Author Topic: removing rusted manifold collector bolts  (Read 1171 times)

Offline JIM W

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removing rusted manifold collector bolts
« on: August 04, 2020, 12:04:24 PM »
I just recently bought a 1985 dual wheel C30 dump truck with a 350ci and the exhaust system is in rough shape.  The doughnut is missing on the passenger side and the heat riser is loose and rattling around.  I want to get the nuts off the three long bolts on the collector but they are rusted fast and look like they have been there for decades.  Everything is too oily and greasy to risk heating them with the torch so I have been soaking them with PB Blaster.  I cannot move them with my socket wrench and wondered if I dare to try work them back and forth with the impact wrench set on low?

Assuming the bolts just break off has anyone used the repair clamps made by Nickson Industries #15111 / 15113 or similar?  I am not sure there will be room to get them over the end of this manifold but, if it does, it may be the easiest way to reconnect the downpipe. I just need to get the existing bolts out or broke off with out damaging the manifold itself.  I toyed with the idea of just taking the manifold off so I can properly fix it but those little 10mm manifold bolts are sure to break off in the head and I will be worse off.

I wondered how others have got past this problem?  Thanks for any suggestions.
JIM

Offline VileZambonie

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Re: removing rusted manifold collector bolts
« Reply #1 on: August 04, 2020, 03:06:37 PM »
Why torture yourself? Just take them off and repair them correctly or replace them altogether.
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Offline JIM W

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Re: removing rusted manifold collector bolts
« Reply #2 on: August 04, 2020, 03:12:55 PM »
I don't think it is wise to put a wrench on the manifold bolts and risk a more major repair.

Offline bigben5054

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Re: removing rusted manifold collector bolts
« Reply #3 on: August 05, 2020, 09:59:54 AM »
I've been down this road a few times.  You just need to remove the manifold and replace the studs properly.  I don't think the manifold-to-head bolts will give you as much trouble as you think.  They are usually in fairly decent shape, not rusted and corroded like the collector studs are.  Take your time and use the right tools.  If they are six point bolt heads, use a six point socket or wrench, get a good clean grip on the bolt before cranking, etc.

Offline JIM W

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Re: removing rusted manifold collector bolts
« Reply #4 on: August 22, 2020, 07:15:13 AM »
Ben; Thanks for the encouragement.  I did finally get the three nuts off and everything reassembled.  The bolts were pretty corroded but I was able to run new nuts up and tighten the assembly with new gaskets.  If it comes loose I may have to double nut it to make up for the poor threads. It's only a site truck so it won't get too much use anyway.

I have a Dewalt 20v cordless hammer drill.  It is made for 1/4" screwdriver bits but I had an adapter to a 1/4 socket and then adapted that to a 3/8 drive socket. I sprayed PB Blaster on the area every day for a week or more and then, using every extension that I had, i could reach a socket up and onto the nuts.  I pounded front and back for a couple of minutes on each nut then sprayed it and tried again the next day.  It took several applications but all three nuts finally came off with out breaking the studs.  The nuts were so tight and the threads so buggered that they came off smoking hot.  But they came off!  I was afraid the air impact would just twist off the bolts and this cordless had just the right amount of torque.

Online JohnnyPopper

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Re: removing rusted manifold collector bolts
« Reply #5 on: August 23, 2020, 01:51:36 AM »
For what it's worth: If you can shock with bolt/nut with a slight jolt from a hammer, you will find the corrosion bond gets broken and will loosen. PB is great for that, but last ditch is to heat with torch.
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