1950s Quick exhaust manifold question (1959)

[Cadillac Jack 82]

How easy or difficult is it to replace the exhaust manifold gaskets in a 59 Cad?  Is it something that can be done in a day or does it involve more work?  Just curious as I'd like to replace mine when a new shop fixes the exhaust, but I don't want them having the car overnight or over the weekend.

[1959Fleetwood]

Hello Tim, renewing exhaust manifold gaskets is a straight forward job but when it comes to the time that is needed to do the job lays mainly on your own or somebody else's skills and how many components you have to remove from the engine and the manifolds itself. If you have a plain engine with no accessories than its an relativity easy job. You then only have to remove the generator and the brackets at the rear of the power steering pump and disconnect the front exhaust pipes. On the other hand, if your car has for example an air-ride compressor with the power steering pump attached, cruise control unit and airconditioning pump and lines you have to remove these components first to gain acces to the manifolds itself. Also the job is easier to do when you have a hoist, this for disconnecting the front exhaust pipes and the rear bolts from the manifolds to the cylinder heads especially for the bolts at the drivers side of the car due to the steering column that blocks good acces. The old bolts can be tricky to come loose mainly because of rust and carbon between the bolt holes and bolt. Use good quality tools with a 6 point hex instead of the 12 point hex. Old hex head bolts are prone to an uneven surface due to rust witch can cause a 12 point socket or wrench to slip over it.
I always check the manifold gasket surfaces for warping witch is a common practice, a good machine shop can make them prefect flat again so the gaskets will fit tight. After finishing the job i also make a test run with the car to heat up the manifolds and gaskets including the front pipe gaskets, then let the engine cool down (overnight) and retighten all the bolts starting with the center bolts and working to the left left and right and the nuts for the front exhaust pipe to the manifold. So, yes it can be an easy job but on the other hand you can come across some difficulties during the proces     
Hope this helps

[Cadillac Jack 82]

Hello Tim, renewing exhaust manifold gaskets is a straight forward job but when it comes to the time that is needed to do the job lays mainly on your own or somebody else's skills and how many components you have to remove from the engine and the manifolds itself. If you have a plain engine with no accessories than its an relativity easy job. You then only have to remove the generator and the brackets at the rear of the power steering pump and disconnect the front exhaust pipes. On the other hand, if your car has for example an air-ride compressor with the power steering pump attached, cruise control unit and airconditioning pump and lines you have to remove these components first to gain acces to the manifolds itself. Also the job is easier to do when you have a hoist, this for disconnecting the front exhaust pipes and the rear bolts from the manifolds to the cylinder heads especially for the bolts at the drivers side of the car due to the steering column that blocks good acces. The old bolts can be tricky to come loose mainly because of rust and carbon between the bolt holes and bolt. Use good quality tools with a 6 point hex instead of the 12 point hex. Old hex head bolts are prone to an uneven surface due to rust witch can cause a 12 point socket or wrench to slip over it.
I always check the manifold gasket surfaces for warping witch is a common practice, a good machine shop can make them prefect flat again so the gaskets will fit tight. After finishing the job i also make a test run with the car to heat up the manifolds and gaskets including the front pipe gaskets, then let the engine cool down (overnight) and retighten all the bolts starting with the center bolts and working to the left left and right and the nuts for the front exhaust pipe to the manifold. So, yes it can be an easy job but on the other hand you can come across some difficulties during the proces     
Hope this helps

Great advice thank you.  Luckily, I don't have air ride, AC, or anything other than the standard accessories.  I'm hoping this will be a pretty straight forward job.

[Big Fins]

And the $2.00 question is...Have the bolts ever been out before? Yes? How long ago?
Never? Spray them 3 times a day for week with PB Blaster. Then be very careful.

It's not something you can just tell anyone. It's a feel in how the metal is responding to the wrench and the force applied to it.

I did my original '59 bolts just like and they walked out with no breakage.

[Cadillac Jack 82]

Good question I'm guessing they've never been out before, however, She did receive a partial exhaust job in...get this 1968 (Kmart).  Everything looks clean and she's never sat outside so I'm hoping a good dose of PB will help.

[Big Fins]

I went through a couple of cans just to be on the safe side. It was an Cali native car and clean, just needed a freshening up.

[Cadillac Jack 82]

Yeah I'd like to resolve the ticking noise I have.  Its definitely not the valves.  It 100% sounds like the 64 did before I replaced the gaskets on the exhaust manifold.  She needs to sound like a Cadillac and not a tractor.

[The Tassie Devil(le)]

If the gaskets have been leaking for a long time, then you might find that there is a lot of corrosion around the exhaust port in the head, or the manifold.

It could mean that you might have to get the manifold planed to make the gasket surface completely flat to enhance gasket sealing.

But, as others have said, getting the bolts out is going to be the hardest.   Plus, it might be necessary to remove the engine pipe of the exhaust system to reseal everything.

As for doing it in a day, all being well, it can be done in a couple of hours.

Bruce.

[dn010]

For the bolts, I personally find that running the engine to heat things up prior to removal does the trick every time. Yea, it sucks working on stuff that is hot but I've never had one bolt seize or break on me once the engine was warmed up. This includes bolts or 02 sensor port plugs that were stuck when trying to remove cold; once hot - no problem.

The studs on the other hand may be where your problems lie. With any luck heated, they'll thread out of the manifold and you can deal with them on the bench.

[Cadillac Jack 82]

Thank you everyone for the help.

[Big Fins]

For the bolts, I personally find that running the engine to heat things up prior to removal does the trick every time. Yea, it sucks working on stuff that is hot but I've never had one bolt seize or break on me once the engine was warmed up. This includes bolts or 02 sensor port plugs that were stuck when trying to remove cold; once hot - no problem.

The studs on the other hand may be where your problems lie. With any luck heated, they'll thread out of the manifold and you can deal with them on the bench.

I thought that O2 sensors were the worst. Never tried the 'get it hot' trick first.

[David King (kz78hy)]

In the event of a missing bolt or incorrect ones, I have new bolts available.  These are a special bolt.  One size under head for the shank size.

https://keepemrunningautomotive.com/shop/ols/products/1463110

[Cadillac Jack 82]

Yeah my manifold is definitely leaking badly.  You can see the gases and smell it from the engine bay.  At least the exhaust has been fixed and hung right.

[Cadillac Jack 82]

Fixed

[59-in-pieces]

David,

Very nice set of replacement bolts with what looks like the proper bolt head design - often missing from other aftermarket, or over the counter bolts.

One question - and by no means a criticism - did you emboss a "makers mark" on the surface of the head, similar to the OEM bolts.

And finally, these bolts can be used in models other than Broughams, as the title might not suggest, correct.

Have fun,
Steve B.

[David King (kz78hy)]

Steve,

The bolts are correct to print, but no makers mark.  Once installed, you can't see them anyway.  These are a common bolt used from '56 to'67.

[Clewisiii]

Best image I have of the bolts David sells.  I cannot find the photos of me installing my manifolds. I think since I was using the high heat copper gasket sealant on the manifolds, I avoided using my phone for pictures. To messy.

[Cadillac Jack 82]

I'm planning on having a resto shop do these that are down the street from where I keep Shelley so I avoid any damage to my car driving it elsewhere.  They also specialize in classics and have a 5 star rating.  Might cost a bit more but at least it'll be done right.

My follow up question is do I go with the standard paper/metallic gaskets or copper ones?

[Lexi]

And the $2.00 question is...Have the bolts ever been out before? Yes? How long ago?
Never? Spray them 3 times a day for week with PB Blaster. Then be very careful.

It's not something you can just tell anyone. It's a feel in how the metal is responding to the wrench and the force applied to it.

I did my original '59 bolts just like and they walked out with no breakage.

Well said. Clay/Lexi