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View Full Version : PCV Tube substitutes?



BlueTech
10-04-2019, 09:29 PM
My PCV Valve is fouled. Easy to replace? Nope. Plenty of posts on how difficult these are to get out without breaking the lower tube, especially after being in a hot engine for 33 years. All true. Applied a bit of light weight oil and allowed it to seep in between the PCV Valve and tube for a long while. Then made sure to get the engine nice and hot to soften the tube before attempting to remove the valve, but no joy. The PCV Valve spins nicely in the tube, but the lower barb has bitten into the tube and it will not budge upwards. I can already see that the top of the tube is cracked, so it too now needs to be replaced.

Considering that the lower tube is beyond obsolete, does anyone have a suggestion for a substitute tube/hose that has worked well?

I would also appreciate advice how swap out the dang tube once I find something that will work. It is not visible from the top or sides. I have not yet raised the car and removed the splash shield, so maybe it is not as bad as I fear.

Thanks,
Blue

Dr_Snooz
10-05-2019, 06:02 PM
Try this one: https://www.3geez.com/forum/3geez-accords/139715-lets-talk-about-black-box-pcv-intake-hose-one-more-time.html

BlueTech
10-08-2019, 12:58 PM
Excellent. Thanks! I had not yet discovered that post. That solution looks workable to replace the diamond-hard lower tube in which the PCV valve sits. I was planning on getting that piece out and looking for a similar shaped PCV Tube that I can cut to size. I may still go that route, but have no idea what the ID is for the box side. At least there is a solid backup option if that is not fruitful. If I do find a PCV Hose that works, I'll update this thread with the part number(s). Whichever solution happens, it needs look OEM enough that the smog guy never raises an eyebrow.

The good news is that I did manage to get the super-stuck PCV Valve out easily. It was definitely gummed up and fouled. In hindsight, I really wish I had removed it this way first... Slide hammer attached to vice grips ;). It took the valve out very nicely without muss or fuss in less than a minute, and may not have split the stupid tube. Too bad I had already damaged the tube trying to remove it the ol' fashioned way.

http://i1337.photobucket.com/albums/o672/junkmail9/SlideHammerViseGrip_med_zpskkpfvzgq.jpg
My special Vice Grip Slide Hammer. Extremely handy when you need it. Craft created for a prior unique situation

Now to get to the black box and remove it... I assume it can be easily reached from under the car once the splash shield is removed?

ETA - I had a little time last night, put the car up and looked around. Is there really only one bolt that holds the black box? If so, this may not be too bad if the oil filter is removed. Then I might actually be able to see the upper hose.

Dr_Snooz
10-09-2019, 06:10 PM
I assume it can be easily reached from under the car once the splash shield is removed?

:rofl: he said "easily" :rofl:

BlueTech
10-10-2019, 02:01 PM
:rofl: he said "easily" :rofl:
Heh-Heh-Heh... Heh-heh-heh... Yeah. I'm an optimist.:rolleyes:

How about, "easily" as compared to replacing a couple of the engine mounts on this thing. Specifically the bolt buried inside the bracket on the underside of the front mount...

InAccordance
10-11-2019, 03:21 PM
Take the intake off and you'll have all the access to the black box you could ever want lol

BlueTech
10-11-2019, 04:05 PM
Take the intake off and you'll have all the access to the black box you could ever want lol

LOL. Yep. True enough. Still seems easier to go from underneath. Then again, the current carburetor is coming off soon. The linkage is beyond sticky and will not clean up, and the AC boost dashpot is dead. Amazingly, you can still get a shiny rebuilt carb for this beauty - with a rebuilt AC boost dashpot already installed! This was a pleasant surprise.

Either way, the PCV problem needs to wait a bit. Pesky other cars need some TLC this weekend.

I did manage to find a NOS OEM breather tube that should be here mid-next week, and the O-Ring for the black box was easy to find at McMaster for 1/25th the cost of the OEM. Well... it's the same price as the OEM but I get 25 of them, so I can do this 25 more times :rofl:

But seriously, to take off the black box - what's the trick? Even with the single bolt removed the black box does not want to budge. Are there other bolts bolt somewhere? Do I need to remove the dang exhaust bracket as well? The exploded diagram does not show what else is attached in other areas, nor can I find this in the manuals.

g.frost
10-17-2019, 03:07 PM
I don't know how badly cracked your PCV tube is... and always putting the big jobs off if possible,,,, I got the best all metal PCV valve, carefully cleaned the remains of the tube and smeared the cracks up with black high temp RTV... After that dried I glued the PCV valve in place with the same. :omg: That was many years ago and has always passed CA smog inspections. They never looked at it twice.

Alas, my old Jimmy is gone now; traded for a cord of hard wood last fall. Too many old cars here, I had to let one go.

BlueTech
10-17-2019, 04:24 PM
I don't know how badly cracked your PCV tube is... and always putting the big jobs off if possible,,,, I got the best all metal PCV valve, carefully cleaned the remains of the tube and smeared the cracks up with black high temp RTV... After that dried I glued the PCV valve in place with the same. :omg: That was many years ago and has always passed CA smog inspections. They never looked at it twice.
I actually do not know how deep the damage goes. After getting the PCV valve out, it looked like the top of the tube was in tact. It was in fact a perfect "slice" just sitting right on the top of the tube below, and I can see a crack going down. How far is unknown. I like your idea and may need to do it that way. I did (maybe) find a rare NOS upper tube online this week and should know by next week if it actually exists. If it doesn't, then black RTV it will need to be.

In the mean time, I can tell that the remaining parts of the upper tube (cracked or not) is full of gunk. The old (metal :)) PCV valve was caked up with a micro-ton of grimy guck (and was the reason that the valve wouldn't function properly). After re-reading the thread that Dr. Snooz linked, it appears that there are two bolts holding the black box on, not one like the exploded diagrams indicate. If so, I will be taking it off along with the cracked tube, cleaning them up inside. There is no longer anything holding that upper tube into the manifold, so it should just drop along with the box... (Notice I did not say "easily drop"... :rofl: fingers crossed).

InAccordance
10-17-2019, 04:30 PM
It will, there's an o ring to seal it to the block but after the bolts, that's it

g.frost
10-17-2019, 06:33 PM
Yeah, mine was relatively clean and still functioning at 125K+ miles (original PCV, approx., no longer have my service records, gave them to the new owner.) That engine was still tight, smooth, and no significant blow by or burn oil at 177K miles. I thought about making the seal with the RTV alone, not 'permanently' gluing the PCV valve in. I didn't want to take the chance it would leak and ingest dirt though. If you are already committed to get the box out, do it right.

Dr_Snooz
10-17-2019, 07:15 PM
and the O-Ring for the black box was easy to find at McMaster for 1/25th the cost of the OEM. Well... it's the same price as the OEM but I get 25 of them, so I can do this 25 more times :rofl:


You're gonna be pretty bummed when you learn that you could have used any old oring from your cheap Harbor Freight kit...



But seriously, to take off the black box - what's the trick? Even with the single bolt removed the black box does not want to budge. Are there other bolts bolt somewhere? Do I need to remove the dang exhaust bracket as well? The exploded diagram does not show what else is attached in other areas, nor can I find this in the manuals.

Yes. There's another bolt and l do believe you have to remove the bracket. Or at least it will make it easier.

InAccordance
10-18-2019, 12:28 AM
Yeah, mine was relatively clean and still functioning at 125K+ miles (original PCV, approx., no longer have my service records, gave them to the new owner.) That engine was still tight, smooth, and no significant blow by or burn oil at 177K miles. I thought about making the seal with the RTV alone, not 'permanently' gluing the PCV valve in. I didn't want to take the chance it would leak and ingest dirt though. If you are already committed to get the box out, do it right.

ha! I have so much blow-by it's funny. Most of it is due to bad valve guides dripping oil into the chambers though. but... almost 300k miles will do that.

InAccordance
10-18-2019, 12:30 AM
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You're gonna be pretty bummed when you learn that you could have used any old oring from your cheap Harbor Freight kit...

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Yes. There's another bolt and l do believe you have to remove the bracket. Or at least it will make it easier.

Do the FI cars have the support brackets? honestly cant remember and thought that was a carb thing cause the intake hung off the engine further.

Dr_Snooz
10-18-2019, 08:30 PM
Nah, there's a big bracket back there. Right in the way of the black box.