during this time you spay the external engine with a soap/water mix to check for leaks(any leak will bubble up like a foam). this includes the crank case vent tube aswell.
ideally you want the psi's to remain constant for the 10 minutes but a pound per minute is acceptable but not to exceed 5 lbs.