Pump is new, date code 2013, but it's good that I pulled it...

c

 

Looks as if you found a leak.

 

What sucks is that the bad hose disappears through the firewall, so replacement is likely not easy. Others have sleeved it with 1/2" hose, but I don't seem to have enough room to wrap anything around it. I used a zip tie to fasten it tightly to the barb fitting, then blobbed some white caulk over the injury. Kind of how Bones repaired the Horta on Star Trek. I was going to use permatex, but mine has gone old and separated, the silicone I've got is a 24hr cure and I need to drive in 3hrs, so caulk it is. I'll see what happens in a few hours.

cheers,
c

 

Does that line connect to the intake on the engine anywhere? Or just to the brake booster?

If it's the brake booster, silicone is probably fine.

What isn't good is using silicone sealer on any vacuum lines/fittings going to the intake. The outgassing from the silicone will end up travelling through the cylinder and poisoning the O2 sensors.

Just a heads up..

 

Good point, I didn't think of that. Good news is that I couldn't find my silicone that I wanted to use, so it's actually got latex caulk on it. Very kludgely, but I need the car in a few hours and I figure I'll be able to see if that's the only leak or not. Also, latex cures in about 10 mins. I can't believe the garbage hard lines Porsche uses on a $100,000 vehicle. This line punches through the firewall behind the glovebox. Anyone know where it leads or how bad it is to replace?

I'd really prefer to get a tubing bender and replace anything that fails over time with metal.

cheers,
c

 

That looks like a pretty typical split.

If it is the crossover hose that goes under the cowl to the brake booster, it is not that bad to replace. It does not go through the real firewall, just some kind of false second firewall for the cowl.

There are many people that have had good luck with tape and zip ties for these types of repairs for thousands of miles on their Cayennes, so I think you can make it work until you can do a better patch job. The leaks tend to be at the fittings, so it is not out of the realm of best practice to cut it and replace a section with a piece of hose that will last much longer than Porsche's crap plastic.

If you take a mighty vac to where the pump hooks into the system and run some vacuum, you will be able to tell if it will hold and/or if there are other leaks. Just do not pump it too hard or you could damage your brake booster itself which will be a major PITA.

 

My crap repair. I'm not proud.

c

 

I drove around the block and it didn't clear, but that didn't clear it last time either so I cleared it with the iCarScan. Last time it came back after a mile or two of driving, so I should know later this evening if it's fixed or not. I'll post here with an update.

cheers,
c

 

You could try shrink tubing as a patch....available at Home Depot electrical dept. in a variety of sizes. I would double up on it for added strength.

The Gen 1 Cayenne S through Turbo S sold for anywhere between $60 and and about $130K. Under the hood and chassis P used the same crappy plastic parts and connectors, regardless of the MSRP.

There is a reason why P enjoys the highest SUV profit margin in industry...$17K per unit is the most recent estimate. Its way overpriced for what it is but as long as it sells well there is no reason to change.

 

Made it 4mi before brake booster warning reappeared. %!^%**%!$^#@(!!!!!!!!!!!!!!

c

 

I'm thinking of buying a smoke machine, not one of the $800 redline ones. One of the $80 ebay ones:
http://www.ebay.com/itm/EVAP-Smoke-M...-/282339070632

They get pretty good reviews on Amazon. Anyone got any experience with these? Any gotchas? Seems like it would pay for itself pretty quickly in the plumber's nightmare Cayenne.

cheers,
c

 

****UPDATE**** PROBLEM SOLVED!!!!

My Brake Booster Failure! error was the result of the same split hose behind and below the vacuum pump that has been a problem for so many others. My original "fix" was clamping it onto the barb fitting with a couple of zip-ties then blobbing over the whole thing with household latex caulk. I cleared the error, it came back in a few miles on my first drive. Today, I pulled it apart again.

Hint #1: After removing the pump, also remove the pump bracket (2) 10mm head hex bolts. Gently move the bracket toward the engine since it has hard vacuum lines clipped to it and they don't come off easily. This gives much better access.

Hint #2: With the bracket out of the way it's MUCH easier to get your hands around the split line for cleaning (simple green) and maneuvering it.

I have some 5/8" NAPA heater hose (for Jimi Fix) that others have used with success, but it was taking a lot of force to try to slip it over the hose and I didn't want to make the problem worse. I went to O'Reily, AutoZone and NAPA looking for something more flexible to sleeve it with (silicone hose, or heat shrink, etc.). No luck at the first two, NAPA was super-helpful and let me come around back to inspect all the various hoses. Most were too stiff, and I picked one that I thought might be an improvement over the heater hose (wasn't sure). On my way winding through the aisles to get back to the register, I came across a special display (not by the other hoses) for "FLEXZILLA" hose. It's a flourescent green very flexible silicone hose. I bought a foot of the 5/8" ID (too big) as well as the 1/2" ID (just right). I got home and cut-off a 2" slice and worked it down onto the hard line.

Hint #3: with the vac pump bracket out of the way you can get one hand under the broken hard line to support it at the bend.

It slid over pretty easily by just taking turns pushing all around the perimeter while supporting the bend in the hard line with the other hand. Once I had it on pretty far (beyond the crack), I used a single edge razor blade to cut it just a little longer than the hard line that it's sleeving. This stuff cuts VERY easily, nothing like heater hose, more like surgical tubing. I then slipped the check valve into it, which seemed to have the correct amount of resistance and put the rest back together. I DID NOT clear the code this time, I just went for a drive around the block. The "Brake Booster Failure!" was there along with the loud beep when I started the car and also the yellow "Service Vehicle Now!" message that normally follows it. It cleared itself after about 1/2 mile of slow speed driving though the neighborhood. I now have NO ERRORS in the Cayenne. A first for me in this vehicle, also brakes feel a little stronger.

Hint #4: The hose that works great is NAPA #827-1136 (Flexzilla 1/2 x 250) it's bright green and only $1.69/ft

Hope this helps someone. Thanks all for the help.

cheers,
c

 

I intend to solve the root cause of the issue on my vehicle but if I cleared the fault via a Durametric cable (or similar) how long would it take for the fault to reappear? Would it occur immediately upon startup?

 

I cleared it a few times before actually fixing the problem. In each case, the error returned within 5mi or less (but not on startup). It appears that once fixed, it actually clears-itself in less time than it takes to trigger the error in the first place. Mine went away in less than 1/2 mile.

cheers,
c

 

OK thank you very much. I ordered an inexpensive code reader so I could clear the code and at least get the car inspected while I sort this out.