Turbo vacuum fix?

Hi there! I have a question on how the vacuum chamber works, and if i can fix my problem the way i think. So, the previous ovner broke the nipple from the vacuum chamber that goes to the solenoid. the hose and the nipple has been blocked off. My question is, can i directly connect the vacuum pump hose to the hose that goes to the solenoid? I have attached a picture to explain what my situasjon is. Hope someone can help me :slight_smile:

You can but you will lose the function of whatever the solenoid controls whenever you are on boost.

Why not drill, use a pipe tap into the chamber so you can install threaded brass nipple to attach the solenoid hose to?


Oh, I haven’t thought of doing it that way. That sounds like a much better way to fix my problem, thanks!

I don’t quite comprehend what you have there but if it is just a nipplebthat has broken off, just replace it as mustangman said. I used a plastic fitting once to replace a broken one once. Just drill, tap, or screw the new one in. Available at Napa or others.

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I forgot to mention I have a underboost code that I’m trying to troubleshoot. I will try fit a new nipple and see how it goes :))

That vacuum line becomes a boost pressure line when the turbo comes on. The leak allows boost pressure to bleed off. So likely your underboost code will be fixed when the line is fixed.

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Use a very thin wall piece of steel/copper tubing as “insert” for broke nipple. The tube will reinforce the old broke plastic nipple. Uh, you have to have old plastic nipple to make it work.

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I hope so! Thank you for al your info :)) At the moment my turbo pressure is 4.35psi at 4000rpm. I have ordered a new nipple and hose, i guess it will turn up in about a week

Thats the problem, the previous ovner just filled the holde where the nipple used to be with epoxy or some other kind of glue… But i have now ordered a new nipple :))

I’m assuming you looked at the cost of a new vacuum chamber? They’re generally quite inexpensive. That is the appropriate fix.

How would you know? The OP never told us anything but Mazda Turbo. No year, model, or engine.

Why so touchy? Hence the reason I used the term “generally”. Is there a reason you feel the need to challenge my post? It wasn’t directed at you.

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Not touchy, the question stands on its own. It wasn’t rhetorical.
Any challange is in your mind only. Sorry if I touched a nerve.

Yes, that was my first thought. But the vacuum chamber is connected to my air filter box housing assembly. To keep it stock i would have to get a new top for the filter box. I have a mazda 6 from 2007, so its hard to come by, and would set me back $100. Buying a new nipple and hose cost me $4

I don’t understand. Could you explain what you mean? I’ve no turbo experience, but thinking the vacuum chamber/vacuum pump is needed on turbo engine designs to provide a source of reliable vacuum for other vacuum controlled devices in the car (like the brake booster).I wouldn’t expect the vacuum chamber would be involved with the boost pressure. Except perhaps it supplies vacuum to operate a vacuum actuator for a boost-related function. Is that what you mean?

Another somewhat related puzzle I don’t understand either, why do diesel engines require this same arrangement?

Under anything but wide open throttle, the manifold pressure is below atmospheric… i. e. a vacuum. Turbochargers pump air at a positive pressure into the engine to make more power on demand when the throttle plate is open… so the manifold pressure becomes higher than atmospheric… i.e. no vacuum, pressure.

Light throttle, manifold has vacuum, heavy throttle, higher pressue.

A brake booster has enough capacity, for 2 full stops with the engine off (no vacuum), by standard.

As far as what the device the OP posted does, no clue, as we didn’t even know the car until a couple of posts ago.

Diesels have no vacuum because they don’t throttle air, they throttle fuel. Diesels run very lean at idle and the richer it gets, the more power it makes until it rolls coal. More air allows more power so turbos are almost standard on diesels these days.

Both engine types need to limit max boost so there are limiters that bypass exhaust gas when the pressure gets to a preset limit.


Hi again! I would just like to share that the fix that you recommended worked fantastic! Before the fix i got 4.35psi at 4000rpm, now i get 23.2psi at 4000rpm.


Isn’t it great when the repair you try actually works?


Yes, it is a great feeling. And it is not something you can purchase, only obtained by diligent (& sometimes just lucky) diy’er efforts.

It’s one of the best feelings!