My dad never changed transmission fluid 1st gen 160k miles

Must be a 2nd/3rd gen thing. I've never had a vehicle with those.

 

They must maintain a minimum spec, so effectively yes. I use DOT 4 Prestone though

 

Its not an any gen thing. These fit on the bleeder screws which are generic and haven't changed in design ever (some are longer/some are shorter and some have different thread sizes but that's it)

 

And yet, I've never had a vehicle come with them.
99 Taco
99 4R
04 Saab
03 Tracker
15 Golf
13 Versa
03 ES300
So unless all of them fell off, I'm calling BS

 

Mine may have come on my stainless speed bleeders. But since these rubber caps (like the ones for zerk fitting as well) have been out there forever I would think after your many vehicles vehicles you would have added them after just one clogged up bleeder screw. This is an 18 pack but you can get 60 packs if you have a lot of cars/bikes etc...


So note to all. If you don't have them already spend the couple of $'s and get them. And its so cheap you can get spares in case one dries up and falls off or just gets lost.

$6 Tondiamo 18 Pieces Brake Bleeder Caps Rubber Caliper Nipple Caps Dust Caps Brake Bleeder Screw Covers Grease Fitting Caps for Cars and Motorcycles

https://www.amazon.ca/Tondiamo-Bleeder-Fitting-Caliper-Motorcycles/dp/B09K3L13LK?crid=2LKLCOQJDEGK4&dib=eyJ2IjoiMSJ9.AQbCBgwOL1Pp1FhhFIjwWRPUuT06bUNPocjbARq25Rqt7kdOjX45470a9_XovTVJoBmyvXZQT2yjgnli0eDpT7fcIndOmKIO-kNRkUVWCoQ9u_rOwSQUMw9G3z6dWXCR-pH8bqjqNIeERRYyccy4W-EDdnmGWeav-Q4z1idhwqTA4JeH8kxuOk0jVUjtrV9TlJAH8Pny9G8UuzotM-SXdRS733phybNUZS2SLeE76kSn0pwy-XmKncoDnVz8_ScIUHVYPtHgoqG6inP_rRqJ5gn-8BuywYrf1GFMvJqj1wI.O3d-teEAyg0qS9eYzHw0EyRwlw4m7JNM52gWVkVndU8&dib_tag=se&keywords=bleeder+screw+plug&qid=1713713566&s=automotive&sprefix=bleeder+screw+plug%2Cautomotive%2C81&sr=1-18

 

All new vehicles come with them in one form or another. They do get old and dry rot and fall off or a lazy tech might not put them back but every single vehicle came with caps from the factory. They keep the dirt and mud out of the bleeders. If you're missing them you can buy a 50 pack for like $10.

 

They really don't need them. Open the bleeder step on the brakes it will purge them. 800 to 2,000 psi in normal breaking.

 

These are utterly unnecessary.... But feel free to obsess over it ig

 

Tell that to

And ask if he would rather spend maybe $2 on those . Are they unnecessary I guess not but wouldn't go as far as saying they are utterly unnecessary. Much like the plastic caps on tire valve stems are unnecessary??

The hole in the bleed screw goes down and exits near the threads in the caliper. If you really want salt water in there as well then you have never had one of these snap of at the head because it was so badly rusted.

 

I can't seem to find them right now but I swear some vehicles come with caps that go all the way down so they cover the threads. Would be a good investment for the Rust Belt.

 

Those sound interesting. Let me know if you can locate them. I don't need them since my bleeders are stainless steel but i can pass on the info...

I have seen the ones that have a retaining strap thingy to keep them from getting lost.

 

Good question. One of them did have remnants of an old cover, wasn’t sure what it was at the time..
Might not have been a problem if I had been bleeding using the pedal, that pressure may have broken through, but the vacuum pump I used couldn’t break through the debris.

I don’t have valve stem covers either

 

Two different animal's. Caps on tire yes, (35 psi) caps on bleeder screws are not necessary. Good hard stop 2000 psi in the breaking system there is no way any thing is going to get by the bleed screw. Now a cap does nothing for the bleeder threads in say a clapper so if you are real concerned remove them and coat them with anti seize but don't forget the rear ones they are much smaller and brake easily.

 

From power stop brakes

https://www.powerstop.com/resources/how-to-bleed-brakes/

Step 9 – Cap Bleeder Screws and Reservoir
Use some brake cleaner and a towel to wipe any spilled brake fluid off your calipers and cover the bleeder screws with the rubber caps you removed earlier. Do a final check on your fluid level and cap off the reservoir.

But what they do they know. They only make brake parts.

https://www.brakes-shop.com/brakepedia/fluid/how-to-bleed-brakes-the-right-way

Locate the bleeder screw at the rear of the caliper body (or drum brake wheel cylinder.) Remove the rubber cap from the bleeder screw – and don't lose it!

Cant find a single mention of "just throw away these utterly unnecessary things"

 

Same purpose. Keep crap out of someplace it shouldn't be. And about the same ridiculously low price. You can get 60 of these for $9. That's 15 cents a piece. So on a regular vehicle with 4 calipers that 60 cents...

 

Never too late!

 

For those throwing out brake pressure as say 2000 psi and thinking this would blow out any blockage, you are neglecting the si (square inch part)
I dug up a old bleeder screw. The diameter of the bleed hole at the bottom was 0.045 inches.
That works out to an area of 0.0015904 sq/in
Since according to pascals law given the same pressure the force is proportional to area.
So the actual force applied to that tiny little hole is max of 3.18 lbs (not 2000).
And since normal (not panic) brake pressure is 800-1200 its probably half of that.
That's never going to do the job if its totally blocked.

Since pressure equals force per unit area, then it follows that

F1/A1 = F2/A2

2000/1=3.1/0.0015904

https://www.grc.nasa.gov/www/k-12/WindTunnel/Activities/Pascals_principle.html

I knew my university physics text book would come in handy someday

 

Update I sorta found them. 19 Highlander rear caliper. Unfortunately, Toyota doesn't seem to sell them separately from what I can find but here are a couple of pictures. They were on a 10mm bleeder but test fitting they seemed to fit on an 8mm bleeder just fine. It may need some trimming vertically depending on bleeder protrusion height.

 

Is that one piece or two? Just looks like there is a dividing line between the cap and sleeve?