Coolant Bottle Empty

I noticed my coolant bottle was empty so I filled it. It seems to empty after about 10 miles of driving. I figured the leak would be easier to find if I let more coolant spill out, so I kept refilling the bottle. The inside of the engine bay is splattered with pink spray all over, but the leak did not become obvious. I think its in the front and the fan is spraying it everywhere. Every time I've checked the radiator when the engine is cold there has been coolant visible at the top and the fins in the radiator looked submerged. I have gone through 2 gals of coolant and stopped filling the bottle since the level in the radiator seemed stable. Now the level in the radiator is lower.

How should I find the leak?

 

I think you have a leak...

The radiators like to fail after they're 10 - 20 years old. If the plastic is brown instead of black you have a winner! Also, check the radiator cap. One time I found that the silly little hose that connects the radiator to the expansion tank was the leak!

There's a dozen or so coolant hoses connected seeming everywhere, any on of which could be the source of your leak.

And finally...the water pump. When was your timing belt (and water pump) last replaced?

You might want to invest in a pressure tester to hasten your investigation.

$105 OEMTOOLS 27068 Universal Cooling System Pressure Test Kit, Automotive Radiator Pressure Tester for Coolant System, Diagnostic Tool for Radiator and Reservoir Leaks, Includes Adapters And Case

https://www.amazon.com/OEMTOOLS-270.../dp/B071W9B31L?smid=A2W86Q8280F2Q3&gQT=1&th=1

 

If you're spraying all over the inside of the engine bay, it sounds like your radiator cap is fucked. Might want to address that. They go bad, you know.

 

I had an issue with my 3.4 building a ton of pressure in the cooling system. It was not flowing back and forth through the overflow bottle, just building a ton of pressure and spraying from around the hoses and seams. I replaced the radiator cap with a new one but it didn't change anything. It wasn't until I went to the junk yard and found 3 caps and tried them all where I found one that lets the pressure flow into the reservoir and not build up all that pressure within the system

 

Thanks for advice! I'm going to bite the bullet on a pressure testing kit and a radiator cap; if the pressure tester doesn't reveal the leak I'll assume its the cap. If its not the cap, ill have an extra cap for when it does start leaking. I didn't know the caps went bad. Can't find a part number for denso radiator caps, do the denso radiators come with caps?

The water pump and timing belt were done last august. Thats when my starter broke... I'm also worried I damaged the radiator leaning on it while pulling the intake to access the starter. The truck hasn't been used much recently, only a few hundred miles since then.

The pink HOAT coolant is anti-corrosive right? So I shouldn't worry about cleaning it off of everything in the engine bay?

 

16401-20353 (NOTE: the old part# ended in -72090), it's only $13 on pickup from my local dealer (if I order it using that Toyota Official Parts site link).

 

Oh, and the directional spray suggests it is, in fact, the radiator cap. We have some pics on here of someone who actually had the bottom half of their cap fall out. It's spring loaded underneath the cap. Not asking you to be a CSI detective here and look at blood spatter, but spatter directionality and voids will tell you a lot about where stuff is coming from. Just know: Liquid will ricochet off stuff, so ...

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That is an understatement. I thought letting it spray more would make the source more obvious but there is so much spray everywhere its really been puzzling to me. It seems to be hitting that refrigerant hose and the oil fill spout a lot. The hood is getting a lot of spray too.

My cap seems relatively clean, no obvious collection of coolant. I didn't realize it was a pressure release and there is no spout/outlet. There is no puddle in the bottom of the engine bay either. I definitely think the leak is somewhere in the top front/ near the radiator. Cap is $30 from my dealership. I'll see if that works then buy a pressure testing kit.

You guys on this forum are a life saver!

 

Yeah, it definitely doesn't look like it's coming from the cap, I agree.

A few places to look at:

• Check your larger hoses for possible pinhole leaks.
• Radiators are a slab of metal fins with plastic caps, and thin liquid filled tubes throughout; they tend to leak at the base of the plastic cap, and at those tubes, but sometimes it doesn't show up until you're at-temp, and revving the engine.
• There's a small coolant hose that passes thru the bottom of the throttle body, check it carefully too
• There's a bolt hidden behind the smaller tube in the pic, about 1-2" up from where the overflow tube meets the overflow bottle. I think it's a 10mm. Pop it out, push the fan shroud forward; any fluid on the back of it? Repeat on the other side, there's a similar bolt there.
• Look for voids, places where there's no coolant spray, and see if you can figure out an angle fluid could spray and leave a void in that spot. Look for puddling, pink coolant usually leaves crystalization when it puddles.

Really, people should be proactively changing their radiator at the same time as the timing belt, if you ask me. They're usually good for 125k-150k miles, but I wouldn't trust them much past 125k. Especially not when you consider you can destroy your transmission if the trans cooler line passing thru the bottom of the radiator leaks. Your coolant needs to be changed every 100k if you're using the correct pink SLLC coolant Toyota urges you to use, so why not do the radiator and timing belt at the same time, y'know?

But if you can track down roundabout where the coolant is coming from, you'll answer your questions. Is it above, behind, left or right of the radiator? Or is it possibly one of the hoses, or is it maybe seeping from one of the metal housings/bibs where the coolant hoses clamp onto?

 

Shifty' said, "Oh, and the directional spray suggests it is, in fact, the radiator cap. We have some pics on here of someone who actually had the bottom half of their cap fall out. It's spring loaded underneath the cap."

That was me and my issue.
Installed a new Denso radiator and cap in the winter, was never burped 100%. Never had any issues in the cooler weather. But, when I was driving in the mountains at115 degrees in started spraying when hitting the fan.

Resolved the issue with a new TRD cap and a good "Burp".... no problems since. Link to photos below

https://www.tundras.com/threads/i-could-use-some-help-sourcing-a-coolant-leak.145284/

 

I finally got a pressure tester and then the required adapters.

As soon as I put 5 psi into the radiator (like 3-4 pumps worth) it started spewing out the top seam on the passenger side facing the bumper. The radiator must not be level since it ran along the seam to the drivers side as well as flowing downwards. It leaked way more aggressively than it seemed to from normal driving quickly creating puddles. So I ran the engine with the pressure tester attached to the radiator and I didn't see any pressure build up while idling even as the coolant gauge showed the coolant was warm. I did notice more leaking from that spot while idling. I guess I was under estimating how bad the leak was due to lack of coolant puddles after driving etc. Now that I can see it, it seems way worse than I thought it was. Maybe the pressure tester opened the leak more? I think intermittent leaking from that point would explain the coolant everywhere, but I wont be surprised if there are other leaks. I have a new denso radiator coming in the mail, should arrive tomorrow. Fingers crossed it shows up ok.

I've been watching videos and reading threads here about swapping radiators and have a few questions.

1. With the radiator disconnected will coolant and/or atf drain from the rest of the car? In other words can I disconnect the radiator without draining all the coolant and atf first?

2. If I can swap the radiator without draining all the atf, do I need to worry about bleeding air from the atf after? How much atf should I expect to lose/top off? Would you re-use the old stuff (I'm under the impression there are different schools of thought on atf fluid, erosion in the transmission, and transmissions slipping)?

3. If I can swap the radiator without draining all the coolant, how much will I need to refill the new radiator? Would you re-use the old stuff if it looks ok?

4. Does the radiator cap act as a valve between the overflow bottle and the radiator? Based on Lundy's thread I'm thinking about bleeding air from the coolant by idling the truck on a hill with the overflow bottle empty so there is no back pressure for air to burp through the bottle.

5. Should I be aware of anything else? Right now I'm only focused on not spilling coolant or atf.

 

My thermostat was leaking from the lower part of the housing, dripping right onto the belt which would sling it everywhere. Particularly onto the underside of the air box. Make sure to check stuff from different angles and you might find a much bigger residue hint.

 

If it has sat for a while most atf will have run down towards trans. Your'e going to loose a little ATF.
What I did was use an old, CLEANED, spark plug and popped it in each hose as quickly as possible just in case.
I caught all of the fluid, and poured it from the cooler into a small jar to measure for topping off the transmission later. I think it was about 3 ounces.

No I would definitely not reuse any coolant, or transmission fluid.
IF I remember correctly it takes 3-4 gallons coolant for the entire system so the radiator will only hold little over a gallon.
I ordered 2 cases of aisin coolant, and still had about case and 2 gallons left I think.

 

Answers to questions in post #11. Get a couple of golf tees and you can plug the transmission line so you only lose a few drops of ATF. Drain the radiator and disconnect the hoses. At that point you can replace the radiator but if your coolant is more than a year or two old, you may want to drain the block at the little drains. Be sure heater knob is rotated full hot. Use only Toyota pink coolant. I also recommend swapping out the OEM side brackets to your new radiator.

 

You'll only loose the ATF that is in the cooler/warmer but it wouldn't hurt to plug the lines.

You have an 02, this would be a great time to do a drain (from the transmission pan drain plug) and fill (you actually have a dipstick it's easy). It'll take 3 to 4 quarts.

Don't reuse any of the fluids you drain, and make sure that your coolant is pink when it comes out, if its any other color you need to do a flush and refill with proper pink coolant.

You should replace the rad cap with the new radiator. I would do upper/lower hoses and a thermostat while it's all apart.

For bleeding out air get yourself a coolant fill funnel. They are cheap and help out quite a bit with bleeding air.

$23 EPAuto Spill Proof Radiator Coolant Filling Funnel Kit

LINK

 

I got the new radiator in and wanted to thank the forum again. If it weren't for the high quality contributors on this forum this job would have been way harder for me.

For whats it worth I wanted to upload my experience.

The Denso radiator from rockauto seemingly arrived ok, but the box was damaged and there was surprisingly little packaging material in the box.

I collected 1 gal of coolant and 4.5oz of ATF. I spilled a bit of coolant taking the radiator out and a little bit of ATF when disconnecting the lines. The old spark plug idea worked perfectly. I also used the rubber caps that were on the new radiator's ATF spigots to stop the drips from the old radiator while I pulled it out. Then I attempted to pour as much ATF from the radiator as I could. I collected about 2oz ATF from the lines before getting them plugged and another 2.5 oz of ATF from the radiator. More coolant came out when I attempted to pour the ATF, I should have expected that but it wound up on the floor. (Most of spillage in the pictures is from pressure testing to find the leak, the spillage from pulling the radiator was relatively minor in comparison).

Putting the new radiator in was quick once I realized the fan shroud was in the way. The ATF spigots got caught on the bottom of the fan shroud (which was resting on the fan). The tabs on the radiator were through the holes on the truck but the bolt holes weren't aligned. Since the tabs made it to their holes I didn't realize the radiator was caught on the fan shroud and I tried to wiggle the radiator into proper position. I hope I didnt put too much force on the spigots or the fan. I read the spigots are a weak spot leading to the pink milkshake problem, and the fan bracket ages so may not have much life left in it.

I pressure tested this morning up to 11 psi for about 5 min. Seemed great since the old one leaked at 5 psi instantly. The radiator didn't leak, but the coolant lines going to the oil filter housing starting dripping slowly after the 5min mark. I didn't warm up the engine before pressurizing so I'm hoping at temp that doesnt happen. Also based on my earlier testing it seems the coolant doesn't get to 11 psi often. Afterward I noticed a wet spot on the lower seam of the radiator, no drips though.

 

Always appreciate a good followup, hopefully this resolves your issue.

If not, you may have gotten a damaged radiator - smart idea to take pics. If you install a part and it shows issue, you can email RockAuto back (either using their website form, from your account page or by replying to the order email, IIRC) and notify them with pics of the box and pic of the leak, and they should resolve the issue for you.

Denso is, sadly, known for the lack of insulation in their packaging. It's not a problem for vendors who get 10+radiators in a bulk box. But when you order from RA specifically, they often have RA drop-ship directly to the customer, and in singular format, they don't always survive as well. With vendors like scAmazon, you're pretty much at the mercy of however the person at the warehouse is feeling, and how much abuse they've seen from getting tossed around whichever warehouse they shipped from.

 

I wonder if Summit ships better?

 

No experience there.

I will say - and I posted this in the Lunch Table thread - I was there with my youngest (12) who is really getting into cars lately, and found a Denso for DC 1st gens they had on the shelf. In additional to damage from "assholes dragging fingers across the fins", it appeared to have the typical shipping damage in spots I've seen on here. So the answer to that may very well be "no". I'd hope Summit would box-in-box if the part is in their warehouse. They're usually better than anyone I've ever ordered auto parts through over the last 20 years (and I've been shopping with both RA and SR for longer than that). But I also know SR drop-ships direct from vendor warehouses when they don't carry said item in their regional warehouses.

Interesting tidbit: When I ordered by 150A Sequoia alternator from RA recently, it drop-shipped direct from the Denso warehouse in CA. When I ordered Honda door actuators for a 3rd gen CRV last year, it drop-shipped direct from Dorman (I bought the parts from Dorman versus paying 3x for OEM, and wasn't disappointed)