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94 3.4 DOHC heater pipe quick disconnect O-Ring


GnatGoSplat

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Anyone happen to know the size, or a part number, or anything on the O-ring for the 3.4 DOHC quick-disconnect heater pipe? The one on the lower intake manifold. It's a 94, though I'd guess it's the same O-ring for any years that used a quick-disconnect there.

 

The car is my wife's DD so I don't want to take it apart and come to find I can't find the O-ring anywhere.

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Yep, that's what I'm talking about. My fitting is still okay, but the O-ring was pretty worn though. There is an O-ring at the end of the black pipe part. It's not a bad leak yet, just dribbles out and drips onto the exhaust manifold. Seems to be getting a little worse as well. It was enough to top off the reservoir once every 2-weeks, now it's about once a week. Would be nice to not have to top it off at all.

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Yeah, I figured I'll probably have to pull it off and go hunting for the closest size. Just kind of worried I'll get there and they won't have anything that's even close, and then I'll have to put it back together with the old O-ring that's even more worn from pulling it out again and go through that annoying bleed procedure. Hopefully they'll have something.

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I've got the dealer parts catalog, the O-ring comes with the whole fitting.

 

UPDATE: Emailed Dorman thinking it'd be a long shot. They gave me these specs: 15.54mm ID, 20.78mm OD.

Edited by GnatGoSplat
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Thanks, but no thanks! That HNBR stuff must be worth more than its weight in gold.

Assuming those measurements are correct, I think this is really close and much more reasonable:

http://www.oreillyauto.com/site/c/detail/NAT0/114/N0243.oap?ck=Search_N0243_-1_4084&pt=N0243&ppt=C0142

 

Not sure those measurements I got from Dorman are correct or not though. My memory of the O-ring is it was smaller than that, but my memory is pretty hazy. Well, I should be able to find one locally which is the important thing so I'll probably pull it off first so I can compare it to what they've got.

 

I also need that stupid plastic clip that is Dorman p/n 800-405. The pipe being bolted to a bracket is the only thing keeping it attached.

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  • 2 weeks later...

Got this job done this morning. Not real confident about it though. National 114 is the right O-ring and that part is fine, but there are other plastic bits in that fitting and one of them crumbled when I tried to clean out the fitting with a rag. There is one plastic piece that goes in before the O-ring, then the O-ring itself, then a brown plastic ring that goes in after the O-ring, then lastly the 800-405 clip that fits on the pipe. The very first plastic piece crumbled into pieces. I think it keeps the O-ring from slipping off the front of the pipe. I ended up putting the clip on the pipe, then the brown ring, then the O-ring, and putting two of the larger broken pieces back in the metal fitting, then pushing the pipe in place. Hopefully those 2 broken pieces will be enough to prevent the O-ring from vibrating out of place and slipping off the pipe. So far no apparent leaks in that area, though there is still some steam coming up when I stop the car on the driveway. Probably just spillage burning off (I hope). It quits when the car has been level a few minutes.

 

Another annoyance that really bummed me out, I noticed a small puddle forming under the front pass side of the car. Looks like coolant dripping off that plastic airdam piece and I see a little bit coming from the metal core support. I'd guess there's maybe a small leak on the plastic radiator tank. Ugh, I replaced it just 4yrs ago, do these things not last longer than that? I fix one thing and immediately another problem pops up! I think the car hates me and I hate it right back.

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Probably should have, but I didn't realize the plastic insert thing was bad till I already bought the O-ring and clip and came home and didn't really want to make another trip to O'Reilly. Seems like what I did will work (no leaks so far), so not sure I should mess with it any more. I have really bad luck with anything I do on this car and I could see that metal fitting stripping the threads out of the intake manifold or something really awful like that. I didn't want to risk it. I've never had a job on this car end up being straight-forward. There is always complications.

 

Saw this review on the replacement part:

It would be easier to install if they left it up to the installer to apply the sealer. I used some liquid Teflon based sealer, but their

solid pre-installed sealer was blocking the threads. Otherwise, it is a very well made part. If your vehicle is very old, plan on the original one snapping off when you try to remove it. I had to cut the old threads out and use a tap to clean out the threads.

 

I can almost guarantee that would totally happen to me. Thinking I won't mess with it unless it turns out I have to.

Edited by GnatGoSplat
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ive done it several times, after a few snapps, you can hit it with a mini sawzall fromt he id outward...almost cutting through in 3 places, then a screwdriver and a hammer to snap em in and you can take it out easily.

 

i found a better way....get the dorman/help part )like 8$ iirc) and you use a pic to take the entry retainer, Oring and back spacer out (this back spacer may not come out of your OE fitting.

 

a few minutes later after some use of sil glyde, your set to snap it together and check for leaks

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Thanks for the suggestions. Yeah, if it were to bust off, sounds like it would become a frustrating all-day project.

 

So you're suggesting to gut the Dorman part and put its innards into the OE part? Sounds like that would work. I think what you describe as the back spacer is the part that crumbled apart on my OE fitting so it definitely came out. In hindsight, I shouldn't have touched it. Probably wouldn't have crumbled had I left it alone.

 

So far seems like it's not leaking (that I can see, anyway), but I'll keep an eye on it.

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Just had a random thought. That plastic crap that crumbled on me... that was a flow restrictor, wasn't it?

Damn, I think I need to replace the damn fitting after all. That is, assuming it isn't too late and I haven't already blown a leak in the heater core.

Anyone got torque specs on it? I can't find anything in the service manual that even mentions it.

Edited by GnatGoSplat
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Bought a new fitting and replaced it. There is definitely is a restrictor in it, unfortunately it's still made of plastic in the Dorman replacement, part #800-401. Fitting size is hex 27mm (1-1/16") and I didn't have a socket for it, so borrowed a set from O'Reilly. Unfortunately, it was a deep socket which is not good because there wasn't enough clearance for a 1/2" drive ratchet under the fuel lines. I'd recommend a regular socket. I made it work, but only thing I had with a head small enough was an old beam torque wrench. I had to inch out the old fitting and inch on the new one. The old fitting was also steel so it didn't break, thankfully. Very painful process of moving wrench 15-degrees, remove wrench, remove socket, rotate socket, replace, and repeat. I didn't make note of how far in the old one was threaded, but wish I did. I couldn't get the new one in all the way. I didn't remember anything in the hole that would stop it from turning and the threads in the manifold went pretty deep, but the fitting stopped turning with about 3/16" of threads showing. I guess maybe the pre-applied sealant plugging the threads? At first I was worried about not getting it in far enough, then I worried about over-tightening (took ALL my strength to get it in as far as I did), started to worry about either busting it off or cracking the manifold, so I called it done and put it all back together and seems fine with no leaks. Took nearly 2-hours. I have a knack for making simple jobs more annoying and take longer than necessary.

 

There's definitely less pressure on the heater line bleeder than before, glad I changed it before blowing the heater core. In hindsight, probably would have been a lot less trouble to just make my own restrictor out of some high-temp plastic with a drill and a dremel. Or splice an inline restrictor into the heater hose.

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It's a black piece of plastic shaped like a cap about 5/8" diameter with about a 1/4" diameter hole in the middle. Not sure about the original one since mine fell apart, but the Dorman one looked to be 2 pieces. It has a flat piece with a 1/4" hole in the middle that for some reason has a tiny plastic bar going across the hole, and the part that holds it in is like the 5/8" cap I described with about a 3/8" hole. I feel like I totally could have easily whipped something up with a drill and Dremel. Maybe even a 5/8" OD/1/4" ID washer may have worked. Don't think it could have gone anywhere with the pipe in place.

 

Oh, found a good pic of the restrictor in the Dorman part @3:09 in this video.

Looks like he has about as many threads showing as I do, so I guess it's in far enough. He said he torqued it properly, I couldn't find any torque specs. Probably over-torqued it by far, probably put over 100ft-lbs into it. Hope nothing cracks.

Edited by GnatGoSplat
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if yours came out and was steel its already been replaced, ive replaced at least 3-4 dozen over the years...th eoem are pot metal and snap off if you breath on em wrong.

 

the restrictor isnt a problem, shove a cheap 1/4" drive 9/16ths hex socket into the rubber hose at the other end of that line and youve made a new restrictor.

 

most of the time i just replace the outter guide ring and the Oring, i never touch the back ring/restrictor.

 

glad you got it fixed

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