RomRaider

I dont mean to beat the dead horse, but I built a boost leak tester and figured I would post my parts list and a diagram. All of these parts can be purchased at Home Depot and Autozone. The parts list has color coded letter labels to match the diagram.

Parts List: https://spreadsheets.google.com/spreadsheet/pub?hl=en_US&hl=en_US&key=0Aqradj0S_qvndFZhMHk0RkN5Qm92SE9vZG9DNHFTTEE&output=html

Basic Instructions:

1) cut the 2 foot of 3/8" vaccume line into 2 separate pieces
2) put a "Watts 3/8 in. x 1/4 in. Brass Compression x MIP Adapter with Insert" at each end of both hoses
3) drill 2 x 3/8" holes in the 2" pvc plug and then screw each of the hoses into the 2" pvc plug
4) insert the 2" pvc plug into the silicone coupling and tighten it
5) unscrew the stem cover from the tire pressure gauge to reveal a 1/8" threaded fitting
6) screw the 1/4" to 1/8" adapter fitting onto the 1/8" threaded fitting on the tire gauge
7) screw the tire gauge onto the other end of one of the hoses
screw the 1/4" male compressor npt fitting into one of the sides of the 1/4" on/off ball valve
9) screw the other end of the ball valve onto the remaining end of one of the air hoses

Note: be sure to use thread tape on everything

Diagram:






Performing the Boost Leak Test:

1) Disconnect and plug the bottom hose on the purge control solenoid
2) Remove the aftermaf and connect the tester to the turbo inlet
4) Make sure the tester's on/off ball valve is in the off position
3) Connect your compressor to the tester's 1/4" npt fitting and set the compressor's regulator to a little over what you want to fill the system with
4) Turn the the tester's on/off ball valve to the on position and fill to your desired psi and then turn it off
5) Listen for hissing and use soapy water to help locate leaks
6) Fix leaks
7) Drink Beer

Let me know if you have any questions. I hope this helps.

Ryan

Testing instructions added to first post.

Thanks for this diy! Hows it working out for you?

It worked great. I didnt really have any boost leaks, just a couple of slightly leaky nipples on my inlet which i fixed with small hose clamps.

Aside from those inlet nipples, what are usually sources of boost leaks that go unnoticed ?

Various places including intercooler piping, bpv/bov lines and hoses, intercooler to turbo, ic to tb, etc... FMIC piping is pretty prone to leaks...

You should probably post what lines need to be plugged so we dont have people blowing oil seals...
It'd also be good to tell people what to look for pressure wise in a well sealed system

I mostly just meant this to be a DIY for the tester itself, but when I get back in town Monday I will try to elaborate a little on the process.

That's great , , nice DIY. Thanks.

Thanks, lets wait for the update. Eager to get this going as well. I got an old perrin maf afta hose I can use. I just need a plug and the hoses .

I added some testing instructions to the top.

02rexwi: was the purge valve the line you were referring to?

I simply filled the system the first time I heard a leak and a humming/buzzing noise comming from the purge control valve. I disconnected the bottom hose (see picture below) and plugged it and the system drained much slower and the humming/buzzing noise stopped.

How much beer is recommended?

It was suggested pressure not to exceed 25psi. The lower the better as long as you find the leak?
Whats in danger of popping out?

You want to make sure that you are capping off the crankcase breather lines if you are pressurizing off of the turbo inlet.
It depends on the car we are talking about, but on the 02-05' WRX and 04-07' STI you have to cap off the 2 crankcase breather lines, and the purge control line.
I find that a set of drill bits works the best because they are all different sizes, but make sure you secure them with zip ties or hose clamps.

Depending on the size of the air compressor used I like to see at least 20 psi. on the laptop (I mount it in the engine bay).
If you're using a small compressor you wont be able to get the volume of air to pressurize the entire system to 20 psi. especially if you have a FMIC.
I like to pressurize the system to 1-3 psi. over the amount of boost you plan to run, that way you know that the there wont be hoses popping off when driving, and no leaks will develop from higher boost levels.

A small boost leak can be found with a soapy bottle of water, but most leaks that will cause a tuning problem will be too large to be found with a spray bottle.

You should also know that if you cant get the system to pressurize at all or only a little the engine may be in the valve overlap position, meaning that both the intake and exhaust valves are open a little. If this happens you can either turn the engine over by hand, or bump the starter.

If you're having problems finding a leak on a TMIC setup (often from the Y pipe) you can take the TMIC off and pressurize the engine directly into the throttle body. You will have to make a plug to cap off the TMIC on one end and pressurize it from the other end.

Also, as a rule of thumb I always take off the oil cap just to be safe, because if something is overlooked for some reason and pressure does go into the crankcase it can be vented before causing any damage to oil seals.


That's about all I have to add to the subject ATM. Sorry for the long post

"Enough to fill the system"

Sry to bumb up the thread again, but I'm not really sure, what exactly to cap off for doing a save boost leak test (must go to 30 psi). It looks like, that not everbody do it the same way.
I attached two pictures. Do I have to cap off all marked lines + take off the oil cap? Can someone confirm that please?

And when I want to pressurize the engine directly into the throttle body, do I have to cap off only the Nr 4?

Lines...
1. boost solenoid return (why cap this off?)
2. hose vacuum to purge valve
3. hose vacuum crankcase breather lines to the left and right head (PCV)
4. hose (pressurize or vacuum) to purge valve (why cap this off?)
5./6. hose vacuum crankcase breathe middle (PCV)