man_btc
03-17-2020, 02:12 AM
CANNOT REPLY TO OP - NOT AN ORIGINAL TOYOTAVANTECH POST. Copied FYI from archived Yahoo Previa Group files.
Photo Album "removing-a-cylinder-head-at-the-salvage-yard" by Corey Hageman (cmh11294) related to a discussion about finding a head without cracks.
Covers all the bases of getting a head off...
****CAVEAT***
Keep in mind this includes a hack or two related to the fact that this is on a salvage yard vehicle. For instance, note that "prying up the floor" above the intake manifold is not necessarily desirable if you are working on your van and have dropped the engine by removing the engine mounts (and replacing each with a much thinner piece of wood).
Here's the text from a post out of the 44-post thread - some of the Yahoo file structure left in. the original date is in another reply to the gray-text as "postDate": "1373662493" but I don't know how to interpret that.
"prevInTopic": 52494,
"nextInTopic": 52503,
"prevInTime": 52501,
"nextInTime": 52503,
"topicId": 52478,
"numMessagesInTopic": 44,
"msgSnippet": "I had the same experience at the junkyard, lots of cracked heads, and gave up finding a good one. Started calling machine shops that could weld the crack on",
"messageBody": "<div id="ygrps-yiv-2022144720">I had the same experience at the junkyard, lots of cracked heads, and gave up finding a good one. Started calling machine shops that could weld the crack on mine. The welding itself was not that expensive($80). The rest of the rebuild added a lot more than that. Three years later it is still running well.<br/>\n<br/>\nI was leery about the effectiveness of welding an aluminum head, but the guy said they did it all the time successfully. In my case he was correct. So, if all else fails in finding a replacement head, this is just one more option.<br/>\n<br/>\nGood luck,<br/>\n<br/>\nSteve<br/>\n<br/>\n<blockquote><span title="qreply"> --- In <a rel="nofollow" target="_blank" href="mailto:previa@yahoogroups.com">previa@yahoogroups.com</a>, "
cmh1129 wrote: I took the opportunity toast month to spend a week working with and sharing Previa knowledge with Sammay up in Seattle . he showed me how to change the head gasket with the engine still in the van. One thing that surprised me was the percentage of cracked heads that accompany a blown head gasket. Seems that about 8 out of 10 blown head gaskets are accompanied with a cracked in the head . We all know that the head gasket failure is the ultimate demise of the Previa. It seems to me that the best preventative maintenance we can do is to change the coolant and flush the system on a regular basis. Also, at the first sign of a gasket failure is NOT LET IT OVERHEAT!! I have the chance to buy a very nice , rust free, low milage (154k) van for super cheap. It has a blown head gasket , and most likely a cracked head. I have pulled 3 heads here in Colorado for a replacement, and they have all been cracked. And the crack is not very obvious either. Very small between the valves. I have a lead on a head from a van that is being parted out cause of a front end collision. I'm pretty sure that one will be good ... I am attaching some pics of the head I pulled today. Looking at the cylinders, you can tell which one had the crack in the head.
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Photo Album "removing-a-cylinder-head-at-the-salvage-yard" by Corey Hageman (cmh11294) related to a discussion about finding a head without cracks.
Covers all the bases of getting a head off...
****CAVEAT***
Keep in mind this includes a hack or two related to the fact that this is on a salvage yard vehicle. For instance, note that "prying up the floor" above the intake manifold is not necessarily desirable if you are working on your van and have dropped the engine by removing the engine mounts (and replacing each with a much thinner piece of wood).
Here's the text from a post out of the 44-post thread - some of the Yahoo file structure left in. the original date is in another reply to the gray-text as "postDate": "1373662493" but I don't know how to interpret that.
"prevInTopic": 52494,
"nextInTopic": 52503,
"prevInTime": 52501,
"nextInTime": 52503,
"topicId": 52478,
"numMessagesInTopic": 44,
"msgSnippet": "I had the same experience at the junkyard, lots of cracked heads, and gave up finding a good one. Started calling machine shops that could weld the crack on",
"messageBody": "<div id="ygrps-yiv-2022144720">I had the same experience at the junkyard, lots of cracked heads, and gave up finding a good one. Started calling machine shops that could weld the crack on mine. The welding itself was not that expensive($80). The rest of the rebuild added a lot more than that. Three years later it is still running well.<br/>\n<br/>\nI was leery about the effectiveness of welding an aluminum head, but the guy said they did it all the time successfully. In my case he was correct. So, if all else fails in finding a replacement head, this is just one more option.<br/>\n<br/>\nGood luck,<br/>\n<br/>\nSteve<br/>\n<br/>\n<blockquote><span title="qreply"> --- In <a rel="nofollow" target="_blank" href="mailto:previa@yahoogroups.com">previa@yahoogroups.com</a>, "
cmh1129 wrote: I took the opportunity toast month to spend a week working with and sharing Previa knowledge with Sammay up in Seattle . he showed me how to change the head gasket with the engine still in the van. One thing that surprised me was the percentage of cracked heads that accompany a blown head gasket. Seems that about 8 out of 10 blown head gaskets are accompanied with a cracked in the head . We all know that the head gasket failure is the ultimate demise of the Previa. It seems to me that the best preventative maintenance we can do is to change the coolant and flush the system on a regular basis. Also, at the first sign of a gasket failure is NOT LET IT OVERHEAT!! I have the chance to buy a very nice , rust free, low milage (154k) van for super cheap. It has a blown head gasket , and most likely a cracked head. I have pulled 3 heads here in Colorado for a replacement, and they have all been cracked. And the crack is not very obvious either. Very small between the valves. I have a lead on a head from a van that is being parted out cause of a front end collision. I'm pretty sure that one will be good ... I am attaching some pics of the head I pulled today. Looking at the cylinders, you can tell which one had the crack in the head.
10034
10035
10036
10037
10038
10039
10040
10041
10042
10041
10043
10044
10045
10046
10047
10048
10049
10050
10051
10052
10053
10054
10055
10056
10057
10058
10059
10060
10061
10062
10063
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