Don't touch your PetCock?

[Gokhan]

Originally Posted By: SumpChump
Originally Posted By: Gokhan
You mean the radiator drain plug? Those hardly ever break and in the unlikely case that they do, you can buy a new one for less than $10.

Yep the drain plug aka petcock. Plastic. They usually are flimsy and squeek-creak when turned.

They are plastic because they aren't meant to be gorilla-armed. They are tightened as much as you would tighten a faucet handle. As I said, there is an O-ring at the tip of it that seals when seated. I wouldn't consider the Toyota radiator drain plugs flimsy. I've never had any issue with them. If they had made it from metal, people would crack the radiator tank gorilla-arming it. Worst-case scenario if someone decides to gorilla-arm it -- you buy a new one from the dealer for less than $10.

 

[oilpsi2high]

Originally Posted By: Tegger
Originally Posted By: Chris142
pull a hose if possible.

If the block drain is lower than the thermostat housing, then pulling a hose will leave old coolant in the system. Bad idea.

OP should read the shop manual and find out how to do the job RIGHT.


x2. My car has seen 8 winters and the shop manual says to drain by the plastic petcock on the bottom of the radiator. Absolutely zero issues. Don't force it and you'll be fine most likely. I opened and closed mine with my hand, no tools necessary.

 

[HTSS_TR]

Originally Posted By: Chris142
Ya the plastic ones like to break.new ones are available for oem rads but theres a zillion styles in the afternarket.pull a hose if possible.

I changed coolant in my 21 years LS400 about 6-7 times already, never had any problem with breaking petcock.

The first change was hard to loosen the petcock, but was very easy after that on every change.

 

[CT8]

Petcocks can and do break. I used to love asking the parts girl for a petcock, She would turn bright red and loose it laughing saying petcock all the way to the shelf and back . It was fun!!

 

[artificialist]

Sometimes old petcocks break, but what is even worse is that sometimes when removing one from a very old radiator, it breaks the plastic end cap.

My dad said that when he had a 1968 Chevy Biscayne, there was no radiator petcock. Instead, you were supposed to cut off the old radiator hose to drain the coolant, then install a new hose. That might not be a bad idea when dealing with an old radiator that has plastic end caps.

 

[901Memphis]

My 99 Taurus petcock broke a couple years ago, the end of it was shaped like a large plastic nut and the nut part broke off of the part where it meets the threads. It broke off while tightening it even though I was gentle. I way able to remove it luckily because where it broke off there was an Allen wrench sized hole in the middle of the plug.

I got a new Dorman part that uses a wing nut style tip so no tools required and won't be as easy to manhandle.

My Buick uses one of those weird ones where you loosen the plastic knob but it doesn't come out it just opens another hole. No trouble with that yet.

But I did break a friend's drain knob off his 99 Cirrus a couple years ago that thing was cheap and fragile. We ended up having to JB weld the hole to seal it. The resulting coolant flush ender up ruining the car as it was the first time the car had any cooling service being a 99 it should have been serviced before 2012... It was rust colored mud no matter how much we flushed it. Can't believe how long it ran on what must have been the FF. Only 67k miles on it too going to the junkyard.

Eventually the new coolant sprung a leak at the freeze plug.

 

[HerrStig]

Last radiator I changed because of a cracked plastic top tank the petcock was so hard to get to I pulled the hose instead. Thereafter I tested the petcock on the old radiator (150K) just for giggles and it broke. Kriol, PB Blaster, even WD 40 will free up a stuck hose but they don't seem to stick to plastic as often.

 

[Michael_P]

I have greased the threads on metal petcocks and Sil Glyded® plastic ones. Never had an issue. I always clean the area prior to draining.

 

[Gokhan]

Well, the OP has a Toyota. My Toyota's radiator drain plug never broke during the 25 years the radiator lasted and it saw many coolant changes. I replaced the radiator about 5 years ago. I will send the OP the 30-year-old, as-good-as-new Toyota petcock if the one on his brand-new Toyota breaks.

 

[Al]

Been working on my vehicles for 50 years. Never had one break. Just tighten it lightly. It has a rubber seat.

 

[doublebase]

You can touch it, but you might go blind.

 

[Koz1]

I have turned door handles right off the door at work by accident, I better get my wife to turn the PetCock to be safe.

 

[Sayjac]

Originally Posted By: Al
Been working on my vehicles for 50 years. Never had one break. Just tighten it lightly. It has a rubber seat.

Not quite 50 years... yet, but my results are the same.

This thread's ironic to me as I've frequently read some guys doing some GM trucks with no petcock option complaining about not having one for the job. Having to use the lower hose, while not as good/easy IME as using petcock for simple rad d&f, wouldn't want to think about doing a distilled flush series that way. I'd say just me, but based on this thread and others I'm not alone. Strokes for folks I guess.

 

[01rangerxl]

I use the petcock whenever there is one and it will actually drain.

On my own truck, this has never been an issue. The cooling system has never been dirty, so the coolant flows from the drain with no issues. Even though it's slower to drain compared to taking the lower hose off, it is much cleaner and less overall hassle as I don't have to deal with the tension clamp on the hose. Also, from the petcock it drains straight down without splashing all over the place.

I have run into situations where there is so much junk at the bottom of the radiator that little to no coolant comes out of the petcock, and then I use the lower hose. Also, if I feel like I may break the petcock getting it to open, I opt for the hose.

I figure the manufacturers put the petcock there to be used. There's no need to drain coolant on the assembly line, so they aren't doing it for their own benefit. It is one of the few DIY considerations they give (and not all do), so I use it. Besides, if opening the petcock causes a leak or other problems, the cooling system has much bigger issues anyway.

 

[asand1]

On my Nissan it is just a plastic screw with a rubber washer.

Even with 300,00 miles and a cracked upper tank, the "petcock" (really just a drain plug in my application) was free, clean, and always able to seal. The new Koyorad I installed still uses the same plug and I still treat it the same.

I always used syl-glide after each drain and didn't go ape doody on the screw driver to tighen it.

 

[CELICA_XX]

The plastic one on my Toyota was tight enough that I needed pliers to remove it, but I was gentle with the removal / installation and everything was fine.

 

[Lapham3]

I've never had a problem with a plastic drain plug and don't really want to tug around with a heat fused on rad hose if I don't have to=I'd probably find a way to break the rad