Hey People, I made my own Leak down tester today after looking around shops and not finding one!!! Just wanted to share this with everyone so those of you who want to can make one for around $35.

Went to Sears and asked for part 282-16025 which is a regulator with a small ****(same one they use on the snap on leak down testers) to adjust the pressure. it also has a small gauge with it also!! after buying that I got the female and male coupling ends and bam!! I had myself an official Leak down tester!! well, i have to use the hose part of my compression tester but hey, at least i built this little kick *** part for only $35!!! i'll be testing this bad boy this weekend so wish me luck!!

picture from website i got from: special thanks to http://www.650motorcycles.com/LeakDownTester.html

 

Nice idea but how do you measure the air coming in?

 

Probably at the compressor's regulator. Not as accurate, but perhaps close enough.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">Nice idea but how do you measure the air coming in?</TD></TR></TABLE>


well it said on the website: you adjust the air coming with with the ****(the black thing with the red lining) to 100 psi., close the **** and watch the gauge to see if there's a drop. I'm gonna assume this idea has to work. this is the same regulator as on air compressors. Let's just hope this works out

 

It'll work, I made my own too. Did you use a damper valve on yours?
The fun part is finding the true TDC for each piston
because if its not, the motor will crank foward or backward as you pressurize the cylinder. Doing a leakdown is how I found out my crank pulley marks were way off.

Pressurizing each cylinder with regulator set at 100psi..
my motor at 194,080 miles checked out:
#4 - 98psi
#3 - 96.5psi
#2 - 97psi
#1 - 98psi

I heard a slight hiss coming from the valve cover. Typical worn valve stem seal(s).

 

Nice!

 

[QUOTE=Quick 200k Mile Motor]It'll work, I made my own too. Did you use a damper valve on yours?
QUOTE]


Damper valve?? not sure...whatever is pictured is what i have. think it'll work?

 

It'll work, but you might get readings that fluctuate.
The damper valve could be anything that provides restriction between the regulator and gauge. You get a steady reading with it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Quick 200k Mile Motor &raquo;</TD></TR><TR><TD CLASS="quote">It'll work, but you might get readings that fluctuate.
The damper valve could be anything that provides restriction between the regulator and gauge. You get a steady reading with it.</TD></TR></TABLE>


hmm....never thought of that. i'll have to look around Menards or Fleet Farm and try to find something sorta like that. Thanks for the new idea!

 

I still don't understand how you will read your % of leakdown. If the one gage is for pressure in reading, you would need another for % out, I think. Otherwise, you would have to assume that your pressure in is always exactly 100 lbs or you would get false readings. Am I missing the point? I think you need 2 gages like the one I bought from Summit.

 

not a problem, just to give ya an idea this is basic procedure:

First, your compressor must be able to maintain 110psi (150psi max) tank pressure.
Connect the tester to the tank.
On the tester, adjust the regulator **** until the gauge on the tester reads exactly 100psi.

With the piston at TDC, when you connect the tester to spark plug hose, the cylinder gets pressurized and the % of pressure lost is presented on the gauge in psi (for example 98psi means 2% loss) because you put in 100psi in..
and 2psi was lost through: headgasket, valve seats, valve stem seals, piston rings, or tiny hole in piston etc..

An easy way to pin point the problem is by listening.
For example if you hear hiss coming from your coolant system, your headgasket is leaking.

 

oh, you have the Dual gauge tester..

one gauge is for monitoring of the input air line pressure, and the other gauge just gives a larger window of accuracy, because most 100psi gauges (including the small ones) have an increment scale that is not large enough to look at for accuracy.

 

how long do you allow for the pressure to drop?like, how long do you leave the tester connected for until you know its lost the right amount?

 

You can leave it pressurizing the cylinder as long as your tank is still supplying above 110psi (150max). I never leave it in there for more than 30sec, by then you should know where the hiss noise(s) are coming from.

 

I guess that would work , but I think you would need a regualter to make sure the pressure comming in stays excatly 100 psi.
I still like the two gauge set up, Or the moroso one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Quick 200k Mile Motor &raquo;</TD></TR><TR><TD CLASS="quote">You can leave it pressurizing the cylinder as long as your tank is still supplying above 110psi (150max). I never leave it in there for more than 30sec, by then you should know where the hiss noise(s) are coming from.</TD></TR></TABLE>
if youre constantly putting air in the cyl, how do you know when its losing air?

 

i got a gauge from harborfreight with coupling for 6.99 and the spark plug hose adapter for 10bucks at pep boys = $17

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lazerus &raquo;</TD></TR><TR><TD CLASS="quote">to expand upon things, you could put in a one way valve after the connection on the guage, so you could pressurise the cyl, then unplug the air source, then measure your leakdown.</TD></TR></TABLE>

i dont think that would work. you need the air source to give you a continuous feed, otherwise it would just keep leaking until no air is left.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridvteceg &raquo;</TD></TR><TR><TD CLASS="quote">
if youre constantly putting air in the cyl, how do you know when its losing air?</TD></TR></TABLE>

it is always losing air. 1-2% leakage is normal. its not like a bottle where you put in 100oz of water and only 1oz comes out and stops, its a 'leak' so needs to be continuously filled to 100oz until you can see how steady the leak is. its the rate at which it leaks.
itll make a lot more sense once you have the gauges and fire it up and see what happens. i was confused about the procedure when i got the stuff home too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Quick 200k Mile Motor &raquo;</TD></TR><TR><TD CLASS="quote">not a problem, just to give ya an idea this is basic procedure:

First, your compressor must be able to maintain 110psi (150psi max) tank pressure.
Connect the tester to the tank.
On the tester, adjust the regulator **** until the gauge on the tester reads exactly 100psi.

With the piston at TDC, when you connect the tester to spark plug hose, the cylinder gets pressurized and the % of pressure lost is presented on the gauge in psi (for example 98psi means 2% loss) because you put in 100psi in..
and 2psi was lost through: headgasket, valve seats, valve stem seals, piston rings, or tiny hole in piston etc..

An easy way to pin point the problem is by listening.
For example if you hear hiss coming from your coolant system, your headgasket is leaking. </TD></TR></TABLE>I see...REMEMBER, the only true reading is at 100 lbs imput otherwise it throws your % readings all off accordingly.
Say you have 100 lbs pressure in a non refillable bottle and you hook it to a cylinder with 10% leakdown. Eventually you will lose the 100lbs pressure in your bottle amd your 10% leak down will drop by the same portion until at zero lbs pressure, you show zero % leakdown. That's why holding a constant 100 lbs is important.
BTW, I still think that it is cool that you built your own tester

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">
BTW, I still think that it is cool that you built your own tester</TD></TR></TABLE>


Thanks Earl, I'm getting alot of good info on this. I still haven't tried it yet cause everyone I know who has an air compressor is out of town. But I'm going over to an uncle's house today to use his compressor. We'll see what happens.

Again, thanks guys for all your input.

 

oh BTW, if the air compressor reads 145 psi and i can control the amount going into the cylinder with the **** on the regulator...i can slowly increase pressure until it gets to 100psi and then cut it off there with the little pushing mechanisim that cuts airflow on the regulator and watch to see if the pressure gauge is going down right? would this work or would it not? this is the picture you guys gave me...well, the picture that i had in my mind after reading all the inputs.

 

http://store.summitracing.com/...00010
http://store.summitracing.com/...08015

If yours wont work.

 

cool thanks. but i'm guessing that if i buy another regulator i can make it work just like those ones. we'll see. i love building my own stuff

 

i dont see what the 2nd regulator is for if you already have one on your compressor plus the tank gauge?