: few head gasket procedure questions



mountain14er
08-21-06, 02:57 PM
Hi all. I'm gathering parts and reading the procedure for replacing my head gasket. So far I have two quesitons regarding the procedure in the factory manual.

1. Is it really necessary to 'recover the AC system" or can I just unbolt the compressor from the engine and leave the in tact AC system connected to the car?

2. Dissabling the ABS: I'm guessing I can't just pull the ABS fuse and call it good. The manual describes undoing the electrical connections under the dash for the driver and passenger airbags but that seems excessive.

Thanks for the help.

Ranger
08-21-06, 06:40 PM
I have heard others say, and even post a pic of the compressor simply unmounted and the system left charged.

Are you talking about the ABS (Antilock Brake System) or the IRS (Inflatable Restraint System). If the latter, I would think the fuse alone would work. That's all I do.

zonie77
08-21-06, 06:51 PM
You don't have your car in your profile...add it so we know what it is.

If it's an N* you probabaly have to open the line to get the AC out of the way.

We were able to get the ABS out of the way without discoing any of the brake lines.

The airbag is easy to disconnect and a good safety measure. Even though the battery is disco'd I believe the airbag has a charged capacitor that could set it off.

Ranger
08-21-06, 07:55 PM
Zonie,
Don't quote me on this but I seem to recall the FSM eluding to (if not saying it) that the capacitor will discharge after a few seconds. I recall calulating that it would take me longer to get to the air bag mounting screws after pulling the fuse. I would guess a :15 minute wait would be more than adequate to insure it is asleep.

zonie77
08-21-06, 08:25 PM
Ranger, you are correct, some say 2 minutes is enough. They are easy to access so I unplugged just to be safe. You know the old better safe than sorry line.:)

Ranger
08-21-06, 08:33 PM
Yup, but I've always been somewhat of a risk taker. I even run with scissors. :rolleyes:

mountain14er
08-21-06, 11:20 PM
Sorry for the brain fart on the ABS; I meant IRS (the kind that helps, not the one that hurts every April 15th.).

It's a 99 Deville so a 4.6 Northstar. After re-reading the procedure, unplugging the units is easy enough and probably worth doing.

Also, I guess I'll just have someone recover the coolant and put more back in when I'm done.

Ranger
08-21-06, 11:34 PM
"Recover the coolant"?

I assume you mean refrigerant. Yes.

zonie77
08-22-06, 12:54 AM
I have all the equipment so it's no big deal to open the AC. I'm not sure if you could get it out of the way. It was easier to take it off than fight with it, but if you don't have gauges or pump you might try to keep it closed.

Take a look and see if it's possible to move it.

The AC oil absorbs moisture. The dessicant in the accumulator absorbs moisture. The evacuation procedure is to get the moisture out before you refill it. If you took it apart and immediately resealed it you wouldn't have to evacuate it. As you reassemble the car you would open it for the few minutes to move the compressor and lines into position and reassemble it again. Just don't leave them open long and don't open them on a rainy day.

And don't be reckless like Ranger and run with scissors! My Mom won't let me have the pointy ones.

brown1904
08-22-06, 08:38 AM
Hello I have just bought a 1996 seville off ebay. Some has taken heads off engine. Where can I find procedures on putting engine back together.? Would you share the info you have? I did not do enough homework before buying car,otherwise I would have left alone. Any help would be appr.

mountain14er
08-22-06, 09:56 AM
brown 1904- I would suggest starting another post with the same quesiton but if Alldata and the factory service manuals aren't identical, they're close so start there.

mountain14er
08-22-06, 10:00 AM
OK, I'll probably just follow the FSM entirely but that's good to know about the refrigerant purge as an anti-moisture move only.

Another question I had was regarding the drive axles. It seems like the pictures I've seen on this site of removing the powertrain assembly show the front springs/struts, etc. attached to the powetrain. The manual calls for disconnecting the ball joints and drive axles. Am I correct in assuming these are two different techniques and which one do you prefer (1999 Deville)? Thanks.

brown1904
08-22-06, 03:03 PM
Sorry I did not mean to impose on your post. New to Forums. Thanks

Ranger
08-22-06, 05:13 PM
Brown,
Since you are new to forums, that is known as highjacking a thread. It's best to start your own.

BTW :welcome:

zonie77
08-22-06, 10:34 PM
Brown & Mountain. I did a write up on doing the head gaskets. It's in the tech tips section. N* Head gasket repair I think.

You do not have to pull the axles if you are only doing the heads.

mountain14er
08-23-06, 11:46 AM
Thanks Zonie77, that tech article has been very helpful. I'm just trying to reconcile all the little differences in the FSM.