Quick Spark Plug & Brake Fluid Question
 

I am about to replace my spark plugs on my 951, but I in the workshop manual and Clark's Garage is saying to put oil on the threads. I've always been taught to use anti-sieze compound. What do you guys think? Which one is better or preferable and why?

I am also about to do a brake fluid flush and I am seeing clark's garage is saying to use DOT 4 only in all caps. The car manual says any DOT 3 or DOT 4 fluid will be fine. Now I'm confused. Again, which one do I use and why?

I'd just like to make sure of everything before I get to work on the vehicle. Thanks for everyone's help! :)

I never put oil on the treat for spark plugs, it might cause carbon built up on the treat, better to use anti- sieze.
As for brake fluid DOT # , the higher the number the higher the boiling point.
Racing brake fluid is DOT 5.

--------------------------------------------
Bud

87 930 Black
86 951 Black
86 944 N/A Red (part car)
87 944 S White
83 944 N/A Black
83 944 N/A White

I use anti sieze on my spark plugs, no problem

Dot 4 will have a higher boiling point fro brake fluid so thats what I use. Dot5 uses silicone which might not be compatible and might create problems. Here is what I found using google;
http://www.xs11.com/tips/maintenance/maint1.shtml

If silicone is introduced into an older brake system, the silicone will latch unto the sludge generated by gradual component deterioration and create a gelatin like goop which will attract more crud and eventually plug up metering orifices or cause pistons to stick. If you have already changed to DOT 5, don't compound your initial mistake and change back. Silicone is very tenacious stuff and you will never get it all out of your system. Just change the fluid regularly. For those who race using silicone fluid, I recommend that you crack the bleed screws before each racing session to insure that there is no water in the calipers.

I use anti seize. I bought it in a 1/2 pint size container that has a cap with a brush on it. this makes it easy to put on and since the container is large...I never loose it and can find it when I need it. I use it on the lug nuts too.

Vern

Anti-seize here as well.

Dont put dot3 in, dot 4 or something like the super blue racing fluid.

Regarding the Brake Fluid, I reccomend going with the ATE Super Blue. This is good because the blue color makes it very easy to tell when the system is fully flushed.

Vern

Awhile back, when playing with 914's, I learned a trick... anti-seize is a poor conductor, so is oil. However, we don't want our plugs becoming lodged in the head. So the trick was to use Milk of Magnesia. You can get a huge bottle of it at any drug store and it will last you forever. Something in it acts as an anti-seize agent and it has better electrical properties then anti-seize. I have used it for about 5 years on multiple cars with aluminum heads and have never had a problem. I even had "mint flavored"... that was all I could find. I take the bottle and pour it into the cap of the bottle, about half full, and then use a q-tip to wipe it on the threads of the plug. I would say I have done this for about a dozen plug changes on BMW's, Porsche's and Mercedes and it really does work. It is a lot cheaper then anti-seize, and a lot easier to clean up. It is also not that bad for the environment. :)
+1 on the Super Blue and then the Gold ATE... going back and forth makes it easy to see when you are done. DOT 5 is not good stuff for street or even ocassional DE cars. Yes, I have tried it and have gone back to the DOT4 for a few reasons... not the least of which is that it is much easier to source, cheaper and I really could never notice a difference. YMMV

OK, The manual says that Because DOT 4 is compadable with DOT 3 systems, But Nvere put DOT 3 in a Dot 4 system. Get it. I believe the Porsche Manual says to install plugs dry

Scott,

been playing with cars the past 20 years or so.

PLUGS: Oil on the threads (a light smear) and hand tight only ! (then a 1/4 turn)
Plugs get jammed in cos there over tightened, you only need to make a gas tight seal. You can use anti-sieze as well, with either I have had "NO" problems

Brake fluid, you can mix 3 & 4, though if your not sure what you have use DOT4
DONT USE DOT5, its silicone, you will have to completely drain your existing fluid and probably need to change all the seals as well.

You can use DOT 5.1 as thats not silicone, and yes you can mix all if you want.

TBH might be good to drian/flush system and refill with what ever DOT you want

I don't use anti size compound on my plugs ( to me it is one more thing to go wrong). The key is to never over tighten the plugs. Once the plugs are in a seated, a small nudge with the ratchet will be enough. I have never had a problem with this technique.

I don't use anti seize compound on my plugs ( to me it is one more thing to go wrong). The key is to never over tighten the plugs. Once the plugs are in a seated, a small nudge with the ratchet will be enough. I have never had a problem with this technique.

Thanks for all the information everyone! Very informative!