rrmorris67

My all original 85K mile TPI 305 is leaking coolant like a sieve on the passenger side b/t the manifold and the head. I am in the middle of tearing it down to replace the gaskets and re-seal the manifold. The Haynes and Chilton manuals' instructions are incredibly generalistic. I am desperately seeking all the tips and tricks that I can from those who have done this repair before so that I can make absolutely sure this sucker doesn't leak on me again.

For instance, I've had a guy tell me to use a thin coat of RTV on both sides of the gaskets as well as on the china walls of the block. Sound right? The manuals don't mention this. Also that I need to let the RTV sit until it is set up well (not tacky). Also I have been advised to coat all the manifold bolt threads with permatex #2. The manuals don't mention that either. Sound right? Any other tips or warnings about doing this job? THANK YOU!

Rice Killer87

Yes
Never heard of that,I do it while its tacky.
Sure
[/QUOTE]
good luck!

slayer6x6

Def. use RTV on the acutal block. Ive never heard of letting the sealant get tacky though.

pearlpurple

I agree with RiceKiller87

I would also keep the following in mind since you indicate that the coolant is leaking significantly.

1) Have you checked your oil lately for coolant??? If you haven't already and don't know what to look for: look for a milk shake texture or bubbles on the dipstick. If you find that you have coolant in the oil do not run the engine again.
2) Make sure once you have had the manifold off that you change the oil and filter first before firing it back up. This is even if no coolant is found in your oil.

splinter_cell

My moms car also has the same leak as you. Her car runs sloppy and likes to stutter alot. Are those symptoms caused by the leak?

IROC-T

When using RTV to form a gasket you should let it start to set so that it does not all squish out when you tighten the bolts. When using RTV on a gasket you don't want to let it set ,as you have a gasket already you are just using it as a sealing agent. That gasket leak is a common problem ,and what I do is once a year after I change the coolant I add one half (only)container of Alumiseal as a preventive. I only had it leak one time since '88 doing this and have talked to afew machanics that also use this solution.

ws6transam

Last I checked, you dont want to use RTV on the gasket. What you REALLY want is the Permatex ultra-copper gasket dressing, which comes in a spray can. Spray both sides of the gasket, let it sit for a while to dry, then place the gasket in place. The stuff will be copper colored and quite tacky.

After placing your gaskets, get your Permatex ultra-copper RTV, and squeeze a bead onto the front of the block from one gasket edge to an9other, paying particular attention to the corners where the cylinder head meets the block. Squeeze in a bead about a quarter inch high, then drop your intake manifold on top and tighten the bolts to 25-30 ft.lbs in the GM prescribed sequence: middle bolts first, working ******ds towards the front and back.

IROC-T

I feel the same way ,and don't ,BUT alot of people do and that is the best way if you are going to use it for that reason. You are absolutly right and I should have mentioned that,but his post said that he was told to use it.

ws6transam

No problem! In fact as the truth ought to be told, I did use a tiny amount of RTV on my intake gaskets just the other day because I was lazy and didnt have any of the ultra-copper gasket dressing spray handy! I simply spread a thin layer in a quarter inch wide circle around each of the four coolant passages on the bottom side of the intake gasket.