[E93Seattle (Racerbruce)]

I've begun replacing my vacuum lines with high-temp silicone lines.

There's a vacuum line that connects to the brake vacuum line that terminates at the brake booster near the master cylinder and ABS, etc.

I went to Realoem (with my VIN selected) and it does not show this vacuum line that I have on my car.

The first pic is the Realoem diagram and item #9 is the line I'm asking about.

The second pic has a yellow arrow to the line that is not shown on the Realoem diagram.

2013 335is N54 E93 retractable hardtop.

The line I'm researching T's off of the main brake vacuum line and I don't know where it goes.

You will see 2 new red lines I've installed in the underhood photo; one is the 1/4 in line to the BOV and the other red line is the one in question.

Perhaps someone can help me ID that smaller red vacuum line that I just installed - where does it go? What does it do?

Efthreeoh, Strada, Gnome? Others?

[StradaRedlands]

I don't know, but it does match the car nicely!!!

[eastsidaz]

Originally Posted by E93Seattle (Racerbruce)

I've begun replacing my vacuum lines with high-temp silicone lines.

There's a vacuum line that connects to the brake vacuum line that terminates at the brake booster near the master cylinder and ABS, etc.

I went to Realoem (with my VIN selected) and it does not show this vacuum line that I have on my car.

The first pic is the Realoem diagram and item #9 is the line I'm asking about.

The second pic has a yellow arrow to the line that is not shown on the Realoem diagram.

2013 335is N54 E93 retractable hardtop.

The line I'm researching T's off of the main brake vacuum line and I don't know where it goes.

You will see 2 new red lines I've installed in the underhood photo; one is the 1/4 in line to the BOV and the other red line is the one in question.

Perhaps someone can help me ID that smaller red vacuum line that I just installed - where does it go? What does it do?

Efthreeoh, Strada, Gnome? Others?

Attachment 3199096

Attachment 3199097

Afaik it's the vac for the rear exhaust flap. Usually most have done the golf tee mod at the rear end though.

[E93Seattle (Racerbruce)]

Originally Posted by GovernUrMental

Afaik it's the vac for the rear exhaust flap. Usually most have done the golf tee mod at the rear end though.

thank you govern,
purchased her in dec of last yr and found the thread on this site re the exhaust flap; there are multiple options from this thread on how to plug the line to make the exhaust flap open 24/7; i chose the option of purchasing a small ball bearing from ace hardware that is a tight interference fit in the flexible vacuum tube where it connects to the metal nipple on the exhaust flap valve and inserting the ball bearing in the flexible vacuum tube and pushing the tube back on the metal nipple of the valve; now the exhaust flap valve is open 24/7.

it's interesting that realoem's depiction of this is not accurate; as stated in my initial post, i have bookmarked the realoem site and am using my vin #.

it was playing in my head that this was the line to the exhaust flap but did not know - thank you.

[eastsidaz]

Originally Posted by E93Seattle (Racerbruce)

thank you govern,
purchased her in dec of last yr and found the thread on this site re the exhaust flap; there are multiple options from this thread on how to plug the line to make the exhaust flap open 24/7; i chose the option of purchasing a small ball bearing from ace hardware that is a tight interference fit in the flexible vacuum tube where it connects to the metal nipple on the exhaust flap valve and inserting the ball bearing in the flexible vacuum tube and pushing the tube back on the metal nipple of the valve; now the exhaust flap valve is open 24/7.

it's interesting that realoem's depiction of this is not accurate; as stated in my initial post, i have bookmarked the realoem site and am using my vin #.

it was playing in my head that this was the line to the exhaust flap but did not know - thank you.

Ball bearing thats crazy! Search up Golf tee mod. I say it was probably my first mod

Edit: added link https://www.youtube.com/watch?v=GXksIV71auM

[E93Seattle (Racerbruce)]

Originally Posted by GovernUrMental

Ball bearing thats crazy! Search up Golf tee mod. I say it was probably my first mod

i know!
didn't want something hanging out of a vacuum line and wanted to land the vacuum tube back on the metal nipple....i think i purchased 3 that were slightly different od's and used the one that created a tight interference fit.

love an ace hardware where you can find entirely random stuff like this.

[lowrydr310]

The realOEM description is accurate, it's just splitting up different systems/components. The first RealOEM photo even shows the T fitting on the brake booster line (right next to #9) though doesn't have anything conencted.

Under the "Vacuum control, exhaust flap" diagram in the Exhaust section it shows the vacuum line that connects to that T fitting on the brake booster vacuum line, though there are no current part numbers or no specific BMW part listed.


I'm doing the same thing - which tubing did you order? Everyone seems to recommend the Verocious 3.5mm platinum cured silicone. I've heard mixed things that 3.5mm is OK and that 4mm is OK but not sure what to get.

I usually don't care about underhood aesthetics but that red tubing and the red BOV on the red car looks pretty cool.

[E93Seattle (Racerbruce)]

Originally Posted by lowrydr310

The realOEM description is accurate, it's just splitting up different systems/components. The first RealOEM photo even shows the T fitting on the brake booster line (right next to #9) though doesn't have anything conencted.

Under the "Vacuum control, exhaust flap" diagram in the Exhaust section it shows the vacuum line that connects to that T fitting on the brake booster vacuum line, though there are no current part numbers or no specific BMW part listed.


I'm doing the same thing - which tubing did you order? Everyone seems to recommend the Verocious 3.5mm platinum cured silicone. I've heard mixed things that 3.5mm is OK and that 4mm is OK but not sure what to get.

I usually don't care about underhood aesthetics but that red tubing and the red BOV on the red car looks pretty cool.

thank you lowry,
you're correct - i went back and enlarged the realoem page and could see the t fitting "grayed out" where it would be placed depending on the model, etc.

https://www.verociousmotorsports.com...ld-by-the-foot

when you read the description of this high quality vacuum line on their website, it becomes clear that not all vacuum lines are created equal and this product appears to be far superior to the others; i just began replacing the easy-to-reach lines and the 3.5 id mm hose is clearly a good choice and although the od of the of the hose is larger (due to increased wall thickness) the lines have still fit in the oem clips where they are held and directed in their paths; you can see that the od is pinched just a bit in the oem clips due to the larger od but the pinch is not restricting the id portion of the hose materially.

i suggest that bmw's oem vacuum line sizing of 3.5 mm (as stated in the realoem pages) is the proper sizing; based upon the three lines i've replaced, i suggest that a 4 mm id hose may not provide enough interference fit and it did not require anything but (sorry, tmi) using a toothpick with a bit of saliva on it and rubbed inside the new hose prior to slipping onto the oem fittings.

i'm sure you're already aware of this - the majority of all of the oem fittings are plastic or nylon and are heat cycled and extremely brittle; i read a ton of pages on our site about replacing the vacuum lines and they overly stress the need to take an exacto knife or a single edge razor blade and cut the oem vacuum line vertically along the length of the oem fitting it lands on - (careful not to cut too deep as to then create an in-line leak source on the oem fitting); i did this on the three lines i've replaced to-date and the oem vacuum line came off relatively easily.

there are some lines, like the small line on the turbos that are almost impossible to reach; take a look at this ingenious idea to address these:

https://www.e90post.com/forums/showthread.php?t=1440745