Restoring Flexibility to rubber hoses
 

Many people wipe down their rubber hoses under the hood when cleaning... I rarely do it because I dont want to wipe away whatever keeps them flexible... but sometimes I have to get that grime off...
so what can I use to restore the flexibility to these rubber hoses (to avoid future cracking)... I want something that isnt flammable, and doesnt smell bad. (It being non-flammable is for obvious reasons, and it not smelling badly is so that I dont smell it in the car when I have my vents open).

The deterioration of rubber and plastic is a chemical reaction that takes place over time and for the most part can not be reversed. If the hoses are already hard, it would be best to replace them. Any product that will soften hard rubber is probably chemically attacking the rubber, hastening the deterioration.

Oil and road grime (and heat) will accelerate the deterioration, so it is a good idea to clean the hoses and protect them as much as possible with a product like 303. See the Wash and Wax forum.

I haven't found the magical solution for this application yet. It actually ends up being a double-edged sword. By that I mean is that you can apply a preservative to the hoses that make them soft/pliable and delays the inevitable dry-rotting, but then the applied solution becomes a dirt magnet. What's a body to do, you ask? The answer is to use products that the motocross racers use. These products clean very thoroughly without being corrosive to all the electrical connectors under the hood. Also, if you select these chemicals carefully, you can find the ones that won't harm our "S". Hint: A company called Dirt Squirt is well known in the motocross community and makes some outstanding cleaning products that won't harm our machines. Also, you can mail-order these products via Bobscyclesupply.com at a much discounted price over retail. Being a motocrosser myself in an expensive sport, I buy ALL my stuff from Bob's. Check out Bob's selection of Pro Honda chemicals. I especially like Honda's Pro Cleaner and Polish aersol. It works very well on our underhood hoses. It also is excellent for the interior dash and other vinvyls. It has an aroma like nothing else. Smells like...newness.

Rubber engine bay hoses that carry fluid will also eventually deteriorate from the INSIDE. This can take years. Even those that are never cleaned or treated on the outside will last for many years. Doing so would not extend the life of a typical hose beyond when you should be changing them out anyway. Unless you spilled acid or some other corrosive substance on them, you are worried about nothing.
Engine bay hoses, like performance tires are cleaned for looks. They'll wear out on their own regardless of if they look pretty or not.

Xviper is exactly correct. I should have stated that my recommendation was strictly based on outward appearance maintenance only. Hoses should be a part of normal replacement maintenance items....just like belts, spark plugs, fuel filters, oxygen sensors....etc.

I should have mentioned this before, but since the original poster seemed more concerned about "preserving" the hoses, I didn't address the appearance part of his question.
Believe it or not, when I clean my engine bay (and I don't do this very often since I'm not that anal about how clean it looks), I hook up to my hot water tap with a garden hose and nozzle. I hose down the engine bay to get the big stuff off, then I liberally spray Windex (yup, WINDEX) all over the engine bay (do this with a cool engine, of course), then hose it off with hot water. You would be amazed at how well this works. The Windex also leaves a bit of a coating on everything such that the water dries relatively spot free. If you are really obsessed, you can blow all the big water out with compressed air. Me? I just go for a drive and the engine heat dries it off. For the really greasy spots (if you have any minor oil seapage), use an engine de-greaser like Gunk, wipe it with a rag and hose down with HOT water. To stay on topic here, the rubber hoses come out looking dark, clean and shiny.

Xviper; I bought a brand spanking new '89 Acura Integra and had ALL the scheduled maintenance done by the dealer. The car ran perfectly utntil the dealer washed the engine bay as part of their 'courtesy' service. Right away, the engine would stall intermittently. Lesson learned? Must be very careful about where water is directed under the hood. Apparently, water/soap/pressure fouled at least one of the sensor connector pins and sent erroneous info to the ECU. Since it was an OBDI system, it never threw a CEL. It didn't recognize that there was a problem. As time goes by, repeated underhood washing causes these connectors to corrode and lose connective integrity.

Dealers use high pressure washers. We can't take what they do as an example of the "right thing" to do. :drunk: I'm using a garden hose on a wide stream, especially around wiring connections. The connectors in an S2000 engine bay is pretty water tight. I know of several of us who wash the engine in this way and never has there been a problem. One does have to use a bit of common sense.

ps. I wouldn't let a dealer change the air in my tires. :rev:

I trust your thoughts xviper, but I honestly dont see myself drenching my engine... I prefer very specific applications when cleaning under the hood. ol'dood's products sound pretty cool, but I'll prob use windex and a towel, with a moist rag (so the best of both worlds). And yes, I am trying to preserve the hoses, but while making them look nicely shined.