Pretty agressive formula and you don't need to breathe it. It can be pretty nasty stuff. Might damage any painted components.

I would only use it to degrease or clean smaller individual components. There are other degreasers for an entire engine compartment that would be a lot better to use .

Thanks for your reply!

Contact cleaner is likely to be a lighter and much more fast-evaporating than break cleaner.

I don't think there'd be a problem using break cleaner in engine compartment though, no. Except maybe not best for cleaning the fuse box.

Edit: Also agree with MichMan ... for spot cleaning most places probably fine, for whole compartment, go w/something designed for the purpose.

Yeah for the fuse box, I prefer the power washer. /s

Be careful before using non-clorinated brake cleaner over coated areas - it melts the epoxy on your garage floor where regular brake cleaner doesn't. On the other hand, regular brake cleaner will melt softer plastics like those in car stereos, but is okay on the more rugged plastics in the engine compartment.

In cleaning an engine compartment brake cleaner is the first thing I have always used. Anything left that hasn't come off can be scrapped off or picked out. Stay away from the non-clorinated.

It's been a handful of years since it melted the floor in my ex's garage - it made one hell of a mess. I had replaced the front brakes on her car and what washed off fused into the epoxy. There was nothing I could do to clean it up prior to letting the car down and it stayed soft long enough to leave an imprint of the tire tread for a few feet. For the other side I put down a couple layers of cardboard first. It may be possible that the formula has been improved. The cleaner I currently have is non-chlorinated and was used to clean off the entire front of a motor that I changed out the AC compressor on. No problems.

Turns out the stuff I have *is* non-chlorinated (CA here). But, I should be fine, since I don't have a garage.

Very good to know about the epoxy anyway.

I find that when looking at a motor for leaks or stains, peering just over the fenders from as low of an angle as possible helps. Often those trying to sell or buy a vehicle will not look from as far forward (near the headlight) or as far back (by the hinge) as possible, they stand by the wheel well and miss the hidden areas. Have some zip ties and/or electrical tape on hand for any wires that may be hanging or out of place. Wires, hoses, and tubing are easily cleaned by spraying some WD40-type product on a rag, wrapping it around, and pulling for the length of it. For cleaning up your hands keep a bucket of soapy water handy. Good luck.

Removed my alternator and just got another, but wanted to clean up around there before installing it.

Also, I spotted a dangling (cut) green wire in that area that I'm trying to identify, so removing gunk. Still have not ID'd it yet.

Thanks

On many metric motorcycles a stator is used instead of an alternator, with the voltage regulator separate. Sometimes when people have change out their batteries they connect the negative first, and then the positive. What happens is they end up blowing out a diode, which in turn can burn out the stator. That is why the instructions always say to disconnect the negative first; when reconnecting it's the positive first. Anyway, I ramble...

My diodes were blown, and I did have a bad habit of thinking that the + connected alone was safer than the ground connected alone.... *totally* the opposite of the correct way, sigh...

I am having a helluva time identifying this broken wire hanging below where the alternator goes! I have the full FSM for my vehicle (2001 4runner) and have now spent two days looking at nearly every page (over 2000!) trying to id which sensor might be missing it's connection. I want to figure this out before reinstalling the new alt. Arrgh.

I will write up how to know what it is and message you.

Don't use it on anything hot.

Fortunately finding an area of that high of a temperature on a typical car is difficult, especially if the engine has been turned off and is being worked on. But, as I sometimes say about some media outlets, one person out of hundreds of millions can do some outrageous act and it gets portrayed as the norm.
I do appreciate the info you gave however. I was unaware of the perils and conditions under which they existed until now. As soon as I saw tetro, carbon tet came to mind, as well as when seeing per did perchlorate.
In addition, its effects on memory help to explain why as a Iong time mechanic I'm so easily confused.
A good find none the less.

it always puzzled me how ski resorts can make snow when it's close to 40 degrees. But you have a point.

Overall, the contact cleaner is better if I have only a few hours before I have to report to my job as a commercial airline pilot, but want to get my freak on for a while first.

But if I have a hotel room for the weekend, some crank, and a couple of "friends" (wink, wink), then the brake cleaner is the bomb.

"The More You Know..."

Next thing you will tell me that people wash mower decks...

Normally, I let sleeping dogs lie, but I'm trying to visually inspect certain parts/areas that are covered in gunk, so...

and worse, then I must interpret and understand them, which would no doubt lead to me posting on DU. So, I cut out the middleman.

But thanks for the most logical answer.

I didn't want to do a thorough cleaning ("thorough" is his middle name), just needed to spot clean some areas using what I had on hand.

It's my device, some setting somewhere

Used it for decades.
https://pj1.com/product/pj1-pro-contact-cleaner/