T

trib

Well Known Member
Just purchased a heater/radiator hose from advance auto to use as the breather tube on my O360. If any of you are in need of one, the stock number at advance is 80416. This is a Drive-Rite hose with 0308-49602 stamped on it if you are searching at another store than advance. It fits the accessory fitting perfectly and has the 90 degree bend molded in. It's also plenty long. Trim to fit was 1/2" off the 90 bend end and then 16" off the long straight end. $14.99 was the going price.

Might save you a little time searching!:)
 
Heater hose

trib said:
Just purchased a heater/radiator hose from advance auto to use as the breather tube on my O360. If any of you are in need of one, the stock number at advance is 80416. This is a Drive-Rite hose with 0308-49602 stamped on it if you are searching at another store than advance. It fits the accessory fitting perfectly and has the 90 degree bend molded in. It's also plenty long. Trim to fit was 1/2" off the 90 bend end and then 16" off the long straight end. $14.99 was the going price.

Might save you a little time searching!:)
Click to expand...

A comment from an old "car guy", heater/radiator hose isn't a good idea for breathers. The rubber isn't designed to carry oil or oil mist and will swell and soften with time. Fuel hose is resistant to hydrocarbons (duh!) and comes in all sorts of sizes and configurations.

John Clark
RV8 N18U "Sunshine"
KSBA
 
John Clark said:
A comment from an old "car guy", heater/radiator hose isn't a good idea for breathers. The rubber isn't designed to carry oil or oil mist and will swell and soften with time.
Click to expand...

Yep, found that out the hard way. After around 100 hours, the heater hose I used for breather hose had turned to goo. I knew going in that it wasn't the right material, but I didn't expect it to happen so soon. It was maybe 8 months that it was in there before I ripped it out and replaced with proper hose.

Heinrich Gerhardt
RV-6, flying
 
CRS

It's been a couple of years since I did the FWF on my 9A, but I'm pretty sure Van's breather hose had a NAPA sticker on it.
 
My understanding was the Van's hose was just a NAPA radiator hose, so that's what I went in looking for. Is the hose something different? Is fuel hose available that large? The ID is 3/4".
 
Yes...

trib said:
My understanding was the Van's hose was just a NAPA radiator hose, so that's what I went in looking for. Is the hose something different? Is fuel hose available that large? The ID is 3/4".
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Yes, breather hose is different from radiator hose and is available in 3/4 and bigger. Most reputable parts stores will have it in bulk. Just make sure that the person at the counter understands what you want.

John Clark
RV8 N18U "Sunshine"
KSBA
 
That looks just like the one I got from Van's, I checked the Advanced website. By the way, the NAPA part number is: NBH 9820.
 
It'll work for awhile, but eventually it will soften up, and then you have oil mist all over your engine bay. I suggest using Mil 6000 spec hose and deal with not having the 90? bend molded.
 
Since it's installed at this point (and looks good, I might add), I'll keep the replacements in mind when it eventually softens. Since it'll be the same effort to replace later as now, I might as well get the use from the material I already paid for:D
 
Silicone heater hose

....is the best I have found. Available at NAPA and other parts stores. Very tough, and oil and heat resistant. 3/4" stuff is about 5 bucks a foot. Not cheap, and pretty hefty in outside diameter, but is a permanent solution. We pro auto techs use it all the time in critical, hidden under the intake applications, and for oil breather applications whenever possible. Green in color. Takes a bend well. ACS has silicone hose, but the sample I saw was not reinforced, and that stuff likes to split around the clamp line. A big No-no in auto applications, so I decided against it when I built my plane.
NAPA stuff is Flexfab 5521-075 for the 3/4". 5/8" and 1/2" ID sizes are also readily available.

Hope this helps
Chris
 
Automotive Breather hose can be subjected to very high vacuum (PCV systems) and that is why it is thicker and harder than rad/heater hose. Just ask the customer that came in with no brakes after using a piece of heater hose from the manifold to the brake booster. As mentioned it is compatible with oil and oil mists.

Bob Parry
 
Failure modes not noted

HEATER hose is typically EPDM or some derivative. Alcohol, acid/base, steam resistant. NOT oil/hydrocarbon resistant, as other posters have noted. When EPDM sees hydrocarbons, the material breaks down and softens. In a racing app, strictly a breather application, just like we're talking about here, we saw the inner liner separated from the reinforcement, thereby blocking the tube, which is a recipe to blow out the nose seal. The other failure mode is loss of grip on it's retaining lip, resulting in the loss of the tube, which will smolder nicely on hot exhaust manifolds.

Breather hose is oil-hydrocarbon resistant but not alcohol resistant, and some have steam issues. It doesn't cost anymore, it is just as available. Silicone is a good alternative, as is anything with a teflon internal liner.

It's Experimental Aviation, and each of us is left to make our own judgments, but seems like replacing a piece of $5 hose with the right stuff is an easy risk management decision.

But that's just me. Rick 90432
 
Is Vans breather hose suitable

I note on this thread that some people are suggesting that auto coolant hose may not be suitable for the oil breather line....that they may turn to "goo" when subjected to oil.

The hose that Vans supplied me (right angle hose) in their FWF kit is NAPA #9816 which I presume may be an auto coolant hose. Is it possible that this hose will soften and disintegrate over time.

Has anybody with serious hours up had problems with the rubber right angle breather hose supplied by Vans.
 
Captain Avgas said:
Has anybody with serious hours up had problems with the rubber right angle breather hose supplied by Vans.
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Closing in on 1100 hours and 4.5 years in the air Bob, and I haven't noticed any problem with the Van's hose. I keep my engine compartment really oil-free, so I probably wouldn't see a problem on the outside of the hose if it is dissolving from the inside...

One data point.

Paul
 
Ironflight said:
Closing in on 1100 hours and 4.5 years in the air Bob, and I haven't noticed any problem with the Van's hose. I keep my engine compartment really oil-free, so I probably wouldn't see a problem on the outside of the hose if it is dissolving from the inside...

One data point.

Paul
Click to expand...

Check the inside of the hose, Paul. I have no experience using that exact hose in an RV, but I have plenty of experience with coolant hoses (which, based on the NAPA part number, is what that hose is intended for) used in auto applications as breather hose. Mostly from a lifetime of working on older cars where someone else (or me, before I knew better) substituted coolant hose in a breather application. Eventually the hoses disintegrate internally. If your engine is exceptionally miserly about oil consumption and has low blow-by, it could take a while. A tired engine will likely trash the hose more quickly. Goo describes the result pretty well.

Coolant hoses are lined with EPDM (ethylene propylene diene monomer if you really want to know) which is exceptionally good at resisting water and water-soluble chemicals, nossa good at withstanding petroleum products. It's the same stuff you need for brake system o-rings if you convert to DOT 4 brake fluid.

Maybe more than most people want to know, and practically speaking if you keep an eye on the hose it probably doesn't matter. But if the goo let go and clogged the vent tube, it could get messy.
 
I got 700+ hours out of a coolant hose on my breather before it started to turn to goo. Your mileage may vary. If I had known better, I would have used the right stuff to start with.
 
Funny mishap with wrong hose

30 years ago, I had a job pumping gas at the local full-service station. A guy rolls up in some spiffy little British convertible and tells me to fill er up. I insert the pump nozzle firmly into the filler just above the rear bumper and give it a good push downward to wedge it in place. A minute or so later as I'm washing the guy's windshield, I hear him yelling "shut it off!!". I do so and can see gas running out under the rear of the car. The guy opens the trunk to reveal all his dry-cleaning submerged under several inches of fuel. Seems the fill hose, which runs right through the trunk interior, had ripped wide open when I inserted the pump. My boss came over and pulled out the ripped (radiator) hose and immediately pointed out the writing on it that said "not for use with fuel".
I'm sure hoses are tougher nowadays, but I can tell you that that particular hose had turned to spongy goo on the inside.
 
szicree said:
30 years ago, I had a job pumping gas at the local full-service station. A guy rolls up in some spiffy little British convertible and tells me to fill er up. I insert the pump nozzle firmly into the filler just above the rear bumper and give it a good push downward to wedge it in place. A minute or so later as I'm washing the guy's windshield, I hear him yelling "shut it off!!". I do so and can see gas running out under the rear of the car. The guy opens the trunk to reveal all his dry-cleaning submerged under several inches of fuel. Seems the fill hose, which runs right through the trunk interior, had ripped wide open when I inserted the pump. My boss came over and pulled out the ripped (radiator) hose and immediately pointed out the writing on it that said "not for use with fuel".
I'm sure hoses are tougher nowadays, but I can tell you that that particular hose had turned to spongy goo on the inside.
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Great story! Working at a "service station" (calling it a gas station was an invitation for an instant chewing-out by my boss) 35 years ago in SoCal was where I first encountered the gooey hoses I mentioned. Hoses aren't any tougher now. They were EPDM in those days, nothing has changed- still the most economical choice for hot water or glycol ether brake fluid. I would have never had a clue about that but for career choices that required me to learn about rubber (elastomer) compounds.

As for the Vans crankcase breather, I discovered today that the pipe supplied in the firewall forward kit is going to require a lot of massaging to fit my -7 firewall, whether I used the supplied NAPA coolant hose or something else.
 
All the right stuff

Easy to find at Napa.-- CS112305 Z200 Made by Gates
ip9u3a.jpg
 
Hmmm...

That would not fit my engine, the breather tube on mine is over an inch in diameter.

Hans
 
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