Hallman pro Leak

[my dreamt dsm]

I'm having problems with my hallman boost controller. As I was doing a boost leak the other day I couldn't get past 5psi and notice that my hallman is leaking through a little hole on the wastegate side. Also been having boost issues maybe caused by this.
What could cause that to happen and I'm sure it's not normal.
I'm likely going to black rtv it or get a new one. Are you guys having problems with that also.

 

[dsm03]

Same thing with mines. It was faulty.. then fell off..

Got a new one will try and let you know what happens, if it fixes my problem with the new MBC.

 

[my dreamt dsm]

I didn't notice it before. The problem just popped up. I might just rtv it for the heck of it. Although it says to leave it open. So we'll see.

 

[TSiAWD666]

Well the little hole is there to bleed wastegate pressure when you're off boost so the line doesn't stay pressurized and the wastegate open. Perhaps your ball inside (looks like a ball and spring mbc) isn't seating cleanly resulting in the boost leak past the ball and thus out the hole. I'd try opening it all up and cleaning it out.

Used to happen when I paid attention to MBC stuff years ago as I guess some form of gunk/carbon would build up around the ball enough to prevent it from seating cleanly. I'm pretty out of touch with MBC tech these days as I've had an electronic for quite some time.

 

[my dreamt dsm]

Well the little hole is there to bleed wastegate pressure when you're off boost so the line doesn't stay pressurized and the wastegate open. Perhaps your ball inside (looks like a ball and spring mbc) isn't seating cleanly resulting in the boost leak past the ball and thus out the hole. I'd try opening it all up and cleaning it out.

Used to happen when I paid attention to MBC stuff years ago as I guess some form of gunk/carbon would build up around the ball enough to prevent it from seating cleanly. I'm pretty out of touch with MBC tech these days as I've had an electronic for quite some time.

You know what I think you might be right. I'll open it up and check it out as I remember not seeing the ball so I guess it's internally fug or I got the hoses backwards.

 

[RavenX]

I've had a Hallman Pro MBC for years now and never had this issue. I do know about that little hole. I thought it was weird too but I've never had boost issues. Hope you fix it.

 

[my dreamt dsm]

I've had a Hallman Pro MBC for years now and never had this issue. I do know about that little hole. I thought it was weird too but I've never had boost issues. Hope you fix it.

Haven't touch it yet but I never had leaks issue there. Just popped up one day. When you do blt do you notice air coming out.

 

[blackhawkgsx]

I did a blt and noticed air coming from there so I disconnected my bc and ran the line from turbo to the wg and air came from the wg

 

[snowborder714]

It's a bleeder style boost controller. There is a small hole in it - this is normal. You should be disconnecting the boost source line and plugging it before you do the test.

 

[my dreamt dsm]

It's a bleeder style boost controller. There is a small hole in it - this is normal. You should be disconnecting the boost source line and plugging it before you do the test.

Thanks, but even though you by pass it for the BLT wouldn't it still cause problems during boost while driving. Cause with it hooked up it's causing me to lag right before the boost kicks in on my little healthy t25.

 

[snowborder714]

If it would, do you think people would be running them and they would be the most popular MBC?

How do you think the bleeder hole in the MBC is causing turbo lag?
How are your lines ran?
Are they as short as possible?
Are they tee'd into anything?
Where are you getting your boost source from?

 

[my dreamt dsm]

If it would, do you think people would be running them and they would be the most popular MBC?

How do you think the bleeder hole in the MBC is causing turbo lag? Before turbo fully boost you could feel air escape to the point where it's to much for the hole and then hit max psi and drops.
How are your lines ran? good question, I'lll have to recheck that.
Are they as short as possible? yes, pretty much.
Are they tee'd into anything? nope, Im running the 1g bov.
Where are you getting your boost source from? Compressor housing

I'll get back to you guys tomorrow!
Thanks for putting up with me Brian

 

[RavenX]

Yup I've had air leak through the hole when doing a BLT. I always thought it was supposed to be that way. Usually now I will just back out the knob on the boost controller so that its "closed" so I can do the test and it doesn't leak. Once am done I return it to where it was.

 

[biglady112]

If you turn the controller in(turn the boost up) you will not get a leak from that bleeder hole until you reach a higher pressure level. It is normal to leak from that hole.

 

[Dert]

Generally when you do a blt you are supposed to unhook your mbc as they will always leak air out the bleeder hole


Sent from my iPhone using Tapatalk

 

[my dreamt dsm]

Generally when you do a blt you are supposed to unhook your mbc as they will always leak air out the bleeder hole


Sent from my iPhone using Tapatalk

Thanks I stupidly somehow forgot about that. But just a thought if it leaks when doing a BLT... wouldn't it leak during regular boosting?

 

[snowborder714]

It's not considered a leak if it was put there intentionally. If you want to undo what the company has done and plug it up, let me know how it works, as I don't think it will properly.

 

[UofACATS]

Personally I wouldn't call the Hallman Pro MBC a bleeder type MBC. It controls boost by internal spring pressure, adjusted by rotating the top cap. The small "bleeder" hole is not responsible for altering the signal sent to the wastegate, the actual MBC performs that function. A bleeder-type MBC (if I understand correctly) actually bleeds off the desired increase in boost. A bleeder type MBC is affected by weather changes and that's why a bleeder type MBC has been labeled a "spike machine," while the Hallman Pro has no such issue.

-A bleeder type valve could cause a very slight bit of lag since a small amount of boost is bled off.
-A spring type valve does not cause any lag because it prevents the wastegate from seeing boost until the adjustment level is achieved. With the way most wastegate actuators open before target boost is achieved, it could actually help spool up.


The small hole In the Hallman Pro is designed to relieve any "trapped" pressure which may remain in-between the wastegate actuator and the MBC. The pressure which may remain in this portion of the signal line is equivalent to the amount of boost over wastegate pressure your MBC is providing.

Example: A 10psi wastegate actuator with the MBC adjusted to open at 5psi equals 15psi of total boost pressure. Under WOT the signal line to the MBC is seeing 15psi, and the signal to the wastegate itself is seeing 10psi. When the throttle is let off, the signal to the MBC drops to vacuum obviously, but the signal in-between the MBC and the wastegate actuator still has 5psi trapped inside. There is no where for the pressure to go because on one side we have a 10psi wastegate actuator and on the other side we have a 5psi MBC setting.

This is where the hearsay starts: I've read that this remaining pressure can cause issues with the turbo re-spooling, but in theory I don't see why. My guess is that a wastegate opens well before its ultimate highest boost setting, but on the other hand a small amount of pressure which could accumulate in the short and small diameter line shouldn't have any discernible affect.

This bleeder hole is addressed in the MBC install instructions, but the specifics as to why are not.

You must be logged in to view this image or video.

To boost leak test with your Hallman Pro MBC installed: Adjust the MBC to a value over that which you will be using for your BLT. Example: If you BLT to 30psi, adjust the MBC to open at 31 or higher psi. You can do this by tightening the valve to its maximum value. It will not leak during the BLT because the small bleeder hole is on the barb which goes to the wastegate actuator.

 

[black97spyder]

I am having the same problem as the op right now. I have air constantly pushing out the little bleeder hole, whether I'm cruising under vaccum or under boost... The more I boost the more air that comes out of the little hole? I was told there should only be air leaving the hole when u let off the throttle after boosting? Any other insight on my problem??