K-A

Recently got my car serviced and they notified that the drive belt tensioner is slightly leaking. They said it's no biggie as of now but that my Fidelity Platinum coverage will cover it, so obviously I'll be doing it. He also said there's a fairly cheap drive belt ($60 or so) that I can pay for and have them install while it's out, just to preemptively save from the potential future labor.

Anyone come across this in a 991.1?

Also, how often do you guys change your brake fluid? I haven't confirmed in the maintenance book yet, but he said it's supposed to be done every 2 years. Which means mine would be due. Is this something people are generally on top of on their cars? Hadn't heard it come up for something apparently so commonly done.

Fortunately when my PDK was replaced (the old one worked great but made some clattering sounds and shudders for a very brief period when immediately driving exclusively uphill after cold starts.... imagine how ecstatic I was when I found a dealer that could actually reproduce such a nuanced issue) my transmission fluid was changed, so I'm good there.

CSK 911 C4S

Changing brake fluid at the 2 year mark has been common for as long as I can remember.

Attached is the maintenance list for the 991.1. It might be easier to digest than reading the manual.

Class5Kayaker

Drive belt is only like $20 for OEM Supplier part. Tensioner should be easy to swap out, it's just getting in there that takes a bit. I posted a DIY on changing the belt here which will give you an idea of all that's involved: https://rennlist.com/forums/991/1043...ement-diy.html

Tensioner is #7 in the diagram below:

AdamSanta85

That's the belt

https://www.fcpeuro.com/products/por...911-crp-6k1767

K-A

Thanks. Guess it won't hurt to do the tensioner since it's covered.

TwinTurbo420

Porsche says change brake fluid every 2 years regardless of mileage.
I think that is an oversimplification since some very dry climates probably can easily go longer & some humid climates may need it done more frequently.
You can buy an inexpensive brake fluid tester that will tell you the % water in your brake fluid.

Such as:

OEM Brake Fluid Tester model: 25269
I bought from Amazon for ~ $23.00
"With the OEMTOOLS Brake Fluid Tester , you can easily, quickly and precisely check the water content of all 8 types of polyglycol-based brake fluids DOT 3, DOT 4, DOT 5. 1, Adecco DOT 3, Pennzoil, Preston, Motor craft and Toyota DOT 3."

So, if you test it yourself @ 2 years & have <1% water, do you really need to change it now?
Or if @ 1 year, you have between 3-4%, maybe you should change it?

I cannot find any source that discusses a reason other than moisture content for changing brake fluid.
For example a garage queen, driven only a few hundred miles/yr., still needs an oil & filter change with synthetic oil at 1 year.

K-A

Thank you. Problem is I don’t have access to something to use to get under the car and drain it, so would have to trust the shop. Is there a certain moisture level that serves as a bar for when to change the fluid?

Class5Kayaker

You test at the resevoir which is located in the frunk area. No need for a lift or draining anything.

Here's a chart explaining how percentages of moisture affect various types of brake fluid:


Here's a link to a decent explanation of how this all "works."

https://www.epicbleedsolutions.com/r...t-brake-fluid/

TwinTurbo420

Yes you check % water content right @ the brake fluid reservoir.
If you are not tracking the car, I'm guessing < 2% s/b OK. YMMV.
Dry climates probably do not need it changed every 2 years.
Do some Google searches.

3-Pedals

Does anyone know the torque values of the bolts mounting the tensioner? Do you need new bolts or can you reuse the old ones?

MingusDew

I used new ones just because the tensioner kit I bought came with them. The damper came with my belt service kit, the part description wasn’t too clear (no picture), so I also mistakenly purchased an unneeded extra damper, which I’m just saving for the future because these things seem to fail after a few years. Just buy the belt service kit and you’ll be good: https://www.fcpeuro.com/products/por...l-ina-6k1767kt This has all the belts, the tensioner with damper, the idler pulley, belt and bolts, plus FCP Euro has lifetime replacement, so you can use that to replace these parts for less $ (have to pay return shipping on old parts) the next time.

I had to use a low profile socket/wrench set. Not sure you can get a torque wrench to fit. Given the limited access, you probably won’t be over torquing them anyways.

The most challenging part was figuring out how to get the carriage bolt out. I ended up loosening three bolts (circled in blue) that attach the engine with the cross brace, and using a pry bar to push the engine and rear cross brace apart, hopefully this diagram makes sense:



This made it VERY easy to slide the carriage bolt out/in. People talk about tapping it out with a mallet, which works fine, but I could not figure out how to get it back in and align while taping it with a mallet. Used the above pry bar technique and it was super easy, just slid right back into place.

Hopefully this helps some, if you have more questions feel free to ask.