oh crap, cleaned the caliper guiding bolts with brake cleaner
 

I changed the rear brake pads and rotors. Unfortunately I cleaned the caliper guiding bolts (#6 in the diagram) using CRC brake parts cleaner which is also a degreaser. Should I grease them up or replace them with new ones? I don't want to risk the calipers seizing up due to lack of lubrication. If it's safe to grease them up, what grease to use?

Thanks for any pointers!

X5 4.4 2005, 98k miles.

Yes, those pins should be greased. The brake cleaner won't harm them, but installing them dry will. ATE makes a good grease for those pins. But any caliper grease will do.

Most autozones/advance autos sell "brake caliper grease" in those little $1.50 packets you buy at the checkout counter, yes they need to be lubed.

No need to replace the pins but yes unbolt and regrease, and reinstall.

I always recommend some blue Loctite or at least making sure torqueing properly the caliper mounting bolt #3, the one that bolts to the spindle. Last thing you want is your caliper coming loose on the road (seen it happen to VW guys many times)

Do not grease those pins. They are designed to be installed dry. See the BMW instructions if you doubt that.

The risk is that any lubricant can cause the guide sleeves to swell. That is what causes calipers to stick.

Also, make sure the protective caps are in place. They keep the pins clean and dry.

Also, I agree that the pins should be properly torqued. However, IIRC the torque spec is dry, so using anything on the threads would most likely result in over tightening, unless you adjust the torque spec down, and then you would just be guessing anyway. Better to do it properly.

Edit: two links for those who want them. Seems we had this discussion previously

http://www.xoutpost.com/bmw-sav-foru...-pad-wear.html

http://www.xoutpost.com/bmw-sav-foru...ront-pads.html

:doh: Well I feel like a dope. So my apologies to the OP for giving you the wrong information on the pins.

JCL: Errrr, ummm... Hmmmm.... DARNIT! haha. I;ve been greasing those pins since I got the 4.4, I haven't touched the 4.8 yet. Funny thing is, back in 2004 when the maintenance plan was just about to run out on the 4.4, I brought it in for front and rear brakes. After getting it back and because of the way my brain functions, I took the front calipers off so I could clean them. Well, I saw, the pins were lubed. So after cleaning everything and putting things back together I went on with my life. After a while, she needed brakes again. Went to the dealer to ask what grease they use for the guide pins, guy says, "Molybdenum" So looking, I found the grease I talked to the OP about. Well... I learned something today!

Should have looked for the info on the internet instead of dealer. Stupid doesn't fix dumb.

Thanks for the info JCL. Now the next time I take the calipers off, its going to be difficult wrap my mind around the fact NOT TO GREASE the pins, haha.

Whoops, sorry for the bad info OP! I always was under the impression the guide pins needed lubricant (what are those small packets of grease at the stores used for anyway Jeff?)

And as far as Loctite goes I was talking about the actual 16mm bolts that hold the caliper assembly on the wheel carrier at the back, those I have seen come loose from undertorqueing in my VW days :)

Well, Mazda Miata caliper pins need grease, so it is apparently a special case for each application. I used Permatex Ultra Disc Brake Caliper Lube that comes in a plastic bottle and has a brush applicator. The grease is green.

Here are a couple of other links related to not lubricating BMW guide pins (not X5,) one has a graphic reference to the TIS:

To Lube or not to Lube Brake Guide Pin - Bimmerfest - BMW Forums

What fluids (only) should be used in a typical E39 brake job? - Page 3 - Bimmerfest - BMW Forums

The high temperature "grease" is for the ears of the pads where they contact the callipers, and for any external sliding surfaces. Not for the sealed pins running in guide sleeves

Pins that are external and exposed to the elements have metal to metal contact, and should be greased.

I've done numerous brake jobs on new BMWs, and all the pins I took out were dry from the factory.

They were dry when I took them out. They were dirty so I cleaned them up with brake cleaner. Later read that they should just be cleaned with a cloth and not a de-greaser since they have special coating of very light lubrication from the factory. Using brake cleaner removes this coating. Is this special coating a myth? I'm I ok with my current dry installation?

Yes, the TIS mention "not to lube" the guide pins. However, the brake fluid has to be changed every 2 years. At this interval, it's best to take the wheels off, and thoroughly inspect the condition of the brakes. Your life and your passenger life's depend on it. At this time is a good habit to also check the guide pins. They are protected by the dust caps (one of the reasons not to use lube, but there are also design differences between guide pins that need lubrication - like other car makes). If one of the guide pins looks dirtier than the others, maybe the dust cap is failing. Just buy a new one from the dealership, or better, change them all. The others won't be far behind.

Another aspect to check, and this is very important, because in my e39 it induced a shimmy I chased for eons. The dust boots of the piston calipers wear in time, and start not sealing anymore. This will lead to the protruding piston to start to rust and pitting.
So you can overhaul the calipers by replacing the boots (ATE has kits, sold by vendors like ECS Tuning, Pelican, Autohaus, probably dealerships) AND if the piston doesn't look too bad, you can polish them. If they are pitted badly you need to change them. Again, some get lucky and can get a replacement piston, if not a new brake caliper is in order. Here is a DIY on how to overhaul and service the brake calipers. And below is how a piston caliper is rusted up because of failing caliper rubber boots (this condition WILL induce shimmy, and you will have a hard time chasing it). Side-by-side comparison between new & old:

http://i825.photobucket.com/albums/z...ps42970125.jpg