Fixing Leaky Intake Manifold (Part 2)

[bostonbronconut]

The DOAZ part came in three versions: A, B, C. B & C were made at an angle and for later models. The crankcase breather looks like it could fit inside the air cleaner housing but why would two filters be needed inside the air cleaner? Either way, if I can find a way to connect the air cleaner to the charcoal canister, I'm happy.

 

[Wild horse 75]

The breather filter isn’t a second filter for crankcase air. The filter attaches to the housing outside the air filter for the carb. So it’s the only filter for the crankcase.

 

[DirtDonk]

OK, let’s talk about the two different systems here.
The central mounted elbow and the valve cover elbow are for the PCV system. They are behind the main air filter element, so only clean air is sucked into the engine.
The pictured EVAP filter element sits in the air cleaner housing, but outside of the filtered air area. It is not to filter air coming into the engine, but rather to keep bugs, rats, debris, maybe even excess moisture, that might get into the air cleaner housing, from getting down the line into the charcoal canister.
It’s also possible that it might slow down the flow of liquid gas that might have gotten into the charcoal canister, from pooling inside the air cleaner. Perhaps creating a fire hazard.
That’s just a SWAG on my part, but I’m pretty sure the first explanation is legit.

 

[bostonbronconut]

I went to AutoZone and tested out three different crankcase breathers and went with the Duralast Breather Filter BF3303DL, which fit the air assembly the best and the nipple is the same diameter as the Dorman Vapor Canister, which I also bought. Although the filter comes with a retaining clip, I couldn't use it because it isn't an exact fit to the air cleaner assembly so I used two o-rings for a secure fit. This setup does not require the DOAZ-9D692 part that is no longer readily available.

Back To Fixing Oil Leaks
I reassembled the intake manifold and started the Bronco yesterday for a test drive. I've put some white paper underneath the engine to learn if the oil leak has been resolved. Thus far, I've seen two leaks, which I've highlighted in the attached message.

Purple rectangle: The oil stain looks cleaner and is a similar color to the new oil I recently added. It seems like it might be coming from the new oil filter so I tightened it a little more with an oil filter wrench.

Red rectangle: This oil stain is a darker color. I found dark oil on the transmission (see: transmission-view-dark-oil), which looks to be the point where the oil drops from but not necessarily the source of the leak. I've included another photo from a different angle after I have wiped some of the oil off of the transmission. I am curious what you think of these initial photos; I can provide more photos if that is helpful.

 

[Revelation]

Looks like the leak in the rear could be
1. Residual from the intake leak in the Bellhousing
2. Rear Main seal
Leak in the front could be
1. Residual from the vent leak
2. Valve Cover leak
3. if not Motor oil could be PS fluid.

 

[tirewater]

Re: PCV—I read that a blocked/bad valve could result in increased pressure and oil being pulled into the engine. Some oil was in a little hole at the end of the block and dropped inside the engine, but not a large amount. That being said, the PCV does rattle as you mentioned in your earlier message so maybe that isn't the issue. But, since it is a $5 part, I don't mind swapping it out and just having ease of mind.

Re: Housing - I plan to get all of that assembled correctly so I am no longer pulling in dirty air. I am also going to get a charcoal canister as well. I've found a used one online (https://www.northeastclassicfordparts.com/product/fuel-vapor-charcoal-canister-1976-1977-bronco/) at a decent price. That being said, CJ's and some chains sell new canisters; are there any OEM/AMs you'd recommend?

Re: Vaccum Tree—I put new vacuum caps on a few years ago; it doesn't seem like they are leaking yet, but similarly to the PCV, they are not too expensive and easy to replace.

Re: Valve Covers - I was considering switching the valve covers from one side to the other because I have a lot of hoses on the passenger side, and it would help with organization and clutter. I hope to remove the valve covers within the next 48 hours and will provide many photos when done.

Re: Broken Bolt - One thing I haven't mentioned is that one of the manifold bolts broke off (green circle). It looks like a clean break, so I was going to use a bolt extractor to get it out, but I figured I would mention it if you recommend another method.

The hole you have circled in purple uses a welch plug. I can't tell if there's one in there are not from your picture. I grabbed a photo from from another website. I don't know the ramifications for not plugging the hole, but pressurized oil is pumped through it. It could be a source of a leak.

 

[bostonbronconut]

Looks like the leak in the rear could be
1. Residual from the intake leak in the Bellhousing
2. Rear Main seal
Leak in the front could be
1. Residual from the vent leak
2. Valve Cover leak
3. if not Motor oil could be PS fluid.

I'm hoping it is residual. It is unlikely a Valve Cover leak as I just replaced the valve cover gaskets during this whole process but I will certainly keep an eye on it.

 

[bostonbronconut]

The hole you have circled in purple uses a welch plug. I can't tell if there's one in there are not from your picture. I grabbed a photo from from another website. I don't know the ramifications for not plugging the hole, but pressurized oil is pumped through it. It could be a source of a leak.

Thus far, my latest attempt at sealing the intake manifold looks to be working. I just checked the oil well behind that hole, and it is dry at the moment. When I had the intake manifold off, I cleaned up that hole and it seemed closed off but there was some oil in it. After looking at some photos I took during the process, I'm starting to think that the hole was not plugged.

 

[tirewater]

Thus far, my latest attempt at sealing the intake manifold looks to be working. I just checked the oil well behind that hole, and it is dry at the moment. When I had the intake manifold off, I cleaned up that hole and it seemed closed off but there was some oil in it. After looking at some photos I took during the process, I'm starting to think that the hole was not plugged.

It's tough to see, but since it looks like oil pooling in the hole, it probably is plugged.