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Discussion Starter · #1 ·
The 90 degree pipe that is at the back of the head is pretty rusted looking. The opening where the hose sides over it is more like teeth than a smooth edge. I would like to replace it, but my concern is that the threads in the head may not be very clean and I could just bust the pipe and leave the threads in the head. Anyone have this situation and might offer tips ?
 

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John;

Threads in the head are into a massive casting, so there is lots of material there...and that pipe is a fairly thick-walled pipe, so even if the end is a bit corroded, I wouldn't worry about it too much, and think it needs immediate replacing while the engine is in situ and access is not so good...I'd wait unitl next time engine is out. You can post a picture of it if your that concerned, and we can have a look at it and give you our further opinion.

Cooling Sys rule No. 1: Always fill with 50% Ethylene Glycol mix (which has anti-corrosive additives, never plain water!)

Cheers
 

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Discussion Starter · #3 ·
Getting to the back of the head is not too hard. I'd have to loosen the pipe coming from the front to make sure I have enough room to have a small pipe wrench back there. The top of the pipe just looked really corroded. Very jagged edge. Since I had the heater out and was replacing all the hoses, I figured replacing a nasty pipe would be a good idea. When I bought the car, the previous owner had bypassed the heater with a hose connecting the two from the engine. The fluid in the radiator looked nice and green, but he may have just topped it off to sell it to me. based on the pipe condition, I think it was not well maintained.
 

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Not sure if you’ve actually removed it. I understand the reluctance to disturb something that like looks so bad, but if you don’t deal with it now, it’ll fail at the most inopportune time. I got mine out with some PB Blaster applied over a couple days. Then you can either clean it up and replace it or get a new one.
Being thorough pays off.
 

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Discussion Starter · #5 ·
Craig,

I agree with that. I just hope the part threaded into the head is solid enough to take the torque it will need to get it loose. I'm going to run some rust remover through the system. I'm going to try either really strong vinegar ( 30% cleaning vinegar ) or some dilution of phosphoric acid. Maybe that will help before I try taking the pipe out.
 

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To get the best results for removing the pipe, repeatedly soak, over the course of a few days, the threads with PB Blaster or other purpose specific penetrating fluid. WD40 or other oil won’t cut it.

I’d recommend you stay away from a home brew acid flush, could be dangerous, and may damage aluminum in the engine, like the water pump and thermostat housing. Better to use commercial Rad Flushes from an auto parts store.
Best of luck.
 

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Guys;

That pipe is installed with threadsealer, which has had countless thermal cycles to cook in place, so I expect soaking it with whatever solvent,you think is supergroovy will have about the same effect as not soaking it...which is to say ZERO...so IF you break it off (which I still kindof doubt as it is a heavy wall pipe, corroded end notwithstanding) when trying to loosen it while engine is installed, you will then probably need to remove the engine to get access for proper repair actions...I don't mean to rain on anybody's parade, but why would you take such a huge chance and try to remove it with marginal access, but a significant possibility of damage, and even less access for repair work if necessary? ...so the end of the pipe has some corrosion...big deal...I bet it will still outlive all of us...!

Cheers
 

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Discussion Starter · #8 ·
Ron,

With the return pipe loosened and move out of the way, access to the 90 degree pipe doesn't seem too hard. The pipe end is really corroded. There is no factory edge anymore. It's been eaten away. No flared end left. Just a ragged end of a straight pipe. I'm not so sure how reliable this will be over the short term, let alone outliving me. I have not had great luck with retail cooling system flushes.
 

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JW;

...that pipe wasn't flared or bulged to begin with...just push the hose on it a little further, and tighten the clamp and be done with it...I think you should find yourself a high-maintenance girlfriend...and she can outlive you too, because you're clearly shortening your life worrying about this...why don't you post a picture, and we can make a better informed call...maybe I'm all wrong on this...!

Cheers
 

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I'm with Ron. It's a pipe and it doesn't move. There's almost no pressure in the system. What bad thing could happen? Clean up the ragged end and use a fresh hose clamp and save yourself a sure headache.
 

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I think it’s screwed into the head, still not a small job if it breaks off. I contemplated taking mine out when I overhauled the cooling system, but it was in fine shape. Appears to be stainless steel, does have a flare on it. Maybe It’s been previously replaced with something else?
Most of the usual suspects have the part available, so maybe there is a demand for replacements.

http://irollmot.ipower.com/oscom/product_info.php?products_id=1346

A picture from John would help.
 

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Discussion Starter · #12 ·
The replacement part has a bulge at the end to help keep the hose one. If the original was the same, that part of the pipe is rusted off. I will be at my Dad's shop on Sat. I'll take a picture. Looks more like a broken off bottle from a movie that a water pipe.

Ron,

I like doing things right, if I have the opportunity. I have the opportunity. If the pipe will not thread out with reasonable force, I'll wait until I rebuild the engine. If it shears off, with easy force, it was close to failure and I'll have saved my self the trouble and expense of a tow truck.
 

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JW;

I certainly understand about "doing things right", and I agree...but there are times when a judgement call needs to be made, and one guy's "right" is another's "hack-job", and experience comes into play...I find this particularly on the German Volvoniacs Forum...those guys work to a very high standard, often replacing items with new, when the item could be rebuilt, or cleaned up, reworked or restored and easily give service for another 50 years (they must also satisfy the quite strict TUeV inspectors, which thoroughly check all cars every two years)...opposed to here, where we have no such inspection, and sometimes, repairs by previous "specialists" can be downright scary...I'm not the former either, but consider myself closer to it than the later...

Specifically, in looking at the picture of your Heater Supply Pipe, I see some combination of corrosion and deteriorated rubber from the hose on the end of that pipe...I do not see signs that it has corroded to the point of compromising the wall thickness, or having "shortened the pipe" (in which case, I'd opt for closer inspection/replacement)...my judgement call, having seen the pipe, remains unchanged: Leave it in place, clean it as good as possible (without getting debris into the pipe), replace hose, and clamp, and forget about it until next time engine is removed for service and access is good...

Cheers
 

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Hi, I don’t disagree with Ron, but it is a judgment call. One thing I noticed from the picture is that the elbow appears to be oriented in an almost vertical position. On my B20, it is oriented closer to horizontal pointing to the right side of the car, maybe about 30 degrees from horizontal. And mine appears to be original, given the thread sealer that it still apparent. This angle accommodates the preformed OEM style lower heater hose perfectly. If you are using or have straight heater hose this wouldn’t be critical.

So maybe it has been adjusted/replaced in the past?

Would be interested in Ron’s view of my angle observation.
 

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Craig;

I agree..from the factory, they are consistently angled about half way (and any I've ever seen), so your 30 Deg estimate is close to where I would expect it...
Cheers
 

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Discussion Starter · #19 ·
Craig,

Not yet. I hate having rusty bits on the car. I decided that for right NOW, I am trying to make the car road worthy and see how all the systems work. I suspect I will need to rebuild the engine since all the cylinders are even, but low, so when I do that, the pipe is coming out.
 
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