Book11

AEROBUS

Chapter 11 - REPLACING A SIMPLE GASKET

I opened the hood and saw the job of replacing the exhaust manifold gaskets was going to be fairly easy due to the accessibility of the work area. I couldn't have known everything else would go wrong eventually, including accessibility.

Before beginning I noticed a lot of caked-on oil around the manifold. This is nearly always the result of the valve cover gaskets leaking the oil they are supposed to contain. The valve covers sit just above the exhaust manifolds.

For the non-mechanically experienced reader I will try to simplify what I am about to describe. The Aerobus is equipped with a V-8 engine. It's called that because the working parts of the engine, the cylinders, are arranged in a "V" shape and there are 8 cylinders in the engine, 4 on each side of the V.

At the top, or "head" of each side of the V there is a valve cover. It covers the valves that are part of the head. There is a lot of oil circulating up there for lubricating the moving parts and the covers keep it all enclosed. The covers on a small-block Chevy often have a cork gasket that's supposed to make a seal around the point where the cover mates with the head. The cork gasket often dries up and doesn't seal well. When that happens a little oil can seep out and run down the engine. This can make a mess as it accumulates over a hot engine and bakes itself on.

There are two exhaust manifolds. One bolts to each head at the outside of the V. Where they join the head there is normally a gasket as well. On the other side of the exhaust manifold there is another gasket connecting it to the exhaust pipe that was just replaced on Bud.

It was the gasket between the manifold and pipe the muffler shop said they replaced and the gasket between the manifold and head they said still needed to be replaced.

I could tell my valve covers needed new gaskets from all the accumulated oil on the engine. I decided to replace them at the same time I did the exhaust gaskets. A lot of the same interfering brackets and bolts would have to be moved for both jobs so it only made sense to do them at the same time.

I soon discovered two major components interfered with replacing the valve cover on the driver's side. The brake master cylinder, I just replaced, had to come out along with the air conditioning compressor. I really didn't want to remove the master cylinder again since I spent so many hours installing it and bleeding the air from the system. I considered all alternatives and eventually concluding there was no way around it. The master cylinder had to come out. The air conditioning compressor merely had to be moved out of the way while remaining connected to its hoses.

I removed all the interfering parts and the valve covers came off easily enough. It was a lot of preparation for a simple job. The covers were very clean inside which tended to confirm the odometer reading of a little over 50,000 miles. I cleaned the outside of the covers with solvent, repainted them the original orange color and mounted new cork gaskets on them.

Next off were the exhaust manifolds. Some of the bolt-like studs at the bottom of the manifold were very hard to remove and I broke one trying to get a nut off of it. This is fairly common because the studs are brittle and rusty from continued exposure to heat and splashing road water down there.

When the manifolds were off I noticed there were no gaskets at all between them and the head and the gaskets the muffler shop said they replaced were in very poor condition and obviously weren't replaced. I really began to wonder what the shop did. They certainly didn't replace the gaskets they charged me for. They obviously hadn't removed the nuts or they would have broken the stud the same way I did. I saved all the old parts to show the muffler shop when I went back.

I needed more gaskets and at least one stud. I decided to replace all three studs on each manifold since if one was brittle enough to break then the others must be weak as well.

Finding replacement studs is easy. I bought a set and proceeded to remove the old ones. I did this by clamping the manifold in a bench vise and employing a special stud-removal tool on them one at a time. The three studs on one manifold came out fine but those on the other manifold gave me little trouble. They all broke off flush with the manifold so I was left with nothing to grab on to in order to try and twist them out.

To continue I drilled a hole down the center of the pieces of stud that were still in the manifold. I started with a tiny drill bit and gradually worked up using incrementally larger bits until I had as big a hole as I could drill without destroying the threaded part of the manifold. I then inserted a small tool known as a screw extractor into the hole I drilled. In two cases the piece cooperated and came right out with the tool. The one remaining stud remnant was apparently stuck a lot faster than the others.

I worked the extracting tool in further and tighter on that last stud and put all my strength into turning the tool. Finally after much effort it freed itself with a loud report. Aaah, success. Or was it? What was this?

I couldn't believe what I was seeing. The whole corner of the cast iron manifold snapped off! Instead of the stud finally freeing its grasp, it took the corner of the manifold with it. I fumed loudly for a few minutes. My simple gasket replacement job was turning into a nightmare. I needed a new manifold.

Manifolds are fairly common in junkyards and I knew it wouldn't cost me much to get one. I just hated the inconvenience at this point. I wanted to complete this job and get back to the muffler shop with Bud and get some restitution. It was too late on a Saturday for a junkyard to be open and none in my area were open on Sunday so I was through for that weekend.

"How much for a ram's-horn manifold?" I asked the junkyard counterman the following Friday afternoon, using mechanic's shorthand to express the type of exhaust manifold I needed.

"Smog or not?" he responded, referring to whether the car was equipped for California smog equipment.

"Smog."

"Seventy-five bucks each."

"Gawd that's high! How much without smog?" I asked, figuring I could go without the required smog equipment.

"Oh that would be one hundred each."

"Why so much?"

"Ram's-horns are hard to find. Everybody in the world wants them and GM gets two-fifty each for the new ones."

I thanked the guy and left figuring he was just trying to take advantage of me. I checked four more junkyards that day and got the same answers except they didn't even have any for sale. They were truly hard to find. I didn't want to pay these prices and I felt there must be some other alternative. I went back to the rod and custom shop to see if they had any manifolds or ideas for mine. They didn't have any but they did recall the customer who purchased my engine indicated he was going to replace the manifolds with headers when he installed the engine in his car they were building for him. Headers are after-market exhaust manifolds that give hot rods more power and are often chrome plated for appearances.

"Okay, tell him I'd like to buy the left-hand manifold from him."

"All right, he's supposed to come see me in the middle of the week. I'll ask him and let you know."

I called the shop many times that week and the next before I finally got an answer.

"He wants fifty dollars for the pair."

I felt betrayed because I gave the owner such a deal on the engine. If he didn't need the manifolds I expected him to just give them to me. Of course, my junkyard experience taught me I was still getting a bargain so I agreed to the price and went to get them.

Fortunately the replacement manifolds surrendered their studs with little effort and I was able to install one on Bud and save the other as a spare. To this day I still have the other manifold I bought back. I may never need it but I'm not letting go of it. I learned a valuable lesson about getting rid of parts, a lesson that was soon to be repeated.

I reconnected the exhaust system using all new gaskets and was anxious about getting back to the muffler shop that took some advantage of me and caused all this grief.

As I was putting one of the valve covers back on I noticed a push-rod had come out from under a rocker-arm. If you are unfamiliar with the internal parts of an engine bear with me for a moment. I need to describe this in somewhat technical terms for the benefit of those readers who are familiar with the terms. The rest of you will still be able to appreciate my frustration.

So the push-rod was sitting off at a funny angle and not in the pocket of the rocker arm. The valves and springs were in good shape. The only conclusion I could come up with was that a lifter collapsed allowing the push-rod to jiggle around and get out of position.

The only way to determine if a lifter collapsed and then correct it was to tear the engine down further. I removed the carburetor and intake manifold. I used the opportunity to clean the intake manifold and paint it the same orange color I used on the valve covers. At least the whole top of my engine would be freshly painted when I got it back together.

I didn't see anything physically wrong with my lifters, not even the one I suspected as failing. With only 50,000 miles on this engine there shouldn't have been anything wrong with them. Having dismantled the engine further I could see a lot more of the interior of it and was pleased with how remarkably clean it was, lending further proof to the validity of the low mileage on the odometer. Since I went to the trouble of dismantling the engine that far I replaced all the lifters anyway.

It occurred to me then I gave away a brand new set of lifters and push-rods in exchange for the machine shop work on the Fiero. They were parts I carried around with me for many years and didn't need. That is until very soon after I got rid of them. I vowed that day not to get rid of another car part for the rest of my life, a resolution I didn't share with Vilma.

Installing lifters and push-rods requires adjusting the valves afterwards. In doing that I found no matter how much I tightened the rocker arm nut, where the push-rod originally slipped out, it wasn't getting tight. I kept tightening the nut and not getting any results until I noticed the rocker arm stud I was working on was longer than all the others on the head. Now I knew what the problem was. The stud was pulling out of the head. I worked on it some more and managed to completely remove the stud from the head. Much to my chagrin a big arc of antifreeze ejaculated from the stud hole that was apparently machined into the water-jacket of the head. I quickly jammed the stud back in realizing I would need to drain the antifreeze before proceeding further.

It turns out the threaded stud isn't threaded into the head but merely anchored there by pressure when the head was manufactured. I never heard of one pulling out before.

What I am relating here over a few pages actually took me over a month of part time tinkering on weekends, interspersed with theoretical conversations with friends and more experienced back-yard mechanics whenever I encountered them. Through it all I was still not getting back to the muffler shop. Each new wrinkle caused me to seek the opinions of more experienced people, from parts countermen to working mechanics.

My withdrawn rocker arm stud was a first for many of those with whom I conferred. Some said I could remove the heads, thus tearing the engine down even further, and have a new stud actually threaded in or I could buy a slightly oversized stud and hammer it in. I chose the latter and with much searching found a parts store that had one three-thousandths of an inch larger; less than the thickness of a page of this book.

I took the slightly thicker stud home and hammered it into the head. I put the rocker arm and nut on and proceeded to tighten. Once again as I tightened the nut the new stud gradually pulled out. I was extremely disappointed by this. I just wanted to get this engine running again. I wasted a month's effort diagnosing the problem. I wasted my money on new lifters, which weren't the problem. I dismantled my engine far further than was necessary. I felt I endured enough.

Out of frustration I took the largest sledgehammer I owned and started wailing on the defective stud. I must have been making quite a racket because Vilma came out and offered some encouragement.

"Go ahead and smash it up, then you can get rid of it and work on the Fiero."

I pretended to ignore her contribution and continued to beat the stud in earnest until my arms ached. That seemed to satisfy and relieve me. It was no longer as important if that bastard stud wouldn't stay in. I rested for a long time just sitting silently. The kind of contemplative time that would have been perfect for a cigarette if I hadn't given them up twelve years prior.

Once I thoroughly relaxed I stood up and put the rocker arm and nut back on the offending stud and began tightening again. I kept turning the nut but the stud didn't lengthen this time. It was holding finally.

I got it as tight as I dared and started the engine again. With it running I was able to make a fine adjustment on the nut and it quieted down and started performing as well as the rest. Bud lived again and ran quietly. I could go back to the morons at the muffler shop and get some satisfaction. I decided to require them to re-weld a few spots and turn the tailpipe down some so it wasn't as close to my newly re-chromed bumper. They owed me that work for their incompetence.

At work the following Monday I learned about a transfer I was to take from Sacramento to Monterey, California. The Air Force recently selected me for promotion to Chief Master Sergeant, conversationally referred to simply as, "Chief". The promotion carried with it a requirement to relocate. McClellan Air Force Base in Sacramento was closing so I knew my days there were numbered anyway. I asked to remain in California for another tour expecting to be reassigned to one of the two big bases in Northern California. When the Air Force offered me Monterey I was thrilled.

The assignment would make me the superintendent of the Air Force unit at the Defense Language Institute. The Army, Navy, Air Force and Marines all sent people there for training. If a person is in the military and has a job-related need to learn a foreign language they almost always learn it there. The Air Force had about 1,000 trainees there and I would be the ranking enlisted person. The "Chief". It was a great job in an excellent location so I jumped at it. There was just one catch. I had to be there in six weeks.