brake booster faulty

[the head]

Just had lower hose split on me. I thought something was up about a week earlier when I would first start the engine, the brake pedal was stiff so all of the vacuum was gone. Taped for now and Durametric removed the code.

[the head]

Well I also did the repair with rubber hose and it seals just fine. However, I'm still getting the fault code along with a P1914 for a brake pressure sensor. I can hear the vacuum pump running when I step on the brake pedal. I have to drive about 10 seconds before it turns off. I'll try removing the pump and blowing it out, but I was just curious if anyone else had this much of an issue after the hose was fixed.

[Loren]

Well I also did the repair with rubber hose and it seals just fine. However, I'm still getting the fault code along with a P1914 for a brake pressure sensor. I can hear the vacuum pump running when I step on the brake pedal. I have to drive about 10 seconds before it turns off. I'll try removing the pump and blowing it out, but I was just curious if anyone else had this much of an issue after the hose was fixed.

P1914 Brake Booster Pressure Sensor – Signal Implausible/ No Signal

Possible cause of fault:

- Open circuit in sensor wire

- Connector removed from brake booster pressure sensor

- Disconnection point KE2, pin 5 disconnected

- Brake booster pressure sensor faulty

- DME control module faulty

[the head]

Had a second split line at the y-connector below the vacuum pump. It was hard to see but once I started removing things to look I finally saw it. So two split lines at once. No warning messages this morning on the way in to work - yay! But in the process of locating the second split line I also found a broken tee fitting for the turbo vent lines at the rear of the intake.

[Faceman]

Can someone tell me how to remove this hose.. Its the 7L5-611-931 G also known as 955-355-579-51

I cant figure out how to disconnect it at the hose just before it enters the fire wall.. There is a fatter plastic piece with a rubber washer about 1/8 inch from bottom where it connects..

Thanks!!

[Faceman]

Nevermind.. All I needed were some channel locks and a steady tug/twist..

[T2_996420]

We also had the same issue going on with our 2004 Cayenne Turbo at about 195000 miles on the ticker - there were a number of vacuum leaks and the vacuum pump was also replaced and now it is working AOK.

[EB_1920]

I have the same issue on my 05 CTT (80K miles). See picture below (right side of the hose)

I just ordered the vacuum hose, but it's a special order item, so it will take 5-7 days to arrive.

Two questions...

1) Is it okay to drive the car until the part arrives? I used some duct tape on the hose for now until the part arrives.

2) When I start the car with the plastic cover off, I can hear the brake booster squeal (or at least, I think it's the brake booster). Is that normal? Or is it just squealing because the vacuum line is split?

[wvicary]

Yes and Yes. Just be aware of the increased pedal effort.

[EB_1920]

Yes and Yes. Just be aware of the increased pedal effort.

Thanks wvicary!

[rharrison]

This has been a great post. Thanks to all who shared their experience. I used the 1/2" hose. I disconnected the connection to the booster to reset the light. This had to be done while running. All is now well.

[duo1]

Wow, simple fix. Renntech has saved me $$$ again.

My hose was split at the bottom near the expansion joiner and for now, duct tape fixed the job.

Started engine & fault code cleared when I backed the car out of the shed.

Thanks again guys !!

[stevepeck1]

I see a lot of references to the "lower hose." Mine (2005 CTT) is cracked as in the Duo1 and EB_1920 pics above. It's not what I'd call a "lower" hose as it is at the top of the engine bay. The rest below the car is fine. The dealer by parts disgram wants to sell me part 13 which appears to run under the car but the picture doesn't show this one-way valve... I think it's the wrong part and before i wait a week and drop $120... I thought I'd ask the guys who know! Thanks!

[mja305]

Had Exactly the same issue, cant believe this little piece of plastic 130 bucks. Crazy I tell ya

[royxaxa]

I had the same problem before

I ended up using a regular coolant hose and 2 clamps.

the OE one is not only expensive but also harder to replace.

[hahnmgh63]

$93.28 from Sonnen

[ohboy]

Same thing happened to me a month ago and the vacuum leak was the hose under the torque mount. I epoxied the crack and worked well. 05 cayenne turbo.

[cayenne444]

I had the same problem for the third time in 2 year for my CTT 05 (94000km),

In the first time I changed the brake booster (955 355 923 01) and vacuum line

Second time also vacuum line but different one

Third time I receive my CTT 05 today also vacuum line but different one

[Molitoth]

Hey all!

I recently got this error and have been doing some research.

Symptoms:

*Brake Booster Faulty code

*Brake Booster Master Cylinder? can be heard refilling with Air every time the brake is applied.

The most common tube that cracks is not the problem in my case; although I've taken a proactive approach to that problem and stuffed the OEM tube within a rubber tube so that I won't have to worry about it cracking in the future.

I've checked around the other tubes and cannot find any cracks, although I did follow a tube to back behind the engine and found that it had completely busted off at the T-connector.

Attached are some pictures showing where the T-connector is and the busted off tubing. I used a T-connector I had on hand in rigging the pieces back together hoping it would fix the problem but apparently it has not. When attempting to put the new T-Connector back in, the tube on the left completely broke off (brittle piece of crap) so I had to use other tubes and hose clamps to reduce it back down to size until I could order a new part.

My local Porsche mechanic states that any tubes in the vacuum line need to be extremely air tight and they use a sealer on the T-connectors as well as anything else.

So I was wondering if you could help me with.....

*A schematic showing the tubing I am dealing with

*I need to replace the part (hose) in the pic I have labeled with a "???" What is this???

*Any advice?

I know the dealer is going to want to charge me near $1000 to fix this dang issue which I think I could easily fix myself and Renntech.

Arrow pointing to Aluminum/Rubber hose that connects to T-Connector. Circled section is showing broken T-Connector.

A further away shot showing where I am playing...

Edited June 1, 2012 by Molitoth

[Molitoth]

Loren (echo.... echo.... echo....)

are you out there my friend? :jump:

[Loren]

A schematic of that does not exist.

Is that the line that goes to the front brakes?

[wvicary]

I'm not sure what that hose is used for. Is it under engine vacuum or a distribution pipe for the secondary air injection? Where do the pipes terminate?

Most parts have a part number printed on them so look around carefully for it.

[jagman1]

I think it's PCV. I noticed it broken when I did my coolant pipes and had the intake manifold off. I just took the old broken T out and put a new one in using the same lines.

I've noticed the same T broken on many pictures from coolant pipe replacements DIY's.

[Molitoth]

Thanks for the reply's guys! I haven't had time to dive back under the hood the past week, but as soon as I do I will try and find out more information.

[jsrbrown]

I just had this same issue. A liberal application of JB Weld and presto.... no more faulty brake booster light! This is a great site.