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View Full Version : Boost leak test - bloody throttle seals



Limeyboy
07-14-2007, 08:18 PM
After sorting the 5500 rpm "whoosh" screwups (flapping cold air scoop), re-tuning and doing a few runs, im still only doing 250 est WHP (DLL graphing, yeah not perfect, but im pretty anal on the input variables). Im down to zero knock at all loads/RPMS, but something is still up.

Time to put the new FG boost leak tester to good use :) Stripped out the intake components, fitted the leak tester and a (hand!!) pump. Got cracking and one good 'right arm workout 'later (no funny comments lads :P ), im up at 12 PSI. Well, I can hear the air pissing out. Took me a moment tnarrow it down - and yep, it is the throttle body seals that seem to be plaguing a few of us lately. No wonder my car is not going over 250!!!(The stock seals are rated to 7psi from factory (according to WORKS website) before they start to leak. According to my leak tester, my throttle body seals start pissing air (throttle closed) at 1 PSI. Its not too fast, but if I open the throttle, the pressure drops REAL fast. Like a BIG leak. Ah well, cant win em all ;)

Im going to get the seals fixed and re-run the test. From what I can hear so far, thats my only leak to just under 13 PSI. Who knows whats going to show up when I get the pressure up to the top.


heres what I did, in case anyone else who wants to do this test, does not know:

- Unbolt the three bolds holding in the air box.
- Unclip the wiring to the MAF (the wire to the left, kinda underneath the air filter box, above intake piping)
- Unclip the jubilee clip holding the air box to the intake piping (left of airbox)
- Gently lift airbox up and wiggle with a bit of pressure to remove from intake piping. Set to one side, trying not to get any crap inside it from the ground
- undo two jubilee clips holding rubber pipe between right side LICP (intercooler exit pipe) and UICP. Remove hose (not a strictly necassary step, but makes it easier for you)
- unclip jubilee clip connecting BOV to intake piping. Do not remove BOV from UCIP !!! Remove BOV from intake piping.
- Unclip jubilee clip on tubo to intake piping. Wiggle loose from turbo and then remove the vacuum line from the far side of intake piping and remove the small BCS pipe from underside of intake piping.
- Remove intake piping
- connect boost leak tester to turbo inlet and screw down with jubilee clip
- Reconnect rubber hose between exit LICP and UICP and clamp down with jubilee clips
- Connect compressed air source to boost leak tester. I used an 80PSI rated hand pump. If you dont want to grow biceps like Arnie, then I would recommend a compressor for this.
- Begin pumping till you hit 10PSI on the gauge. Stop pumping, see if the boost drops and listen for hisses. Find out where any hisses are and try to rectify (remember to return the pressure system to relative atmosphere before un-clipping anything!)
- If no hisses, then keep pumping to 15 PSI. Rinse and repeat. No hisses? Go to 24 PSI.
- If you reach 24 PSI and it holds, congrats, your system is perfect! If not, find your leaks n fix em.

When putting it all back together, dont forget to put the airbox back in with the lid on. On more than one occasion, I have put the airbox back in with no lid on, only to find I gotta take it all out again as the clips (that hold the lid on) are stuck pointing straight down.

hope this helps a few of you.

Full Function
08-01-2007, 02:39 PM
You can come by and use out boost leak tester unless you like the hand work-out, but I'm sure you can find better means to work those muscles.. (ahahah sorry I had to)

Jerry

Limeyboy
08-01-2007, 02:57 PM
LOL Jerry! And tnx for the offer!

Fa-Q
08-01-2007, 03:41 PM
maybe these will help:

http://www.worksevo.com/store/product_info.php?cPath=21&products_id=415

Limeyboy
08-02-2007, 01:50 PM
Or here... im told these fit

http://machv.com/throtbodseal.html

MarkSAE
08-02-2007, 02:18 PM
Or here... im told these fit

http://machv.com/throtbodseal.html


They must fit since Mach V sells those on their evo page... hehe..

http://www.machevo.com/thbose.html

I've replaced the TB shaft seals on my DSMs using the Mach V seals. They work good! And you don't need any kind of press to install them either.

chrisw
08-02-2007, 02:19 PM
Or here... im told these fit

http://machv.com/throtbodseal.html


I have these installed, but I know (from the individual who machines the throttle bodies for Works) that the works seals are stronger and rated for a higher PSI than the set that MachV sells.

Limeyboy
08-02-2007, 05:02 PM
Thanks Chrisw, I figured the same myself and tried to order from Works.. Works site was actually not letting me check out ( some internal server error) so I called Olly and got them that way. Should be with me tomorrow.

Matz
08-02-2007, 09:49 PM
Do you guys recommend changing those seals, even though one may not actually have a leak yet?

Limeyboy
08-03-2007, 09:16 AM
Stock is rated to 7psi, we regularly go over that. Its a weak component in the chain which will for sure one day fail. Preventative maintenance is always better than 'fix it when it breaks' maintenance.

BOOSTX2
08-03-2007, 12:15 PM
I'm curious is the system supposed to hold 25 psi with the t-body closed?
It seems to me it would not.(correct me if I'm wrong here)
In normal operation when you are boosting 21 psi the t-body blade is open.
as soon as you let off the T-body blade closes recirc valve opens no pressure
at the t-body blade.
But in doing the boost leak test one pressurises the system to 21+psi expecting
the t-body to hold pressure while checking the couplers w/soapy water solution.
It seems like this TEST would damage the seals at the shaft byÂ* prolonging
the amount of time the system is pressurized.
Does the evo t-body even seal airtight? I know a lot of T-bodys that don't.
I also need to do a BL test but I want to test piping and couplers only so I am
fabbing up a plug to plug off the t-body elbow thus not thrashing my poor t-body
seals..
Simon this is what I was telling you about I will make an Extra T-body elbow plug
for your BL test kit.
(your t-body seals will love you for this..) 8)

earlyapex aka jack ass
08-04-2007, 07:09 PM
Not sure if this was posted but here is a how-to change the seals:

http://forums.evolutionm.net/showthread.php?t=220264

missred
08-04-2007, 07:22 PM
Great info guys!

steevo8
08-04-2007, 07:59 PM
Anyone know if anyone besides works sells upgraded seals?

jbfoco
08-04-2007, 08:09 PM
http://machevo.com/thbose.html

steevo8
08-04-2007, 08:23 PM
good looking out homie

XVeloX
08-05-2007, 06:00 PM
IMHO the MachV ones are more or less junk. THey really aren't built to handle much boost, as they were designed for DSM's. Trust me, WORKS actually put some time into their seals for once (no offense, but lots of the other parts/flashes fail etc.). I had a LONG talk with a few of the employees a while back to get something like this in motion. I would spend the extra $8 bucks or so and get the WORKS seals.

Just make sure when you are replacing the stock ones, you dont score your throttle body and press the new ones in FULLY...



I'm curious is the system supposed to hold 25 psi with the t-body closed?
It seems to me it would not.(correct me if I'm wrong here)
In normal operation when you are boosting 21 psi the t-body blade is open.
as soon as you let off the T-body blade closes recirc valve opens no pressure
at the t-body blade.
But in doing the boost leak test one pressurises the system to 21+psi expecting
the t-body to hold pressure while checking the couplers w/soapy water solution.
It seems like this TEST would damage the seals at the shaft by prolonging
the amount of time the system is pressurized.
Does the evo t-body even seal airtight? I know a lot of T-bodys that don't.
I also need to do a BL test but I want to test piping and couplers only so I am
fabbing up a plug to plug off the t-body elbow thus not thrashing my poor t-body
seals..
Simon this is what I was telling you about I will make an Extra T-body elbow plug
for your BL test kit.
(your t-body seals will love you for this..) 8)


Well when you are boosting 21 psi lets say, i.e. your bosot gauge reads 21 psi, you *should* be measuring that pressure at the manifold, and no matter if the butterfly valve is opened or closed, it is still seeing 21 psi whether you are driving the car or are leak testing. The whole system is pressurized when you are boosting...

steevo8
08-06-2007, 07:12 AM
considering that works isnt the one actually manufacturing their seals they sell, what they did was put some time into sourcing someone who make quality seals.

XVeloX
08-06-2007, 07:57 AM
^ yup, fine with me. As long as they work i don't mind who makes em :)

BOOSTX2
08-06-2007, 10:14 AM
IMHO the MachV ones are more or less junk. THey really aren't built to handle much boost, as they were designed for DSM's. Trust me, WORKS actually put some time into their seals for once (no offense, but lots of the other parts/flashes fail etc.). I had a LONG talk with a few of the employees a while back to get something like this in motion. I would spend the extra $8 bucks or so and get the WORKS seals.

Just make sure when you are replacing the stock ones, you dont score your throttle body and press the new ones in FULLY...



I'm curious is the system supposed to hold 25 psi with the t-body closed?
It seems to me it would not.(correct me if I'm wrong here)
In normal operation when you are boosting 21 psi the t-body blade is open.
as soon as you let off the T-body blade closes recirc valve opens no pressure
at the t-body blade.
But in doing the boost leak test one pressurises the system to 21+psi expecting
the t-body to hold pressure while checking the couplers w/soapy water solution.
It seems like this TEST would damage the seals at the shaft by prolonging
the amount of time the system is pressurized.
Does the evo t-body even seal airtight? I know a lot of T-bodys that don't.
I also need to do a BL test but I want to test piping and couplers only so I am
fabbing up a plug to plug off the t-body elbow thus not thrashing my poor t-body
seals..
Simon this is what I was telling you about I will make an Extra T-body elbow plug
for your BL test kit.
(your t-body seals will love you for this..) 8)


Well when you are boosting 21 psi lets say, i.e. your bosot gauge reads 21 psi, you *should* be measuring that pressure at the manifold, and no matter if the butterfly valve is opened or closed, it is still seeing 21 psi whether you are driving the car or are leak testing. The whole system is pressurized when you are boosting...

I see what your saying here so when you do the test and pressurize the system
you are actually pressurizing the system from turbo inlet to the intake valve?
or past if valve is open?
Sorry for dumb Question
I thought the pressure would escape through the motor.
Do you pressurize and disconnect air supply? or do you regulate to desired PSI
and keep the air supply connected?
Thanks for the info BTW..

BOOSTX2
08-06-2007, 10:21 AM
Are other parts req. other than the t-body shaft seals?T-body gasket? Or do you
reuse the old T-body gasket?

chrisw
08-06-2007, 10:37 AM
the T-body gaskets are cheap. I never reuse gaskets if possible.

earlyapex aka jack ass
08-06-2007, 10:44 AM
It is a good idea to pressurize the whole system as i've seen leaks from the throttle body, injector rings, intake manifold gasket, vac lines off the intake manifold, etc.

Hook up the pressure tester to the turbo compressor housing and test in increments of 5psi, usually if it's leaking, you will find it by 15psi or so. It's also a good idea to open the TB plate while testing as this will be a true test of the system as you don't make boost driving the car with the TB plate closed. ;)

bricel24
08-06-2007, 11:10 AM
hmmm... now i think i have the same problem. im gonna order the Works seals and see how it goes.

Limeyboy
08-06-2007, 02:35 PM
Just a follow up - i took two hours on Saturday to change the seals for the works ones. Oliver sent me down the seals and a new gasket, so I got to work.

First thing in the write up from WORKS and on EvoM is "remove the strut tower brace"

I didn't really follow this step as I felt it un-necessary. If you remove the battery and the LICP and use the correct tools, the brace is not in the way :) No way im going to try to crack them bolts if i dont need to.

I would rate this job a 2 or 3 out of 10 on the difficulty scale, and I can definitely feel an improvement in the car. Old seals were leaking from 1psi with throttle closed or open. Leak was at a guesstimate 1psi/sec at close throttle, and about 2 or 3 PSI @ WOT.

P.S. for those that cant find it, manual calls for 14fl/lbs +/- 2 on the 4 throttle body bolts.

P.P.S you may find it easier to unclip the rear coolant hose from the throttle body once you have disconnected the body from the manifold. Rotate 90o or so. Just be aware coolant will leak if you hold it too low.

P.P.P.S : The WORKS writeup that came with the seals said when removing the TPS from the TB, you should mark the screws. Im personally more for doing what is set out in the EvoM write up - using a sharpie to mark the exact position of the TPS relative to the TB by marking across the TB to the TPS. Made it easy as pie for me to put back together.

BOOSTX2
08-06-2007, 02:59 PM
Thanks for all the info.. I'm going to change the seals as well..

Limeyboy
08-06-2007, 03:02 PM
Good luck Garry! Drop me a line if you need any help.

earlyapex aka jack ass
08-06-2007, 03:06 PM
Leak was at a guesstimate 1psi/sec at close throttle, and about 2 or 3 PSI @ WOT.




Damn that's a serious leak!

BOOSTX2
08-06-2007, 03:09 PM
Good luck Garry! Drop me a line if you need any help.

Thank you Simon all keep that in mind..

Limeyboy
08-06-2007, 03:45 PM
Damn that's a serious leak!


Indeed. When I pulled the rings out the rubber was mostly gone, just the metal ring itself with some hardened rubber stuck round the edges. No wonder it leaked like a nypho's undercarriage.

bricel24
08-06-2007, 03:54 PM
wow good info Simon! im gonna order the works seals and try to attempt installing them...

XVeloX
08-06-2007, 05:28 PM
haha sounds all too familiar. Mine held a whopping 3 psi.

I have played with my throttle body enough times now that it only takes about 30 min for start to finish to get it off. The writeup on EvoM is pretty good, just have shop towels ready underneath coolant lines, you will spill some.

if anyone has questions there are a few of us who have done these, feel free to ask...

Limeyboy
08-06-2007, 05:33 PM
Another tip I just remembered - when putting the TB back onto the intake manifold, its a good idea to tighten and torque the bolts in a diametrically opposite pattern. This lump of metal does get hot, last thing you want or need is a warped TB peeing air out..

steevo8
08-06-2007, 06:39 PM
hey limeyboy and xvelox, how many miles are on your car?

Limeyboy
08-06-2007, 07:04 PM
33k on an 03

DnB_design
08-07-2007, 02:51 PM
THANKS for the info, i think i am having the same problem,last week i started only hitting 12 PSI, so i check my hoses, and nothing....and have been going crazy not knowing what is going on...

Limeyboy
08-07-2007, 03:18 PM
hmm.. hitting a lower PSI may not indicate this problem. My seals were blowing, but I still hit just a bit lower regular PSI on the boost gauge (turbo just spins faster to compensate). Do a full leak test to be sure before carrying out this work! It may benefit you to reset the ECU, just to see if its in limp mode or something. Unplug the negative terminal of the battery for 15 minutes.

PANGES
08-07-2007, 06:14 PM
Neat.

earlyapex aka jack ass
08-07-2007, 07:20 PM
THANKS for the info, i think i am having the same problem,last week i started only hitting 12 PSI, so i check my hoses, and nothing....and have been going crazy not knowing what is going on...


Boost solenoid failed, boost control hose is off the compressor housing, hole in the line, or air is flowing around the pill. That is wastegate pressure.

Limeyboy
08-07-2007, 10:26 PM
Bryans probly right. He posted up about some other car doing WG pressure on the GST dyno. Now he mentions it, makes perfect sense. Thats not to say your TB seals aint leaking too ;) fix the fault, then do the leak test :)

XVeloX
08-08-2007, 07:25 AM
the seals started going out at ~50k miles. Seems about the time most people's are, not to say that i havent seen 05's blow the seals with less than 25k... But those are evom'ers, who knows what crazy stuff they do :P