Logo
FULL SITE MENU

Osco Risers leaking at Stud

M

makomike1

Contributing Member
Hello all. I have crusader 270 hp log style manifolds. I replaced manifolds,risers and elbows in March 2013. Put everything to gether ran motors and I have a slite water drip coming from behind the riser bolts.Everything torqed correctly. I used all new mounting hardware. I thought I may have did something wrong so I gave it to my marina mechanic to fix. He took risers off put all new studs and gaskets back on and we ran the boat, and we still had a littlte drip coming from the riser stud bolt. Manifolds,risers and elbows were OSCO. I called OSCO and they were no help. Called the store where I bought them, they basically said they will stop leaking over time cause the rust will seal them eventually. Not the answer I wanted to hear. I want it right.So I was thinking about getting a set of BARR risers and see if they are designed any differant and would work. Any suggestions. Has this happen to anyone else. Thanks Mike
 
Osco sells copper washers for sealing. were they used under the stud nuts? I'm not sure what you call a stud bolt. Should be a stud, a copper washer, and a self locking nut.
 
Yes I used all new washers and locking nuts. ( sorrry I meant to say leaking behind the nut)I used new washers and nuts the first time and when the mechanic tried to fix he used all new washers and nuts also. Any help Thanks Mike
 
The two mating surfaces should seal with the correct gasket.

What if the leak is due to a casting fracture that was not seen during product inspection?

I think that I would inspect these more closely.... perhaps pull them and have them Magna-fluxed.
March of 2013 is pretty darn recent. If a crack is found, call on Osco for a warrantee claim.


.
 
I was told by supplier to tighten the studs as tight as i can before stud breaks. and was told to not worry about it cause in a month or to they will rust and seal themselves. Now that great customer service. This sucks
 
I think it is basically a very poor design. The area where the mounting stud goes through the riser is open to water and those copper washers are suppose to seal the area between the bolt and the riser. The plastic insert in the nut is suppose the seal the threads of the stud. Neither the washers or nuts should be reused.

Inspect the dripping very closely to see if you can determine if the water is from behind the washer, behind the nut, or in front of the nut. If between the washer and the riser, perhaps the riser surface was not perfectly flat and the washer is not able to seal it. All surfaces need to be burr free.
 
If the water can drip downward into the exhaust passages, it will flow down and into th exhaust ports.

Good luck with this. I've gone through HELL with such problems with my 360 Chryslers.

Jeff
 
erich said:
I think it is basically a very poor design. The area where the mounting stud goes through the riser is open to water and those copper washers are suppose to seal the area between the bolt and the riser. The plastic insert in the nut is suppose the seal the threads of the stud. Neither the washers or nuts should be reused.

Inspect the dripping very closely to see if you can determine if the water is from behind the washer, behind the nut, or in front of the nut. If between the washer and the riser, perhaps the riser surface was not perfectly flat and the washer is not able to seal it. All surfaces need to be burr free.
Click to expand...

yeah, agree with all this. I'd try some ultra copper or ultra black squished into the stud area with the washer removed. reassemble. Note that the issue might be the studs didn't get thread seal before they were screwed in. Some castings are drilled thru into the actual water passage so you have the threat of water backing out of the threads.
 
It's easy enough to see how leakage would occur as the stud goes through the open area of the riser. I've never had them leak around the stud. usually leakage will be at the gasket mating surfaces. You could put some permatex black on the threads to help seal. Also did you use anti seize on the studs?
 
Back
Top