Home Repairs: Fixing a Chevy Van’s Cracked Cynlinder

Posted on 15. Apr, 2010 by Forest in Uncategorized

One of my readers, named Michael Traster, recently wrote to me with some suggestions for the blog. He suggested I talk more about home repairs, emergency repairs and making things last… He also mentioned how he had once fixed a cracked cylinder on his Chevy Van. Even if you don’t have a cracked cylinder this post that Michael provided me, after I asked, shows initiative in a situation where the expensive option was not available.

Thanks a million Michael….

Disclaimer: We cannot be held responsible for anything that happens as a result of home repairs such as the example below and you carry these tasks out completely at your own rish

Around 1985, I owned an old Chevy Van. One day while driving around I noticed the engine light come on.. it was HOT. Out the rear view mirror I saw a huge cloud of white smoke behind me. Next, I said all the
necessary words for such an event, got some water in it and drove home.

I repeated some of my favorite words time, or eleven, for emphasis!

It was a 6 cylinder, so there was only one head and I pulled it off .That took around 2 hours to get to and to remove.
My hope was that it was just the head gasket leaking into a cylinder. As I inspected it, I found no sign of leakage across any of the gasket surfaces. The rear most cylinder wall had a vertical crack in it. The crack was up high and about 1 1/2 inches long.

I couldn’t get the cylinder wall hot enough to braze it… so that was out.

Next I got out a drill and a stone bit and ground a groove up and down along the crack. I had first placed a wet rag over that piston to catch any metal grindings so I could remove them. The groove was perhaps as deep as the thickness of a quarter, and extended past the top and bottom of the crack.

Next I removed all the little metal particles… til there was nothing left from the grinding. After that I
wiped down the cylinder wall with a rag with acetone on it…

I did that several times, til it had zero residue on it from oil.
The next step was to mix up some jb weld and put it in the very rough groove I’d ground out.

I then formed it to conform to the surface of the cylinder…

I then let the j.b. weld begin to harden for a few minutes. The next step was to hand crank the engine (WITH THE ENGINE TURNED OFF AND KEY OUT OF THE IGNITION AND BATTERY DISCONNECTED) one time up and down. This put a perfect ring groove into the J.B. Weld..so it perfectly matched up to the dimensions of the cylinder wall.

Then I let it sit over 24 hrs, put in a new head gasket, re adjusted the valve lifters, and Guess What?

It worked fine… I got thousands of miles out of the engine til the van gave up from some totally unrelated cause.

Now there are no guarantees with such things.. but my experience was successful.

Important steps included:
1. Safety… DISCONNECT THE BATTERY!!!
2. Grind that crack about the depth of a coin… and rough to
make a surface that would help the J.B. to adere to it.
3. Put a rag down there to catch all the metal filings from the grinding.
4. Clean the surface several times with a clean rag with acetone.
( wear safety glasses, and gloves, and keep acetone away from any heat source… IT IS HIGHLY FLAMMABLE AND UNFRIENDLY TO THE LIVER.
5. hand crank the engine to get the ring grooves in the j.b. weld..once it’s tacky but before it is hard..
THIS IS VITAL BECAUSE IF YOU DON’T DO THIS A COLLISION BETWEEN THE RING AND THE HARDENED JB WILL BREAK THE JB, THE RING, OR BOTH..

I PUT THE VAN IN NEUTRAL, AND TURNED THE ENGINE WITH THE FAN BELT. THE EMERGENCY BRAKE WAS ON OF COURSE.

6. Install a new head gasket. This is a must..as I know of no head gaskets that can be re used.
7. Adjust the lifters properly… get specs from the dealership…

This was a long time ago. Money was scarce and this repair cost me less than 50 bucks.. 3 for the JB and 30 + for the head gasket and a bit of tax…

Tags: car repair, cracked head, fixing a broken cylinder, home car repairs, van repair