pressure testing ,, hows it done?
- Thread starter minet
- Start date
to clarify, are you asking about coolant system or DD case? there has been talk recently of pressure testing the "case" to check for internal gaskets leaking coolant by which i what i assume you meant but i know cat also recomends pressure testing DD case w/ vent plugged to make sure its not leaking fluid. and then there is always compression test on cylinders also.....
sounds like a compression check on the cylinders is what your after. you can buy a pressure gauge that threads into head where spark plugs go (pull pipe to get it in there may as well since you need to both cylinders). i try to do it on a warm motor. kill switch off, pull it over 10 times with throttle open so it gets plenty of air and read off pressure gauge. do other cylinder they shouldn't vary by more than 10% less is better. not sure what sled you have so i don't know what psi you should be looking for.
chit buddy thats what i thought you wanted but the seals/gaskets your talking about basically are the coolant system. head and jugs/lower case gaskets keep coolant out of the cylinders and crank. i haven't done it yet but its on the list for this summer so hopefully someone else can chime in here. as far as i understand if the thermostat is closed to isolate the case you want to pressurize the system from the coolant supply line from the reservoir. you might need to block off or maybe even put the pressure gauge on that line that returns from head to coolant reservior. this is a relatively low pressure test also. are you loosing coolant or something?
He is talking about doing a leak-down test. They make a leak-down tester, which is similar to a compression tester, but allows you to pressure up the cylinder and see if you have any gaskets or seals that are leaking.
http://en.wikipedia.org/wiki/Leak-down_tester
Harbor Freight tester
Jegs tester
http://en.wikipedia.org/wiki/Leak-down_tester
Harbor Freight tester
Jegs tester
Minet
reading your post, I take it that your engine is running and in the sled. I also take it that you want to check the crank seals, center seal for vacuum leaks.
If this is correct, and easy way to check the seals is run the engine at normal operating temperature, use a propane torch (NOT BURNING) or staring fluid, and put the tip down by the suspected seal with the propane turned on. If you have a leaking seal it will suck in the propane or starting fluid and raise the engine RPM. You can do this checking any vacuum leak also on cars. This is a quick and easy way to check. The more elaborate way is use a hand pump and leak down gauge. By pumping air ( low pressure ) into crankcase and watching how long it takes to bleed down. This will check seals, gaskets, and rings. Engine has to be caped off at exhaust outlet and intake. The latter is the way engine shops will do it.
reading your post, I take it that your engine is running and in the sled. I also take it that you want to check the crank seals, center seal for vacuum leaks.
If this is correct, and easy way to check the seals is run the engine at normal operating temperature, use a propane torch (NOT BURNING) or staring fluid, and put the tip down by the suspected seal with the propane turned on. If you have a leaking seal it will suck in the propane or starting fluid and raise the engine RPM. You can do this checking any vacuum leak also on cars. This is a quick and easy way to check. The more elaborate way is use a hand pump and leak down gauge. By pumping air ( low pressure ) into crankcase and watching how long it takes to bleed down. This will check seals, gaskets, and rings. Engine has to be caped off at exhaust outlet and intake. The latter is the way engine shops will do it.
Pressure Testing Engine
1. Test the engine for air leaks using the following
procedure and Compression/Pressure Tester Kit
(p/n 0644-366).
a. Install a plug into each intake-manifold port
and tighten the flange clamps securely.
b. Place a rubber plug and cover on each exhaust
port and secure.
c. Connect the tester pump to an impulse fitting
on the crankcase; then plug any remaining
impulse fittings and pressurize the crankcase to
8 psi and close the valve.
AN128D
d. Monitor the pressure gauge. The pressure must
not drop at a rate of more than 1 psi per minute.
e. If the pressure drops faster than specified,
inspect for an air leak with soapy water or by
completely submerging the pressurized engine
in clean fresh water. Repair as needed.
1. Test the engine for air leaks using the following
procedure and Compression/Pressure Tester Kit
(p/n 0644-366).
a. Install a plug into each intake-manifold port
and tighten the flange clamps securely.
b. Place a rubber plug and cover on each exhaust
port and secure.
c. Connect the tester pump to an impulse fitting
on the crankcase; then plug any remaining
impulse fittings and pressurize the crankcase to
8 psi and close the valve.
AN128D
d. Monitor the pressure gauge. The pressure must
not drop at a rate of more than 1 psi per minute.
e. If the pressure drops faster than specified,
inspect for an air leak with soapy water or by
completely submerging the pressurized engine
in clean fresh water. Repair as needed.
