The barbarically welded on Ford Aerostar Flex Exhaust Pipe hanger will rust out and separate from it, resulting in a gaping hole in your exhaust system.

 

Good to know. Time to reinforce it with either more weld or some metal plates.

 

Shrug, this is my 2nd Aerostar where the Exhaust Flex Pipe hanger has separated from the pipe, thereby creating a tiny hole in the pipe.

On my prior Aerostar, I wrapped the hole with an empty mushroom can.

This time I am going to replace the Exhaust Flex Pipe with a new unit.

It's a PITA removing the front flange bolts. I'll probably have to cut them.

 

The problem is the stock flex pipes are cheap, and most of the replacements you can buy are also cheap. If you call Bear River converters, they can hook you up with a much better upgrade version and multiple options at that, including options for vehicles that no longer have the factory flange.

 

Khan, I'm sure you have a very good product. But it sure would be nice to tell everybody in your posts that you are the owner of Bear River converters, especially since you are no longer a site supporter. And no, I don't have a company that is in competition with you either.
I'm just sayin.

 

Actually, I already bought an super high quality flex pipe from Exhaust Direct.

The struggle now is to remove those freaking 18 year old PITA flange bolts.

 

I used to sell those. They are manufactured by a company in Canada called Flangex. I quit carrying them because

a) The flex unit itself at the time was a single braid type, which is inferior. Maybe they fixed that, look inside, if you can see the bellows inside then it is a single braid type. If you see a woven braid pattern like the outside, then it is a double braid type and is much better. The reason the single braid is that without the added protection of the inner braid, the bellows overheat and separate. They also create turbulence which will make a howling noise at certain RPMs.

b) the type of hangar they use is cheap. The problem I have seen with that style hangar is the amount of movement they allow. This causes the rubber bushing to wear out, and puts more stain on the muffler inlet and flex pipe. The ones we designed use a new stronger grommet and hangars which lock in place so that they don't allow for excessive movement.

c) When we were getting them, they did not use an Aerostar specific flange and gasket, they used a universal flange and gasket that had slots instead of holes. This style of flange will warp over time because the slots weaken it. Once the flange is no longer flat, it doesn't seal and you get an exhaust leak. The slots allow water to get in and eat the bolt from the center, which causes them to break. Ours used a laser cut flange that was specific to the Aerostar, and used the correct gasket. We also included marine grade stainless steel bolts, nuts and washers so that they could withstand exposure to saltwater and corrosion.

Ours had other benefits as well. The opening in the flange was 2 1/4" (stock) so it doesn't create turbulence as exhaust flows past, and we offered it with 2 1/4" flex as an option for higher performance on 4.0L engines. We actually sell a complete catback kit that uses a muffler I have found to be free of any flow restrictions while still being tame enough sounding that when the wife is driving around a grocery store parking lot, nothing seems out of the ordinary.

Break the flange bolts, you can't reuse them anyway. If you have access to a sawzall, just cut the head off on the side of the flange that you are replacing. These days, we only custom make the Aerostar flex assemblies because we offer different designs, including designs for those that are missing the stock flange and want to upgrade to a superior type of flange that is both easier to service and more durable and does not need any type of gasket.

 

In reply... to Khan,

a) The flex is double braided, on the outside and on the inside.

b) I don't see anything wrong with the hanger, it is extremely strong.

c) There is no slots in the flange, and the gasket fits better than Fords.

I don't have a 4.0L, and the Flex Pipe is the same diameter as the stock.

And I don't plan on reusing the flange bolts. I got new stainless steel bolts.

Thank you very mucho!!!

 

Sounds like you are set then. The problem is not with the strength of the hangers,the problem is that they ruin the grommets. Since they only support on the sides (the stock uses a u-shapped channel), and the hanger will invariably slide forward and back as the vehicle moves, it cuts through the grommet. As the grommet deteriorates, the whole thing moves even more which transfers a lot of the strain to the neck of the muffler and causes the muffler to break.

Glad to hear they fixed the flex, they probably got too many complaints and decided to fix that.

Glad to hear they started using the right flange and gasket, they probably got too many complaints about that too.

 

They have two products for the Aerostar Exhaust Flex Pipes.

One is like the one I purchased, the other is u-shaped hanger.

I was impressed with the thickness of the pipe. Better than Ford.

 

Thickness of the pipe means nothing, I have never seen a stock pipe break. The flex itself if its a double braid is better than OEM, but the stock pipe is stainless steel, the replacement uses aluminized mild steel because its cheaper. Aluminized steel will rust away from the inside out. Ours uses aluminized too, stainless steel is just plain too expensive. The OEM pretty much better than anything you are likely to fin aftermarket for an Aerostar. If you were to replace just the flex itself rather than the whole unit, you get the best of both worlds, OEM stainless pipe with a better flex.

 

Here is photo of the "stock" pipe.

Definitively NOT Stainless Steel.

This Exhaust Flex Pipe is Superior.

 

That is stainless steel. If it wasn't stainless, it would have been completely rusted gone 5-7 years ago. Your new unit will probably last 3-5 years, 7 tops if you are in a desert climate. The stock unit is made from T409 stainless steel, which will oxidize and turn brown and pit as exposed to salt and heat, but does not rust per se. It leasts 12-20+ years depending on use and climate. Ford began using it in the early to mid 80's and there are still cars from that era with the stock exhaust systems. The stock flange and bolts are not made from stainless however, just the pipe. If T409 is welded with mild wire, the weld will rot out.

The new unit is most definitely not superior to OEM. Your rusted through there because it was welded on, weakening the pipe.

 

Thanks for the info Khan.

One thing I noticed about the EXD Exhaust Flex Pipe is that the braided section is about half the length of the Ford stock part.

I managed to remove the flange bolts using a propane torch. They broke off.

However, I was unable to separate the rear pipe section of the Flex Pipe which is inserted into the muffler because the muffler clamp squashed the pipes together.

I gave up for the time being, and then patched the pipe hole with a exhaust repair kit.

 

Yeah, saddle clamps are terrible that way. I sell clamps, but not saddle clamps. The type I would recommend is the Torctite clamps, they form a perfect and strong joint without damaging the pipe. They cost a lot more than a saddle clamp, but the who idea behind a clamp is that you can take it apart later, otherwise you might as well just weld it. Saddle clamps don't seal either, they pinch the pipe so it leaks to either side of the clamp.

To dismantle a saddle clamp joint, there are only too options, The first only works if you get lucky, but basically if it not squashed too badly, it is possible to keep wiggling and twisting until the joint comes apart. The second is to use an oxyacetylene torch to carefully split the out pipe without damaging the inner one, and then pry it off. Since your outer pipe will be the muffler, this obviously ruins the neck of the muffler, and is not a good option either. If you are careful it is possible to do it without ruining the neck too badly.

Shorter flex sections can be a bad thing. A longer flex can withstand more stress, since it distributes stress over a larger area, preventing it from forming a break. However the stock flex is old and is not the best that Ford could have used. Its not terrible. The biggest problem with the stock flex is actually twisting stresses. The flex can handle expansion and contraction, and flexing back and forth just fine, but when it gets twisted it puts stress it was never designed to handle and that weakens the flex over time. A longer flex can handle it better though.