# Cracked Hose leading into brake booster



## gtisound (Sep 15, 2004)

I noticed that my car idled roughly this morning. Then I checked under the hood and noticed a large crack in a hard black pipe that leads to the brake booster. I assume this pipe is a vacuum pipe, but could someone verify the part# 1J0 612 041 BS. 

Hopefully it's not one of those expensive vw hoses, but something is telling me it's not a $10 part from the dealership. OTOH, I can't complain too much because my car has been fairly reliable.


----------



## crayolawolf (Feb 15, 2010)

yep, that's the same # i got off of mine this weekend -- which was also cracked at either end. i also had rough idling and occasional loss of brake boost at low speeds. that original part # has been superseded by vw part # 1J0612041ES. ecstuning sells it (ES#308112) for about $55 (!). it's so expensive because the hose is not sold in pieces, so that part # actually includes 2 bits of hose with the valve in the middle. i also have not found any aftermarket better quality hose specifically meant to replace it (i don't really want to put more crappy expensive vw hose in there, just to have it crack again later). would love to know if anyone knows of a silicone aftermarket replacement for that part #. mine has temporarily been replaced by $3 of thick tubing from lowe's and a couple of hose clamps. :laugh:


----------



## UmbroVR6 (May 23, 2000)

bump!


----------



## Rod Ratio (Jun 6, 2012)

tjjoiner said:


> Sorry to bring this thread back from the dead, but aside from trying to stay OEM, is there any reason why this hose can't be replaced with rubber fuel line, vacuum line, etc.?


Soft hose will collapse under vacuum, and cause you to lose your brakes on the highway at triple digit speed. Ask me how I know.


----------



## TurboZen (Oct 15, 2000)

^^^ good to know.

I got the vw oem replacement for about $43. My engine is AWD model and the original hose appears to have been heated up and just jammed onto the master cylinders nipple. I just used around a 3 inch piece of hose that I used to join the new part to the MC nipple. I also had to use a hose clamp to keep it from popping out at the intake.

Eventually I will doing the "Removing SAI, N249, PCV, EVAP" mod and will use most of this new hose as it's rigid and wont deflate under high vacuum.


----------



## Rod Ratio (Jun 6, 2012)

Yea, it was a harrowing experience to say the least. I was ripping down the highway after I replumbed everything, traffic stopped dead ahead of me, I went to hit the brakes, and NOTHING.

I had to dive onto the shoulder, and shoot past a bunch of stopped traffic like Johnny Tran. Felt like a total a$$hat


----------



## BoostedGLS0218 (Dec 10, 2011)

Rod Ratio said:


> Yea, it was a harrowing experience to say the least. I was ripping down the highway after I replumbed everything, traffic stopped dead ahead of me, I went to hit the brakes, and NOTHING.
> 
> I had to dive onto the shoulder, and shoot past a bunch of stopped traffic like Johnny Tran. Felt like a total a$$hat


Wow! 
That sounds terrible!
I've actually re plumbed the whole brake booster system. I ran a piece of silicon hose from the side port on the IM to the check valve towards the firewall that was there..
All that makes me want to pull that out and find a source of some hard vacuum line. Any ideas? Autozone, napa, pepboys or whoever only seems to have crappy types of vacuum hose.


----------



## groggory (Apr 21, 2003)

McMaster Carr carries many types of tubing that will do the job.

You want a tube that's rated for ~30 in Hg vacuum and can take engine bay temperatures.

As such, my two recommendations would be:

High-Pressure/Vacuum Polyethylene Tubing
Part # 50375K84 ($.032/ft) assuming you can keep it under 150F : 

or

Extreme-Temperature Tubing Made with PTFE and Teflon® PTFE
Part # 55515K531 ($16.57/ft) if you have one hot ass mother engine bay

PS...those part numbers are for 1/2" tubing. I can't remember what size tubing the brake booster uses, so I just guessed


----------



## Shamrock (Aug 7, 2004)

I used 1/2" vac line. pretty much like this hose from the Delete DIY. Thats been over 2 years now. I've been fine, I didn't think there'd be an issue with vac. line?


----------



## Rod Ratio (Jun 6, 2012)

BoostedGLS0218 said:


> Wow!
> That sounds terrible!
> I've actually re plumbed the whole brake booster system. I ran a piece of silicon hose from the side port on the IM to the check valve towards the firewall that was there..
> All that makes me want to pull that out and find a source of some hard vacuum line. Any ideas? Autozone, napa, pepboys or whoever only seems to have crappy types of vacuum hose.


Yea, go hard line for sure. I've heard of guys using Pex tubing, or just go with Groggorys suggestion. Probably the best route:beer:


----------



## tjjoiner (Jul 25, 2012)

I figured it had something to do with the vacuum collapsing the tubing.



groggory said:


> PS...those part numbers are for 1/2" tubing. I can't remember what size tubing the brake booster uses, so I just guessed


Close. It's about 3/8" ID.

But yeah, those two lines suggested above appear to be the best bang for the buck.

I wonder how well nylon tubing would work (http://www.mcmaster.com/#standard-vacuum-rated-nylon-tubing/=lczy3k). Good temp. range and can handle the vacuum, but might be too hard to get on without applying a bit of heat.



> Vacuum-Rated Nylon Tubing
> - Flexible
> - Hard (Rockwell R112)
> - Temperature Range: -40° to 225° F
> ...


----------



## formerly silveratljetta (Feb 6, 2007)

tjjoiner said:


> Sorry to bring this thread back from the dead, but aside from trying to stay OEM, is there any reason why this hose can't be replaced with rubber fuel line, vacuum line, etc.?


I am replacing mine with 1/2" reinforced rubber fuel line. No way that stuff is going to collapse under vacuum. The only thing I cannot decide is how many check valves to use?

I only use 1 vac port off the manifold even though the car uses 2 vac ports in the stock configuration.


----------



## groggory (Apr 21, 2003)

formerly silveratljetta said:


> I am replacing mine with 1/2" reinforced rubber fuel line. No way that stuff is going to collapse under vacuum. The only thing I cannot decide is how many check valves to use?
> 
> I only use 1 vac port off the manifold even though the car uses 2 vac ports in the stock configuration.


I think the stock configuration also uses the suction jet pump on the second nipple to create vac while under boost


----------



## halchka99 (Apr 18, 2002)

formerly silveratljetta said:


> I am replacing mine with 1/2" reinforced rubber fuel line. No way that stuff is going to collapse under vacuum. .



this is what i have done...


----------



## Twopnt016v (Jul 5, 2009)

groggory said:


> I think the stock configuration also uses the suction jet pump on the second nipple to create vac while under boost


It helps increase the vacuum supply. That same valve is used on NA cars. That valve is also used to send fuel from one side of the fuel tank to the other side on some cars with "saddle bag" tanks.


----------



## halchka99 (Apr 18, 2002)

do you guys think it would be an issue to run a vac manifold between intake mani and check valve?


----------



## groggory (Apr 21, 2003)

halchka99 said:


> do you guys think it would be an issue to run a vac manifold between intake mani and check valve?


I personally wouldn't

I think the brake booster should get as clean a vac input as possible


----------



## Twopnt016v (Jul 5, 2009)

Gregg don't you have that snazzy 42dd vac manifold on your car? That mounts right off the intake manifold in between the intake manifold and the first check valve?...


----------



## tjjoiner (Jul 25, 2012)

formerly silveratljetta said:


> I am replacing mine with 1/2" reinforced rubber fuel line. No way that stuff is going to collapse under vacuum.
> 
> 
> 
> ...


$1.29 a foot at O'Reilly, rated up to 24 in/Hg, -40 to 257 F. Looks like this is what I'll be doing, too.


----------



## groggory (Apr 21, 2003)

Twopnt016v said:


> Gregg don't you have that snazzy 42dd vac manifold on your car? That mounts right off the intake manifold in between the intake manifold and the first check valve?...


I do have the 42dd vac mani... But the brake booster isn't connected to it. Brake booster has a dedicated 3/8 port off the intake mani


----------



## 18T_BT (Sep 15, 2005)

I run one OEM check valve for many years now without issues so far, but I am not opposed to running two actually. I do keep a second as a spare in the car. 

I don't see why you couldn't plumb a vacuum reservoir before the check valve like halchka. It's not like it diminishes vacuum to the brake booster in any way. Once positive pressure is applied, the check valve closes. There aren't any maybe this, maybe that about it.


----------



## halchka99 (Apr 18, 2002)

what would running 2 check valves inline do? Wouldn't the first inline just shut pressure out and it would never get to the second valve?


----------



## groggory (Apr 21, 2003)

halchka99 said:


> what would running 2 check valves inline do? Wouldn't the first inline just shut pressure out and it would never get to the second valve?


Maybe it's a safety thing...

Intake Mani -> check valve -> vacuum res -> check valve -> brake booster

If either check valve fails open, your brakes will still work as normal.

I can see that method working well if you come from an aerospace background. lol. But our cars don't fly, so we won't go into triple redundancy.


----------



## 18T_BT (Sep 15, 2005)

halchka99 said:


> what would running 2 check valves inline do? Wouldn't the first inline just shut pressure out and it would never get to the second valve?


It's a safety net in case 1 fails is all. Usually, they don't fail. Hence why my spare is sitting in my car and not installed.


----------



## Rod Ratio (Jun 6, 2012)

So... Would the ideal situation be to install a vacuum reservoir between two check valves on the brake booster line?

I smell a 'vacuum system FAQ' coming from Groggory opcorn:


----------

