[bdude273]

Hello

I'm trying to remove the cylinder heads on my Cadillac 472 and was wondering if anyone could post instructions on how to do it. I'm planning on getting a service manual but it would take a long time to ship because it would first need to go to Washington state then I would have to pick it up in a few weeks which I can't wait for.

Thanks!

 

[deVille33]

You have a big job ahead of you. First question: Engine to be disassembled in car?
Disconnect battery, Throttle linkages, electrical connections (engine wiring Harness) to AC and other electronic units on the intake manifold, Vacuum lines to manifold ports and carb, fuel lines and fuel vapor recovery lines. It maybe helpful to label the connectors so you can easily reconnect during reassembly. Another thing you can do would be to Take detailed pictures to help you with reassembly. You will have to remove the AC compressor. You should discharge the system first if it can't be moved out of the work area. Then remove the intake manifold. Do not remove the carb unless you plan to rebuild it, but ensure you keep it in the same position it normally sits. You can mess up the internal settings if you position it otherwise.
Hard part will be the exhaust system. If you can get an impact tool on the bolts nuts you may be able to remove the manifolds without breaking tem off. If you break them, you will have an added expense to remove what is left in the threads. Remove the valve covers. Now all the head bolts are exposed. Fastest way to remove, Impact wrench.

 

[outsider]

I've also been told you should remove the bolts in the reverse of the torque order to prevent the head from warping but that might not be a big deal with these old heavy heads.
Might want to do it just to be safe since you'll need to know the torque order to put them back on anyways it takes no extra time.

 

[deVille33]

I would still get the SM, but you could use a Motor's, Clinton or other manual for head, manifold, and other parts as a guide for replacement procedures. You can remove the head bolts by loosening with the outer bolts and working toward the center. Essentially the same as reverse sequence. Clean the parts and inspect the parts as you remove them. Check the bolts for thread damage and check the bodies for stress indications. The bolts used on these engines were superior to the bolts used on todays engines, which are designed with one time stretch tensions, but do not use any bolts that cannot pass a visual inspection. Check the threads in the block for possible damage also. You can use a thread cleaner/chaser to remove stress burrs and foreign materials in the threads in the block. Check the deck surface for any signs of thread pulls. You can ensure the deck is true using a straight edge and feeler gauges. The description of how to do would be in any of the manuals I mentioned. You can correct slight imperfections of the deck using a wide flat bastard file.

 

[68devil]

Doing this right now on mine. It was a lengthy process. You do have to take everything off like mentioned. Also get the Cadillac manual as the chiltons is garbage. It gives you maybe 12 steps to get it out and those are vague at best. Also it tells you to take the trans and engine out together. That's not possible and I knew that before I tried. Hence why I got the original manual. Best of luck.

 

[outsider]

it absolutely is possible to take the trans and engine out together. I did it on my 69 Calais, plenty of pictures in my restoration thread.

 

[jayoldschool]

Zero chance of warping that head on bolt removal. Blast them out with a gun.

 

[68devil]

it absolutely is possible to take the trans and engine out together. I did it on my 69 Calais, plenty of pictures in my restoration thread.

Maybe so but the 68 manual says to take the engine out by itself.....

 

[chrisntam]

Took the engine out of my '70 with the trans in tow. Couldn't get the engine separated from the trans, so both had to come out. FSM instructs to remove engine only. LOTS easier together!

 

[Jeff R]

Before you do anything, take pictures and then more pictures and then more. No matter what you think, the head will be off longer than you think and you will be amazed at what you forget.
Jeff

 

[the APEMAN]

Forget about taking exhaust manifolds off while the heads are still on the engine unless they have been off recently. Nearly impossible. Pull the heads and manifolds together. Spray brake fluid on the exhaust flange studs 2 or 3 times ahead of the job by at least a few days.

 

[Jeff R]

Use a 50/50 mix of ATF and acetone. It will loosen just about everything.
If you have an old bottle of Ford ATF you can use that, I won't tell!!
Jeff

 

[the APEMAN]

For flange bolts/studs OK. For exhaust manifold to head bolts the problem is you cannot get liquid to reach the threads. Machine shops can do better.

 

[deVille33]

As bdude has not replied, I think we are discussing this among ourselves. For the exhaust bolts or any badly rusted bolts, I like the ATF and acetone solution that Jeff R mentions. Brake fluid works, but is messy and strips paint. If you can get an impact unit to fit into the space and the bolt heads aren't rounded and deteriorated, you will have better luck removing the bolts without snapping them.
With these older models, the transmissions were longer and clearance becomes a problem when removing the engines with trans complete. You have to raise the front of the car to gain space for the trans to clear the firewall and the floor. Get the engine high enough then move the car back or the engine forward. This is where those center shifters with the screw shafts come in handy for repositioning the lift angles. You can remove the trans first, but that makes for 2 times the work.

 

[bdude273]

As bdude has not replied, I think we are discussing this among ourselves. For the exhaust bolts or any badly rusted bolts, I like the ATF and acetone solution that Jeff R mentions. Brake fluid works, but is messy and strips paint. If you can get an impact unit to fit into the space and the bolt heads aren't rounded and deteriorated, you will have better luck removing the bolts without snapping them.
With these older models, the transmissions were longer and clearance becomes a problem when removing the engines with trans complete. You have to raise the front of the car to gain space for the trans to clear the firewall and the floor. Get the engine high enough then move the car back or the engine forward. This is where those center shifters with the screw shafts come in handy for repositioning the lift angles. You can remove the trans first, but that makes for 2 times the work.

Yeah I haven't replied because I had a miniature heart attack while reading over the steps haha. I think I'll skip the head removal and just take it to a shop to get the stem seals replaced. Any idea how much it would cost? I give up on the stem seals they have literally killed me and I need to have this car running properly by July 19.

 

[drmenard]

Valve seals can be replaced without taking the motor out, or even taking the heads off... If your careful don't even have to take off the intake... Just need a air compressor and hose to pressurize the cylinder and a spring compressor to take the keys off the valves and but the new seals...Not too hard if you know what to do..

 

[bdude273]

Valve seals can be replaced without taking the motor out, or even taking the heads off... If your careful don't even have to take off the intake... Just need a air compressor and hose to pressurize the cylinder and a spring compressor to take the keys off the valves and but the new seals...Not too hard if you know what to do..

I do know what to do. The problem is I cannot get the cylinders to TDC because the flywheel cover won't come off without me grinding the head off of one of the bolts+removing the starter and I can't find a bolt for the crank pulley anywhere. I'm just annoyed about it and am going to do the heater core on my own and have these done professionally.

 

[drmenard]

this is what I do.. I take off the rocker covers.. and anything that has to come off to get them off.. Then take out all the spark plugs.. now take off all the rockerarms and keep them in order with the pushrods ..Now screw the hose into the spark plug hole.. Now connect the air to the hose.. The air will push the piston all the way down and keep the valves from moving.. Now compress the springs and change the seals... Next cylinder same thing.. No need to do more than that...

 

[the APEMAN]

Are you 100% sure the valve stems are in need of repair? This is very unusual for a Cadillac engine.

 

[bdude273]

this is what I do.. I take off the rocker covers.. and anything that has to come off to get them off.. Then take out all the spark plugs.. now take off all the rockerarms and keep them in order with the pushrods ..Now screw the hose into the spark plug hole.. Now connect the air to the hose.. The air will push the piston all the way down and keep the valves from moving.. Now compress the springs and change the seals... Next cylinder same thing.. No need to do more than that...

So you're saying I shouldn't drop a valve if all I do is stick the hose in the spark plug hole and fill it with air? Any particular order? I've got the spark plugs out.

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Are you 100% sure the valve stems are in need of repair? This is very unusual for a Cadillac engine.

100%. I found bits of them under the valve (or rocker) covers.