[LKLusza]

Hi Folks,
After dealing with SBCs for 40 years, this is my first foray into Pontiacs and their maintenance and I have a question about the Pontiac cooling system. Background: 1970 GTO, Std 400, Auto, PS, PB, and AC.

Problem: I have an oil leak from either the front of the oil pan or the crank seal - can't tell which.

Well, in for a penny, in for a pound, so I ordered the Felpro 45166 timing cover gasket set. So, the manual says to drain the radiator (which I'll remove to provide more space in which to work anyway), as well as the block (something I never had to do with a SBC).

Is draining the block absolutely necessary or can I skip that part? I just changed the oil and don't want to risk any contamination when I pull the water pump or timing cover. Any other pointers about timing cover removal would be greatly appreciated. Thanks.

[rohrt]

Not sure if all block have this, but my 455 had 2 small plugs at the bottom of the block on each side. Pretty easy to get to for me and drains the block almost 100%.

[steve25]

Those small 1/8" pipe drain plugs above the oil pan lip on each side of the motor can be a real pain to get out, and many times when you do get them out the hole is pretty well blocked .

Just Take the lower rad hose off at the rad then with a catch can under then remove Then remove the rad cap.

When it gets to just bare dribble jack up the ass end of the car until that's just a dribble, at that point put the car back down and as long as your work area is somewhat level your then golden for yanking the timing cover off!

[AG]

All blocks have the drain plugs, sometimes it is very difficult to get them out but it's the best way. If you can't get them out, completely drain the radiator, jack up the front of the car 4 inches and you won't have any coolant coming out of the front timing cover holes.

[johnta1]

X2 on what Steve and AG said.

Raising the back to drain the fluid then after that, raise the front to work on the timing cover area.
(need to raise front anyway to get to some of the bolts)

[LKLusza]

Thanks for the swift replies.

Looking at the bottom of the engine, I identified the two drain plugs - not going to mess with them if I don't have to.

I'm used to the whole "jack up the back to drain / lift the front up to work" deal. It's what worked on Chevys and seems to be the ticket here too. Just wanted to be sure. Thanks again.

[STEELCITYFIREBIRD]

If your in there, I'd have a timing chain set on hand....just in case.
Also a good opportunity to check and set the water pump to separator plate clearance.
In for a pound and a half.

[steve25]

Sorry, my version was more for when you need to yank the heads also.

[sdbob]

Drain the oil. If any coolant goes into pan it's easier to wash out.If changing chain I usually shove a rag into pan under chain so anything doesnt fall into pan,like keys. I have had it happen.

[Stuart]

If you do decide to remove the drain plugs in the block, replace them with those little brass petcocks that are used in radiators. They're the same pipe thread, and make draining coolant a lot easier next time.

[AG]

Originally Posted by Stuart

If you do decide to remove the drain plugs in the block, replace them with those little brass petcocks that are used in radiators. They're the same pipe thread, and make draining coolant a lot easier next time.

X2, do it with every block I build.

[72projectbird]

When you remove the timing cover, it'll drain itself whether you like it or not. lol

[ZeGermanHam]

Originally Posted by Stuart

If you do decide to remove the drain plugs in the block, replace them with those little brass petcocks that are used in radiators. They're the same pipe thread, and make draining coolant a lot easier next time.

I like this idea! Adding to my to-do list...

[Goatracer1]

You don't have to remove the timing cover to change the crank seal. Just remove center crank bolt and slip off the balancer. It should slide off easily. If not a large screw driver should pop it off. You don't need a puller like a Chevy. Try that and see if your leak is gone. If not you can always change the pan gasket later.

[krisr]

If you don't have petcocks on the side (like every build should get) then just use a 2 stroke oil syringe with some hose to suck the coolant level below the opening and you're done.

[LKLusza]

I really like the idea of replacing the block plugs with petcocks - brilliant idea! The car is an older restoration and not an untouched original. Being a bit of a Garage Queen with the PO, the engines only got about 5k on a complete overhaul (have dated receipts). So I suppose there ought not to be too much trouble going that route.

I use a set of Race Ramps 12" cribs for maintenance work and had thought to "dip" the front end after draining - sort of like a actor taking a bow at the end of a performance. Then put it back up and go to work. But the petcock idea makes a lot of sense too.

I'll be removing the rad and shroud for working space, so after the gasket set gets here on Tuesday, I'll get to work. And yes, if it's only the seal, I'll try replacing it on the car - no sense looking for unnecessary trouble.

Thanks, Guys, for all the great ideas and advice - I appreciate it very much.

[Schurkey]

Originally Posted by Stuart

If you do decide to remove the drain plugs in the block, replace them with those little brass petcocks that are used in radiators. They're the same pipe thread, and make draining coolant a lot easier next time.

Sure about that?

Pretty sure the Firebird P-455 I did for my Father-in-Law had 1/4" pipe thread in the radiator, and 1/8" pipe thread in the block.

[Sirrotica]

Be aware that the bottom of the block usually has all the rust sediment from the whole cooling system, even if you install the petcocks, the sediment can, and does plug off that portion of the block.

One year I drained the block on my 67 GTO/clone stock car (picture in signature) before winter by removing the pipe plugs. The sediment dammed up the hole on one side stopping the rest of the water from draining out of that side of the block, unbeknownst to me. The following spring I'm getting it ready to fire up and when I crawl under it to replace the pipe plugs there's a soft plug laying on the starter that pushed out during the winter. I was extremely lucky it didn't crack the block.......

The theory of draining the block through those 2 openings is great, but because they are so small, and there is a lot of sediment that accumulates right in that area, it doesn't always work out as engineered....

[Ben M.]

Originally Posted by Sirrotica

The theory of draining the block through those 2 openings is great, but because they are so small, and there is a lot of sediment that accumulates right in that area, it doesn't always work out as engineered....

The Pontiac engineers had them from the factory as petcocks in the '50s when the blocks were brand new, and it was expected the owner would drain their coolant once a year through those petcocks per the service manual (and it also included comments about "not using salt as antifreeze").

The amount of sediment it takes to plug those off accumulates over many years. I've installed petcocks on numerous engines of mine over the years and they still run free on the oldest engine I still have (from 2007). Every single factory plug I've removed has had a ton of debris in them though, it does require cleaning if you do that.

[firechicken]

Petcocks don't work on filled blocks like mine lol.
My aluminum rad doesn't even have a drain so I just use a siphon hose through the rad cap opening to the bottom of the rad. Achieves the same thing as pulling the lower hose but without the mess.