Installing Y pipes

rebars1

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I'm getting ready to replace the Y pipes in my 1971 Trisonic merc 888, Ford V8 302. I have new O rings and bolts, but should I also use a sealant between the exhaust separator and transom plate, and also between the exhaust separator and the side pipes? If so, what sealant should I use? Since my current leak is at one of the joints, I want to make sure it stays sealed, and the O rings just don't seem like they would be enough.
 

WillyBWright

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Re: Installing Y pipes

O-rings are amazing things when the sealing surfaces are good. If they're badly pitted from corrosion, then forget the o-ring and use a healthy bead of Ultra or RTV Silicone. If the surfaces are good, a better idea would be a light coating of grease for the o-ring. Loctite the bolts.
 

Don S

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Re: Installing Y pipes

I agree with using the Ultra if the surface is corroded, but I would also use the o-rings.
 

rodbolt

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Re: Installing Y pipes

hello I dont like RTV especially under the waterline. it has a tendancy to attack aluminium and accelerate corrosion here in the salt pond. use 3m super weather strip adhesive or OMC gel-sealII or its loctite equivalent. I Have had to many problems with silicone below the waterline.<br /> good luck and keep posting
 

rebars1

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Re: Installing Y pipes

Wow. Thanks for the input guys, but I see there are differring experiences with various products. I went to West Marine and they had Ultra Blue, Ultra Black, 3M 4000, 3M 5200, and some others. They all look good on the labels. Can anyone explain the differences and preferred sealant (in addition to the O rings) to use on the flanges of the Y pipe pieces? What does RTV mean? <br /><br />rodbolt: which 3M do you prefer? Is it ok with the Y pipe temps?
 

rebars1

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Re: Installing Y pipes

Can anyone explain the uses of the products in my previous post and which would be the best choice for this application? Also, where can I get OMC gel-sealII and Perfect Seal?<br /><br />Thank You.
 

Scaaty

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Re: Installing Y pipes

RTV means room temperture vulcanizing,i.e., cures at room temps once outside the tube
 

rodbolt

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Re: Installing Y pipes

rebars1<br /> most silicone sealents are not rated for use below the waterline. the 3m scotchgrip or yellow weatherstrip adhesive is a permanant hardening sealant. usually the bond of silicone to aluminium is not good when oils are present, couple that with the corrosive effects of hot exhaust gasses and sometimes the seal is comprimised. most orings and flanges below the waterline have a specific adhesive called for in the manual but bellows adhesive,scotchgrip omc adhesive M and 3m super yellow all have the same basic properties. sealer 1000 is rather watery but works as well. I get my sealants from a friend at the bombardier dealer
 

rebars1

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Re: Installing Y pipes

Thanks for the great information! I appreciate the wisdom and knowledge you share with us rookies. I'll let you know how it goes.
 

rebars1

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Re: Installing Y pipes

Is Loctite Red the appropriate material to use on the bolts?
 

Don S

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Re: Installing Y pipes

No, the red Loctite is not the appropriate material to use.<br />Something like Permetex 2H or even grease to prevent corrosion is all you need on the bolts. Have never, ever seen one come loose on it's own. All you need is something to help prevent the oring from leaking in case the castings are corroded. The Permetex 2H will work for that too, unless the corrosion is real bad, then you need new parts or some epoxy to patch the gaps with.
 
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